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Episode Notes

Source / episode info

  • Episode: 491
  • Title: Divine Intervention Episode 491: USMLE Step 2/3 Rapid Review Series 106
  • Published: 2023-11-27
  • Source: Episode page

One-liner

Episode 491 is a rapid review emphasizing critical multi-system processes: Tumor Lysis Syndrome (TLS) with electrolyte derangements; Spinal Cord Compression (SCC) management protocols; Superior Vena Cava Syndrome (SVC); and Colorectal Cancer workup/metastasis patterns.

High-yield summary

  • Tumor Lysis Syndrome (TLS): Characterized by hyperkalemia, hyperphosphatemia, hypocalcemia, and hyperuricemia due to massive cell death from malignancy or therapy; treatment requires aggressive hydration and urate-lowering agents (Luprioral, Rasburicase).
  • Spinal Cord Compression (SCC): A medical emergency requiring immediate diagnosis via MRI. Initial management is always IV steroids, specifically Dexamethasone, followed by radiation or surgery.
  • Superior Vena Cava Syndrome (SVC): Caused by external compression of the SVC (e.g., lung cancer, lymphoma); symptoms include facial/neck swelling and can cause signs mimicking heart failure (e.g., JVD).
  • Colorectal Cancer Metastasis: The most common site of metastasis is the liver, due to the portal venous drainage system; multiple liver lesions are highly concerning for poor prognosis.
  • 5-Fluorouracil (5-FU): A chemotherapy agent that works by inhibiting dihydrodipicolinate synthase, disrupting pyrimidine synthesis, and is commonly tested in board exams.

Learning objectives

  • Differentiate the pathophysiology, clinical presentation, and initial management steps for Tumor Lysis Syndrome (TLS).
  • Identify the classic signs and differential diagnoses associated with Spinal Cord Compression (SCC) and understand the acute treatment protocol.
  • Recognize the causes and physical exam findings of Superior Vena Cava Syndrome (SVC) and its implications.
  • Determine the most common site of metastasis for colorectal cancer and interpret clinical findings related to GI bleeding/anemia.
  • Understand the mechanism of action and clinical use of key chemotherapeutic agents like 5-FU.

Board exam buzzwords

ConditionKey FindingAssociationBoard Exam Tip
Tumor Lysis Syndrome (TLS)Hyperkalemia, Hypocalcemia, HyperphosphatemiaMalignancy/Chemotherapy; Phosphate binds CalciumAlways remember to give IV fluids and a urate-lowering agent (Luprioral or Rasburicase).
Spinal Cord Compression (SCC)Back pain, Saddle anesthesia, Muscle weaknessHistory of malignancy (Prostate, Myeloma); MRI findingsInitial treatment is always high-dose IV steroids (Dexamethasone) regardless of the underlying cause.
Superior Vena Cava Syndrome (SVC)Facial/Neck swelling, JVDLung cancer, Lymphoma; Widened mediastinum on CXRIf definitive therapy isn't available, diuretics and elevating the head of the bed can help manage congestion.
Colorectal CancerMicrocytic anemia, Occult GI bleedingPortal venous drainage -> Liver metastasisThe liver is the most common site of spread; multiple lesions are ominous.

Rapid review table

TopicKey PointContextExam Relevance
TLS ManagementAggressive hydration + Urate-lowering agentAcute renal failure secondary to high cell turnover (e.g., lymphoma).Must know the specific drugs: Luprioral, Rasburicase.
SCC Initial TreatmentIV Corticosteroids (Dexamethasone)Compression from any malignancy (Prostate, Myeloma, Lymphoma).The first step is steroids; radiation/surgery follow later.
SVC SyndromeUpper body congestion (Face/Neck swelling)Mass effect compressing the SVC (e.g., lung cancer, lymphoma).Remember that JVD and facial edema are key signs of obstruction.
CRC MetastasisLiver involvement via portal circulationColonic drainage into superior/inferior mesenteric veins -> Hepatic vein -> IVC.The liver is the primary site; multiple lesions suggest advanced disease.

Board-speak -> diagnosis

Board-speak / Vignette phraseDiagnosis / ConceptWhy it fits
19 y/o with Hodgkin's lymphoma presents with hyperkalemia, hyperphosphatemia, hypocalcemia, and acute kidney injury.Tumor Lysis Syndrome (TLS)Massive cell death releases intracellular K+, PO43-, leading to calcium binding; requires aggressive hydration and urate management.
A patient with a history of prostate cancer develops progressive back pain, muscle weakness, and saddle anesthesia.Spinal Cord Compression (SCC)Classic triad/symptoms suggest compression; immediate diagnosis is required via MRI.
A patient presents with facial swelling and jugular venous distention (JVD), and the chest X-ray shows a widened mediastinum.Superior Vena Cava Syndrome (SVC)SVC obstruction causes upper body congestion; differential includes lung cancer, lymphoma, or thymoma.
75 y/o male with weight loss, occult GI bleeding, and microcytic anemia. Imaging reveals multiple liver lesions.Colorectal Cancer Metastasis to LiverCRC drains via the portal system into the hepatic vein/IVC; the liver is the most common site of metastasis.
A patient receiving chemotherapy for lymphoma develops acute renal failure with severe hyperuricemia.TLS ManagementThe combination of malignancy and therapy necessitates urate-lowering agents (e.g., Rasburicase).

Differential diagnosis / distinguishing features

SVC Syndrome

Key FeaturesDistinguishing FindingsNext Step
Facial swelling, JVD, upper extremity edema.Widened mediastinum on CXR; Lymphoma/Lung cancer history.Treat the underlying malignancy (Radiation/Chemo). If not possible, diuretics and elevating HOB.

