Monday, March 31, 2008


Note the buccal mucosa.

Challenge: On a test, this disease appears with symptoms of fever plus 3C's. What are they?

Image shown under fair use.

Friday, March 28, 2008

Lumpy Jaw

So when I think of "lumpy jaw" I think of Burkitt's lymphoma. But what if the "lumpy jaw" question came with this:

Challenge: What's the causative organism?

Related Questions:
1. This organism is always paired with another organism that looks just like it on gram stain but stains weakly acid fast. What is that organism?
2. What is the organism that causes Burkitt's lymphoma?
3. Sorry, I know this question sucks. What is the chromosomal mutation involved in Burkitt's lymphoma? What is the resulting protein?

Image is shown under fair use.

Wednesday, March 26, 2008

Dubious D's

Here are two separate cases.

A chronic alcoholic stumbles into your emergency room, but as you take a history, you realize he has no idea who he is or where he is. He can't do serial 7's, doesn't remember any of three objects after a few minutes, can't copy a figure. His MMSE is pretty bad. On exam, you notice this:

He suddenly says, "Oh I remember what's been bothering me. I have to keep going to the bathroom. Must be something I ate."

Challenge 1: Is it something he ate? Or something he didn't eat? What's the diagnosis?

-You can see the changing posture of this boy over time. On exam, you notice he has huge calves. These days, though, he has to use his arms to push himself up from a sitting position.

Challenge 2: What's the mutated gene?

First image is in the public domain, second image shown under fair use.

Monday, March 24, 2008

I Never Really Learned This Disease

So I'm reviewing it now. This is not infectious.

Challenge: This disease is associated with a specific histopathological finding. What is it?

Images shown under fair use.

Friday, March 21, 2008


Most cases of this are discovered in infants and children with stridor and swallowing difficulties. But this MRI is of a woman in her forties with headache. You notice her gait is somewhat clumsy, there is diminished upward gaze, truncal instability, and bilateral increased reflexes.

Challenge: What's the diagnosis?

This image and case are from a website, shown under Fair Use. This is because I couldn't find a great UpToDate article.

Wednesday, March 19, 