Microcytic Anemia Causes

Key FeaturesDistinguishing FindingsNext Step
Low MCV (<80 fL), low Hb.Occult GI bleeding; Weight loss; Colon cancer history.Colonoscopy/CT scan of abdomen and pelvis to rule out malignancy.

Management pearls

  • TLS: Always treat the electrolyte abnormalities (especially hypocalcemia) first, often with calcium gluconate, before aggressive diuresis.
  • SCC: The initial treatment is steroids ( Dexamethasone ). Do not delay care while awaiting definitive diagnosis or planning surgery/radiation.
  • SVC Syndrome: While radiation and chemotherapy are primary treatments, supportive care includes diuretics and elevating the head of the bed to manage congestion.
  • CRC Workup: Colonoscopy remains the gold standard for screening and initial lesion identification; CT scan is used for staging and assessing liver metastases.

Don't miss

🚨
The classic triad of TLS (Hyperkalemia, Hypocalcemia, Hyperphosphatemia) must be recognized immediately upon suspicion of massive cell turnover.
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SCC management requires a staged approach: Steroids -> Radiation/Surgery . Do not confuse the acute stabilization step with definitive treatment.
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SVC syndrome can be caused by more than just lung cancer; aggressive lymphoma is a critical differential, especially in younger patients.
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Multiple liver metastases from CRC are highly predictive of poor prognosis and require systemic therapy.

Integration & clinical reasoning

  • Oncology/Renal: TLS represents a major intersection where oncology treatments directly cause acute kidney injury via electrolyte imbalance (hyperphosphatemia -> hypocalcemia).
  • Vascular/Pulmonary: SVC syndrome highlights how local mass effect can mimic cardiac failure symptoms (JVD, edema) by obstructing venous return from the upper body.
  • GI/Oncology: The drainage pattern of the colon into the portal system dictates that the liver is the most common site for metastatic spread from CRC.

OMM / COMLEX integration

🦴
For COMLEX: know these viscerosomatics / Chapman points, but don't let OMM distract from emergent diagnosis and management.
  • Standard emergency management takes priority over OMT in acute/unstable patients (e.g., TLS crisis, SCC). Stabilization and definitive medical care must precede any complementary therapies.
  • The concept of "knowledge atrophy" discussed by the speaker is a powerful reminder that continuous review and application are necessary for long-term retention, mirroring the need for consistent self-care in residency/practice medicine.

Concept connections / cross-references

  • For detailed information on general oncology principles and chemotherapy mechanisms, review [ Episode 123 ] (Hypothetical episode number).
  • Understanding vascular anatomy and venous drainage patterns is crucial; see [ Episode 456 ] (Hypothetical episode number) for a deep dive into the portal system.

High-yield association table

ConditionAssociationMechanismClinical Significance
Tumor Lysis Syndrome (TLS)Hyperuricemia, HypocalcemiaCell lysis releases nucleic acids -> Xanthine Oxidase converts them to uric acid; PO43- binds Ca2+.Requires urate-lowering agents (Rasburicase) and aggressive hydration.
Spinal Cord Compression (SCC)Multiple Myeloma, LymphomasDirect infiltration or epidural mass effect on the spinal cord.High suspicion in patients with hematologic malignancies; requires urgent MRI.
Superior Vena Cava Syndrome (SVC)Lung Cancer, Aggressive LymphomaExternal compression of the SVC by a growing tumor/mass.Can cause signs mimicking heart failure (JVD, edema); treatment is palliative and curative for the underlying cancer.
Colorectal CancerLynch SyndromeGenetic predisposition to GI tract polyps and cancers; associated with other "CEO" malignancies.Screening protocols must be aggressive in high-risk individuals.

Key terms glossary

TermDefinitionContextExample
Tumor Lysis Syndrome (TLS)Acute, multi-system metabolic derangement caused by rapid breakdown of large numbers of cells.Seen after chemotherapy for lymphomas or leukemias.Hyperkalemia, hypocalcemia, hyperphosphatemia, hyperuricemia.
DexamethasoneA potent synthetic glucocorticoid.First-line treatment for Spinal Cord Compression (SCC).Used to reduce inflammation and edema around the compressed nerve roots/cord.
RasburicaseAn enzyme replacement therapy (uricasase analog).Treatment of hyperuricemia in TLS.Converts highly insoluble uric acid into soluble allantoin, facilitating renal excretion.
Superior Vena Cava Syndrome (SVC)Obstruction of the SVC by an external mass.Seen with lung cancer or aggressive lymphoma; causes upper body congestion.Facial swelling and JVD are classic signs.

Study optimization

TopicStudy ApproachPriorityResources
TLSPathophysiology & Management AlgorithmHigh (Board-favorite topic)Review the specific drugs (Luprioral, Rasburicase) and their targets (Xanthine Oxidase).
SCCAcute vs. Chronic Treatment StepsMedium-High (Must know sequence)Memorize the order: IV Steroids -> Radiation/Surgery. Focus on why steroids are first.
Oncology Metastasis PatternsDrainage Anatomy & Common SitesHigh (Integration topic)Visualize the portal system for CRC (Liver); visualize the upper drainage for SVC.

Question pattern recognition

  • Electrolyte Crisis: Hyperkalemia + Hypocalcemia + Hyperphosphatemia -> Think TLS, especially in hematologic malignancies.
  • Neurological Deficit with Cancer History: Back pain/weakness/saddle anesthesia + Malignancy history -> Suspect SCC; order MRI and give steroids immediately.
  • Upper Body Swelling/JVD: Facial edema, neck swelling, widened mediastinum -> Think SVC Syndrome; differential includes lung cancer vs lymphoma.

Test yourself

Common mistakes to avoid

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TLS Mistake: Forgetting that hypocalcemia is often the most immediate life threat in TLS due to cardiac instability, requiring calcium gluconate first.
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SCC Mistake: Confusing the acute management (steroids) with the definitive treatment (radiation/surgery). Steroids are always first.
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SVC Syndrome Mistake: Assuming that a widened mediastinum always means aortic dissection; it can also be caused by SVC syndrome or other masses.

Common traps

⚠️
TLS Trap: The question might list multiple correct treatments (fluids, urate blockers, calcium). Always choose the intervention addressing the most immediate life threat (e.g., hypocalcemia -> Calcium Gluconate).
⚠️
SCC Trap: Being distracted by the underlying cancer type or specific symptoms; remember that steroids are given regardless of whether it's prostate cancer, myeloma, or lymphoma.
⚠️
CRC Metastasis Trap: Assuming metastasis occurs via systemic circulation (like bone); remember the portal system dictates drainage directly to the liver.

Original transcript with highlights

Original transcript with highlights

Welcome, this is Divine. Welcome to episode 491 of the Divine intervention podcast Into this podcast we're gonna be discussing the US Emily step-to-step three rapid review This is going to be series 106 series 106 Let's get right to it. So what if they give you a question about 19-year-old female and you're told that she's being treated for Hodgkin's lymphoma and then you're giving a bunch of laps, you know You're told that she has not been feeling well for the last 24 hours and even a bunch of laps You notice the potassium is six which is high You notice that a phosphate is extremely high. You notice that creatinine is like 3.5 or something crazy like that If you see something like this, what should you be thinking about? I really hope you're saying oh divine This sounds an awful lot like tumor-licase syndrome. This sounds an awful lot like tumor-licase syndrome. So How do people get this problem? How do we get these labs? Well, the thing is you feel we're gonna see this in the context in in in a classic context of Person having a malignancy usually some kind of hematologic malignancy because those things are really pretty sensitive to the therapies that we give well not all of them but many of them and As those cells die stuff is gonna spill out into the circulation, right? So you know for example potassium Spills out into the circulation because remember potassium is an intracellular ion. So they're gonna get hyperkalemia Your cells are pretty rich in phosphate, right?

Many cells use ATP as they explode. They release all that phosphate into the bloodstream and That phosphate what do you think phosphate likes to go after in the bloodstream? It loves to go after calcium So it's gonna bind up your calcium. You're gonna have high bull calcium And then think about it Also, these nucleotides and what not you're gonna spill them off into your bloodstream and then this fancy enzyme Xanthin oxidase is gonna cover it to your acid. So you're gonna have hyper your acemia hyper your acemia Honestly, this stuff I just discussed is extremely high yield. This is something that is an easy Arrow question on your exam. So make sure you know these classic Electrolite issues that you'd find in a personal normalizes syndrome They're gonna have high potassium and I've explained the mechanism behind pretty much all of it Like they're in a failure they get it because your acid is not great for the kidneys It's kind of simple powerful. So they're gonna have high potassium I've explained why they're gonna have higher acid. I've explained why they're gonna have high phosphate I've explained why they're gonna have a renal failure. I've explained why they're gonna have low calcium I've explained why make sure you understand again. That's the thing in this oncogeneration.

We live in please I'm not saying don't do on camera just saying do on camera also make sure you understand what you're on again So again, typically we tend to see this again with a lot of Himatologic malignancies although honestly you can pretty much see this with animal ignancy right But it's just way more common on the USM at least and people that have like aggressive lymphomas hematologic malignancies uh You can also see something kind of similar in a person that has rubbed of my alias Um just somewhat similar concept because more cells right have a ton of ATP. They have a ton of potassium in them So that's why many times if people have hypokillinia for example, they become like they have weak muscles Potassium is a supervide over a muscle So if your person has rubbed of my alias is for any cause right? Let's say you've been running a marathon where you have a crush injury or you took a bunch of ecstasy and you were dancing at a party for a long time Or say for example, you're taking a statin or you're taking a fibrate right especially a statin all these things are pretty pretty Myotoxic they can cause problems Again, notice all the different ways they can lead into this tumor lysis like concept right But again, you're gonna see the same electrode and anomalies whenever so many cells die right hyperchylemia Hyperheorysemia hypocalcemia high phosphate renofilia stuff like that So how do you manage tumor lysis syndrome?

Well, when the USM exams You're gonna try to correct these abnormalities right like they can really go that's the thing about tumor lysis syndrome It's a topic that is easy pickings for multi-system processes and disorders And many people always wonder what exactly do they test with multi-systems processes and disorders on the USM Well, this is an example of a topic like that Basically, if there's a topic that cuts across like so many different disciplines It's gonna be on the multi-systems processes and disorders I mean, look at the name multi-systems Processes and disorders processes if somebody has a lot of like processes that can cling to it Yeah, it's gonna be part of this section of the exam right so you're gonna try to create these electrolyte problems like for example They can give you an e-cage in this person showing topics t-waves.

Well, you're like oh no This is hyperchylemia kind of shining through Well, obviously you're gonna give calcium gluconeid first to stabilize the myocardium So those people don't die of a dangerous arithmety right so you're gonna try to correct all the electrolyte problems Right, what if they are asking you what is the first thing you should do for a person like first thing you should do in a tumor lysis syndrome fluids fluids fluids load them up with as much no more say as you can so you can achieve a like a vigorous Diariesis right as you give them all that fluid is gonna wash through their kidneys and wash away those nasty things And in those people should also consider a lupurinal A lupurinal is a zanctin oxidize inhibitor. So it's gonna prevent The production of uric acid so those people's kidneys don't keep exbisically like not working well Um, I remember if you don't see lupurinal as an answer you may see if they buxo start as an answer Fe buxo start Fe buxo start Fe buxo start That's another zanctin oxidize inhibitor Fe bu xos t Fe buxo start has exo in the name that can help you remember that it's a zanctin oxidize inhibitor alternatively on your exams you can use a drug like raspberry case or piglotti case Those are uricase analogs.

What is their job their job is to literally convert Their job is to literally convert uric acid which is not very soluble to Alantoink which is very soluble Um birds express this uricase enzyme right so far as it will come this figured out a way to kind of make it I use it in a drug. It's just that they're pretty expensive. That's kind of the the problem Okay, now what if they give you a question about a patient and they tell you that this patient is a 65 year old male And he comes in with over the last two days he has been having progressively worse than back pain And your tool that he has um a little muscle weakness Um He has and that he has had been urinary accident over the last You know 24 hours Um, and your tool that this person has Previous history of Long cancer std. Long cancer that was put into remission with chemotherapy When you see something like this honestly You want to think about this person having some kind of spinal cord compression spinal cord compression Whenever they want to give you a spinal cord compression question they can kind of manifest in many different ways right So they can bring it with you know Back pain you're gonna see a back and they're usually gonna give you some kind of cancer history Or to give you some antecedents in the question that tells you that Yeah, this person's kind of like a cancer candidate right so you're gonna see back pain I don't see all the muscle weakness, you know They'll have like Kote quina style symptoms.

You'll see saddle anesthesia, you know loss of bowel and bladder control right and Honestly for these people Um, if you're trying to think of a diagnostic test For your exam you want to go ahead and um get an MRI You want to go ahead and get an MRI MRI is Pretty much the best study you can use in a person that has spinal cord compression So what are you gonna do in a person that has spinal cord compression again the thing is kind of important to Understand What you do are cutely versus what you're gonna do over time That's one thing that's lost to many people preparing for the USM at least They know all the treatments for a disease, but you don't know what you're supposed to do are cutely Like many diseases have a particular acute treatment and a particular chronic treatment Many people don't break these things up right many times you see we'll get Lupus questions wrong or You know rheumatoid arthritis questions wrong because they don't have this kind of concepts down right So when a person has spinal cord compression the first thing you're supposed to do is to give IV steroids Right you're literally supposed to give IV steroids IV IV steroids especially the examethosone Thexamethosone is pretty amazing for this purpose Right, but another thing you can do right so you you've don't the dexamethosone That's always what you should do first.

That's always what you should do first But after that say for example, detailing the acute in that dexamethosone has already been given What are we gonna try?

Well The thing is you can try many other things right so for example you're gonna try Radiation radiation many times when people have like spinal involvement of malignancies Radio therapies usually going to be the smart thing that you're gonna you're gonna try or you therapy is usually the smart thing You're gonna try Although sometimes you can get surgery you can get like a your surgical whatever thing But many times with your therapies kind of a big big thing there Now what are the cancers that can cause this right like the classic ones prostate cancer In men breast cancer in women But don't sleep on some other malignancies that can honestly cause this problem right things like multiple my loma Multiple my loma can cause spinal cord compression I know it may not be something that you're used to seeing from many resources And then you see it on your exam and in your eyes pop open right so they can absolutely test spinal cord compression With multiple my loma they can test spinal cord compression lymphomas right leave it or know there are certain leukemias and lymphomas I love to go after those spines That's why in fact in certain malignancies if I'm not mistaken I'm pretty sure they do this with Some of these childhood cancers like ELL Um many times you're gonna give intra-thecal methodorexate Because these things can go to a person spinal cord and cause a cause problems Right you want to make sure you get all the cancer right so and I'm just gonna say let's give you chemo in your blustrum No, we're gonna also give you chemo in your in your spinal column actually so So don't be surprised if they throw this retelin formas they throw this with multiple my lomas Right, they throw this even with lung cancer.

I kill you not as you're saying this question Long cancer can certainly spread to the spinal cord Okay, just just kind of keep that in mind again The USM is these days many people think that they're testing so many new concepts. No, it's not just it's not new concept They are necessarily tested Yes, don't get me wrong. There's some new things. They're kind of thrown in there But there's some old things that they test they just tested in somewhat novel way Just to see if people can really still extend that thought process because if all you've memorized from your unkey decades first day cancer breast cancer causes spinal cord meds Then you're not gonna you're gonna have a lot of problems with questions like these That's why again is understanding the construct understanding the concept That matters matters the most right on some of the concept that really matters the most in fact I want to maybe talk about another thing that mean kind of help a person Here another situation where they do this novel business is with SVC syndrome right so preventative syndrome Pretty much every One when they see SVC syndrome The only cancer you think about for SVC syndrome is lung cancer and don't get me wrong many times on your exams Is lung cancer gonna be the cause of SVC syndrome?

Absolutely But what is another interesting way our friends at the MD is Contest SVC syndrome they can test it in a person that has lymphoma especially lymphoma that's very aggressive lymphoma that's very You know malignant that can cause SVC syndrome That's something you actually want to keep at the back of your mind for example, right? Because again, what is the construct or the concept of SVC syndrome? The concept of SVC syndrome is the your superior veneciva is literally encased by something That's the concept Whatever does the in-keysin can be different for many people. It can be lung cancer That does the in-keysin it can be Blum form that does the in-keysin so just kind of keep that in mind especially when you see SVC syndrome like symptoms in a younger person Especially a person that has not smoked malignant inform is probably gonna be the cause you're gonna be looking out for on your exams Right, but leave an informed is probably the cause you're gonna be looking out for in the exam Again, how those SVC syndrome present Basically Everything in the head and neck will be swollen for the most part at least you know on physical exam, right? So I'm gonna see the face is gonna be swollen the neck is gonna be swollen, right?

And you may wonder like divine while these things swollen well, it makes sense Here's the thing I think of the heart as an organ that Receives drainage from two big pipes one big pipe is the superior veneciva that pipe drains the upper parts of your body Right like your your face your neck Your upper extremities for the most part and parts of your trunk, you know But The IVC is the pipe for the lower parts of the body, right? So like your abdomen lever Some parts of your soft gas your low extremities, right? The IVC is the pipe for those So if you have a tumor that's obstructing the SVC pipe Then all the stuff that drains into it's they're gonna get clogged and those things get clogged You're gonna run into a bunch of problems So the face is gonna be swollen your neck is gonna be swollen Sometimes these people They'll have GVD right so again, it's not only like cardiac tamponade or heart failure that causes GVD SVC syndrome can also cause GVD Why? Because your jogger loved veins literally drain ultimately into the superior veneciva, right? And believe it or not really there's so many ways they can they can go after this Sometimes you can even give you a chest x-ray, right? You can see a widened media stining, right?

Again in this particular Rapid review series I'm trying to show you like someone usually is they kind of go after some concepts that are like real legit ways that It could be tested right that is beyond the classic thing you know They can literally give you a widened media stine them, right? Again, folks, widened media stine them doesn't always mean the other dissection Wide media stine them doesn't always mean pulmonary anthrax. No Why did media stine them can also include SVC syndrome? It can also include SVC syndrome Just gonna keep that at the back of your mind as you're studying for your for your example, right? So again, you're gonna see SVC syndrome long cancer patient presented a smoked right or present that again has a nasty nasty nasty lymphoma so What are we gonna do for this person that has SVC syndrome? Well, we're gonna fix their problem is we're gonna read it you're gonna read eat But if you don't see review therapy as an answer You want to try to basically just do something to control the malignancy bring it on the control shrink the tumor somewhat right and also don't forget that people to have SVC syndrome uh Besides the classic stuff like radiotherapy or transal control the malignancy you can also use diuretics to help these people out You know, these diuretics to help these people out and elevating the head of the bed is not a bad idea elevating the head of the bed is not a bad idea.

I can totally see our friends at the end being is gonna throw out a question Miss VC syndrome and the right answer is elevating the head of the bed, right? So we can just kind of keep this at the back of your mind as you're as you're studying for your for your exams, right? If this is the bugle of my answer, studying for your for your exams Um, so I guess let's maybe go ahead and discuss another another topic So what if they give you a question about a patient and they tell you that you know, this guy is a 75 year old guy and You know for the past two three weeks he has noticed some Red tingees in his stool and he has you told that over the past month he has lost like seven pounds or some you know amount of weight And then you get some labs, you know, this is MCV's 65 His hematocreat is like 24% or something really low Um, so then your axed um, you know for the primary disorder in this question, what is the most likely organ of metastasis? Well, I'll really hope you're saying a lever. Okay, so how did we how did we get there? Let's kind of break this down So this person clearly has colon cancer Right at least that'll be the most common thing right you see like GI bleeding Order person. It's probably gonna be a colon and weight loss. It's really gonna be colon cancer, right? Probably gonna be colon colon cancer. So colon cancer is kind of a higher topic to know these days for for the exam Uh for many reasons, right?

Not just for exam reasons, but honestly if you're a physician pretty much in almost any discipline You do you kind of want to be make sure you kind of recognize a colon cancer It's just something that presents in a lot of old people But it also presents a lot and a lot of younger people like you hear these crazy stories these days Of people in their 20s in their 30s stitch for colon cancer dying from it, right? Uh, imagine it's gonna It's kind of like a dietary thing going on there, but there's also gonna be genetic causes right there many genetic causes of colon cancer Like uh FAP familiar with the nomatos polyposes or person having um um Lynch syndrome you know Lynch syndrome is also associated with uh with colon cancers I always think of Lynch syndrome as being associated with the CEO malignancy, you know Think of like chief executive officer of a company. So like colon cancer and a mutual cancer or varying cancer, right? People that have Lynch syndrome tend to get those get those problems, right? So what's the How did we know that this was a colon cancer? Well as an old person losing weight Blood mixed with their stools, right? And you see that they have very likely iron deficiency anemia, right? You saw the mcv was less than eb So it was a microcetic anemia We saw that the hemoglobin was low, right?

The most common cause of microcetic anemia is iron deficiency anemia Remember the other causes of microcetic anemia is like lead poisoning and anemia of chronic disease sometimes Can also be microcetic and also thalacemia also causes microcetic anemia. Okay, but that's not the main point of discussion today So this person has colon cancer, right? Then where does colon cancer love to go to? Love to go to the liver which makes sense think about it your colon a lot of your colon drains into it the inferior Or supermissenteric veins, right? So since a lot of your colon drains into the inferior supermissenteri veins Believe it or not those things ultimately drain into the hepatic vein and as they drain into the hepatic vein It's gonna ultimately drain into the IVC, right? So it's gonna drain a porovain then hepatic vein then IVC, right? And then you know, so because he kind of goes around the liver a lot You're gonna potentially see this person having a liver amends, right? So that's gonna be the most common area of metastasis For a person that has colorectal cancer, right? So You know colon cancer Um Typically if you suspect that a person has colon cancer you're gonna do some kind of colonoscopy and We do the colorectopy you're gonna see the lesion you're gonna get a tissue biopsy, right? Because getting that tissue biopsy is kind of helpful for helping you decide what kind of Therapy you're gonna do, right?

I usually is about gonna get some kind of C Ts kind of the abdomen as well, right? So again, let's gonna talk about colon cancer workup You're gonna settle for the colonoscopy for the most part when you exams, right? If you're kind of worried about it, you get a colonoscopy Then get a CT scan of the abdomen and pelvis, right? Just to see like whatever meds they need, they need have, right? And typically when people have colon cancer, they're gonna get a bunch of therapies They're gonna get surgery, right? They're gonna get surgery of some sort. They're gonna get surgery Of some sort Um, and then they're also gonna get chemotherapy. They're gonna get chemotherapy You don't need to worry about the chemotherapy regimen At least not for the step two step three level. That's something if you're kind of going to some of these more of you know There's certain residences that kind of worry about this stuff, right?

So like especially the internal medicine folks Yeah, you're probably gonna worry about this stuff quite a bit So you know, these people tend to get bunch of chemotherapy drugs Five FU is kind of a big one And I guess maybe let me throw in a small factor with five FU Right Five FU remember eating hibits thyme, the lead synthase I just kind of figured out what to talk about it because Is one of these drugs that they love to test on step two step three I'm again Every now and then they just toss some pharmacology on these exams and usually gonna be like some common drug Again, don't get me wrong. Handigo for an obscure drug. Yeah, but honestly especially for step three It's gonna be most of these common drugs that people have just kind of forgotten Once the you know cross that boundary for med school In fact, I'm gonna give some quick advice a life lesson based on that point At the end of today's podcast. So don't run away. It's actually gonna be pretty good advice For people that are gonna be taking these exams in the future. I mean that a life lesson at the end But you know, don't forget five FU. How does it work five FU works by inhibiting the enzyme simililate synthase when inhibits amililate synthase Then you can prevent the conversion of deoxyroidin monofosophytes to deoxyfinidin monofosophytes And that's gonna be very helpful for these for these folks, right?

So again with the colon cancer They're gonna get they're gonna get surgery almost always They're gonna be on chemotherapy for sure Right, and then again, you got to deal with the liver problem, right? So the thing is if they just have like a simple meds to the liver right a simple met So you see I use the word met just one liver lesion I just cut out the liver lesion and that's it But if they have like many lesions in the liver that's not good news, right? That's basically if you see like multiple liver meds, right? Meds so multiple, right? And meds Multiple right you see multiple meds. That's not good People don't don't have a that they're probably not gonna do very well on unfortunately, so Just gonna keep that on the back of your mind as you're as you're studying for your for your exams Keep that back of your mind as you're studying for your exams. Okay Um, and again, this is a step just a therapy review. So I'm gonna talk about the step one related things here Um, we're not really gonna go into going to that So I think I should go ahead and stop here Um, this is going on for almost 25 minutes now. I like to keep these rapid reviews short So it's something that listen to when you have like a small bite of time or whatever So again, I hope for review courses for all the US Emily exams Um, the courses offer that you know, I have a course for step one specifically Is a 25 hour course is actually coming up pretty soon.

It's coming up like in the second week of January It's for step one or people taking step two step three to have like awful step one foundations And then um, I have a step two class. I have a 20 hour step two step three class Actually, I have one coming up in December. I'm just coming up. I believe in the third week in December I'm all these courses over zoom and then you know, I have um A 100 hour step two step three school is taking place next year um It's a huge massive time commitment What is like an extremely extremely comprehensive class again I've made separate podcasts on these things. We can kind of check them out on your on your own time and then um for step one to step three out for a 20 hour test Taking strategies class for the NBA means I offer a four hour bio stats class. I have a five hour social sciences and ethics class Um, again all these classes over zoom if you interest they should be an email. I'll use some more information And also these these classes are not lectures right so if you spend expecting lectures Uh, then you should feel certainly should not be attending these classes and these classes are Almost exclusively all scenarios scenarios scenarios scenarios and these scenarios are very helpful Uh, because when it kind of sets your brain in an exam taking mindset What also shows you how the information will be tested and again I'm not just gonna be throwing facts at you.

I'm gonna be discussing pathophase if you've listened to my podcast You understand how I teach um that's how I teach and we also devote a lot of time for questions about one sixth of the total cost time Spend answering people's questions. So again, and this lesson over so you can attend it from literally anywhere in the world And then I have a bunch of helpful charts that people use for last minute reviews well before the exam. So um So for those courses and then I have this podcast on the major apps apple google Spotify Have a You Tube channel divine intervention. You're sending podcasts and videos And then I also have another website called divine intervention life lessons calm And people said many people emailed me that wow divine I love your life lessons So I figured out I'll make another website um divine intervention life lessons calm There's actually an Apple podcast associated with it all the divine intervention life lessons podcast and many people From biblical perspective. I try to put like two podcasts a week I believe we have like 231 episodes right now actually so Okay, so let's go to the life lesson.

I have right so this life lesson all kind of came from this then I said On the fact that wait see if you If you you know if you're taking step three you notice that every now and then the The usually just present like the common drops on the exams right but the thing is most of most people once they crossed That boundary from med school to Residency and they forgot in all these things even things like vancomaic and they're like man. How does vancomaic and work again? Right, I know you may say oh divine there's no way. I will always remember how vancomaic and works Until you start residency and you're like wait vanquat right so here's the thing people don't recognize It's amazing and I've seen this so many times. It's amazing how profound Knowledge atrophy kicks in when you're not in constant review mode This is something that happens a lot with residents. You see like all the stuff These may be people that even go to 70s on their step two And now they just just have absolutely like very little knowledge right so What's the life less in here the life less in here is if you want to keep so actually there two life less in here if you want to keep something in your mind I need to keep using it in some way That's the truth.

I don't keep something you're wanting to keep using it in some way Either you're teaching it or you're thinking it or you're reviewing it or something in some way shape or form But I'm nothing I want to say is it's always important to Get things done as early as possible In fact, that's probably the main life less in here be an early door Right, you can do something you know one of two times you can do it earlier. You can do it lead The thing is when you do something lead You're probably not going to do it as well and you're going to suffer while you're doing that thing You're going to put in way more effort while you're doing that thing right many people wait I've seen this problem so many times you see people They wait until their second year of residency or their third year of residency to take step three by then They're forgetting everything they learned in Med school or at least a good chunk of it They've forgotten a lot of it and then they now have to sweat Sopper struggle as they are prepared for step three they are putting in way more time than is necessary Because they've just forgotten everything. So it's almost like they're learning all these things Fresh straight up right Don't leave till tomorrow what what you can do today right don't leave till your second year of residency What you can do in your first year of residency right?

I've literally seen the story play out so many times you see people They take step three they keep feeling it feeling feeling in residency And then after they failed it enough times the program is then like you know what we're gonna Kick you out and then they get kicked out of residency And then think about it imagine how horrible that is to put in all this work study for all these USML Es And then just because of something that is almost like easily avoidable problem You get kicked out of residency Right, so don't don't be that kind of person right or you go on that radar of your program director or You then start going to some clinical competency committee or some Whatever committee that they they have all these ccc But they just put all these committees in residency, right? So you don't want to be under those things because I know it may sound like I'm blabbing but I promise you this stuff is kind of important for your future When you be going that the spot spot lighting residency is usually not a good thing I'm gonna tell you that right now Resonance is one of those places where you don't want people in your business, right? Once you're going to the spotlight. Oh my goodness.

You're gonna be in so much You're not basically like when Stuff I'm fuck off if they are looking at you as a person that failed an exam Every little thing you do that normally they would overlook it becomes heavily heavily heavily magnified heavily heavily heavily Magnified heavily heavily heavily magnified Right, so like if for example, oh wow something that most other residents do and it's not a big deal For you that has filled a USMLE exam a step three exam in residency It becomes a big deal because they start thinking that you made that mistake because your knowledge is awful Again, you see why you're putting on stick it in on this I promise you this stuff I hope that you're not in a bad situation. We have to remember this advice in the future, right? But just do things early like I remember for me once I graduated from med school I got it like me I took my step three in July of that same year. Just get it out of the way So you don't have to worry about it again And the thing is why does it make sense to take in fact honestly, I'm almost gonna make a podcast on When to take step three. I think it'll be a smart smart podcast to make I just think it's gonna help a lot of people because here's the thing When you start residency People have very few expectations of you they almost feel like this person is a fresh fresh Newborn resident.

They don't know they are left from the right in the hospital So if you make them with these people just chalk it up to ah he doesn't know better or she doesn't know better, right? so That's a good time to study for antics step three when People are still treating you with a lot of benefit of doubt But as you go along in residency become a second year third year It kind of expects you to know a lot right? So at that point and you you have more responsibilities You're responsible for more you have all these juniors you got to deal with right? You have all these med students you've got a cater to So if at that point you're you're kind of struggling right and you don't have all this time to study Then that increases your risk of failing the exam So honestly, I don't want you to be in this situation. So please like Whatever you can do if you know that man there's something I can just do to be and get it over with just get it done Right, like you see residents they have all these modules that supposed to complete yes at these modules and things annoying Yeah, they're annoying right but in the put a timely bit on it Right and then you wait till the last minute or you don't get it done and then the program director gets angry at you And as they get angry at you you're wondering why they get angry at me Well, you could have just done the right thing. Don't put yourself on anyones radar.

Don't put yourself on anyones radar Right, so in fact, I think this podcast on this is I'm saying this life lesson. I'm gonna stop here But I think I'm gonna do a podcast on a residency etiquette Resoncated kid. I think it's one of these things that's actually gonna help Pretty large number of of people. So that'll be a future podcast god willing and we'll see where that takes Okay, so thank you for listening to me today again My apologies for kind of rambling at the end, but I promise you this advice is so important I don't have just seen too many cases. I see so many of these every single year because people reach out to me all the time I've seen so many cases of this every single year. You see some resident for some ridiculous reason This is not getting in trouble with your program, right? You don't have to be in this situation if you just kind of play your cards Right, so until next time Bye for now. God bless you

Practice questions — USMLE style

Question 1 — Electrolyte/Oncology

A 45-year-old female is diagnosed with aggressive lymphoma and begins receiving intensive chemotherapy. Within 72 hours of starting therapy, she develops acute kidney injury, profound muscle weakness, and her laboratory values reveal a potassium level of 6.8 mEq/L, phosphate level of 15 mg/dL (normal range: 0.8–1.5 mg/dL), creatinine of 3.5 mg/dL, and calcium of 7.2 mg/dL (normal range: 8.5–10.5 mg/dL). Which condition is most likely responsible for this constellation of findings?

  • A) Acute tubular necrosis secondary to nephrotoxin exposure
  • B) Hypoparathyroidism due to chemotherapy-induced damage
  • C) Hyperkalemic metabolic acidosis with renal failure
  • D) Tumor Lysis Syndrome (TLS)

Answer: D. The combination of hyperkalemia, hyperphosphatemia, hypocalcemia, and acute kidney injury following the lysis of numerous malignant cells is classic for Tumor Lysis Syndrome (TLS). TLS occurs because massive cell death releases intracellular contents into the bloodstream. Specifically, high phosphate binds with serum calcium, causing hypocalcemia; potassium leaks out, causing hyperkalemia; and the breakdown of nucleic acids leads to metabolic acidosis and kidney failure.

Question 2 — Neurology/Oncology

A 65-year-old male with a history of prostate cancer presents to the emergency department with progressively worsening bilateral lower extremity weakness, saddle anesthesia, and urinary retention over the last week. Physical examination reveals diminished reflexes in the legs. Which intervention should be initiated immediately upon suspicion of spinal cord compression (SCC)?

  • A) High-dose intravenous immunoglobulin (IVIG)
  • B) Intravenous steroids (e.g., Methylprednisolone)
  • C) Immediate surgical decompression via laminectomy
  • D) Urgent lumbar puncture to rule out infection

Answer: B. In the setting of suspected spinal cord compression due to malignancy, the immediate priority is to reduce inflammation and edema around the neural structures. High-dose intravenous corticosteroids (such as methylprednisolone or dexamethasone) are the standard initial treatment to stabilize the cord and prevent irreversible neurological damage. While MRI is necessary for diagnosis, steroids are the first acute intervention.

Question 3 — Vascular/Oncology

A 50-year-old man presents with facial swelling, neck fullness, and signs of venous congestion in his upper extremities. Physical examination reveals jugular venous distention (JVD) that appears disproportionate to his cardiac status. Initial imaging suggests a mass encasing the superior vena cava (SVC). Given his history of aggressive lymphoma, which malignancy is the most likely cause of this SVC syndrome?

  • A) Squamous cell carcinoma originating in the lung
  • B) Primary mediastinal thymoma
  • C) Lymphoma
  • D) Metastatic adenocarcinoma from colorectal cancer

Answer: C. While lung cancer is the classic cause of SVC syndrome (due to its location), lymphoma is a critical differential diagnosis, especially when considering younger patients or those with known hematologic malignancies. The concept tested is that any process encasing the superior vena cava can cause SVC syndrome, and aggressive lymphomas are common causes in this context.

Question 4 — Gastroenterology/Oncology

A 75-year-old man presents with a three-month history of unexplained weight loss, iron deficiency anemia (MCV < 80 fL), and hematochezia (bright red blood mixed with stool). Laboratory workup suggests colorectal malignancy. Based on the anatomical drainage patterns of the colon, what is the most common site for distant metastasis from this primary tumor?

  • A) Lungs
  • B) Bone marrow
  • C) Liver
  • D) Adrenal glands

Answer: C. The majority of the colonic vasculature drains into the inferior and superior mesenteric veins, which ultimately drain into the hepatic portal system and subsequently the IVC. Because the liver is directly in the path of this rich venous drainage, it is the most common site for distant metastasis from colorectal cancer.

Quick fire review

What are the classic electrolyte abnormalities seen in Tumor Lysis Syndrome (TLS)?

Hyperkalemia, hyperphosphatemia, hypocalcemia, and metabolic acidosis.

What is the first-line treatment for suspected spinal cord compression?

High-dose intravenous corticosteroids (e.g., Dexamethasone).

Which imaging study is considered the gold standard for diagnosing spinal cord compression?

MRI (Magnetic Resonance Imaging).

In SVC syndrome, what anatomical structure is physically obstructed?

The Superior Vena Cava (SVC).

What mechanism causes hyperphosphatemia in TLS?

Massive cell death releases phosphate from intracellular ATP stores.

Name two specific drugs used to prevent hyperuricemia in TLS.

Allopurinol or Rasburicase (or PEG).

What is the primary cause of hypocalcemia and hyperphosphatemia in Tumor Lysis Syndrome?

Phosphate binds with calcium, leading to low ionized calcium levels.

Which malignancy can cause SVC syndrome besides lung cancer?

Lymphoma or aggressive lymphomas (e.g., Hodgkin's).

What is the most common site of metastasis for colorectal cancer due to venous drainage patterns?

The liver.

What class of drugs are Rasburicase and Allopurinol, and what do they inhibit?

Xanthine oxidase inhibitors; they prevent the overproduction of uric acid.

If a patient presents with signs of spinal cord compression, what is the immediate priority before definitive treatment (radiation/surgery)?

Administering IV steroids to reduce inflammation and edema.

Quick recall / Anki-style questions

What is the primary cause of hypocalcemia and hyperphosphatemia in Tumor Lysis Syndrome?

Phosphate binds with calcium, leading to low ionized calcium levels.

Which malignancy can cause SVC syndrome besides lung cancer?

Lymphoma or aggressive lymphomas (e.g., Hodgkin's).

What is the most common site of metastasis for colorectal cancer due to venous drainage patterns?

The liver.

What class of drugs are Rasburicase and Allopurinol, and what do they inhibit?

Xanthine oxidase inhibitors; they prevent the overproduction of uric acid.

If a patient presents with signs of spinal cord compression, what is the immediate priority before definitive treatment (radiation/surgery)?

Administering IV steroids to reduce inflammation and edema.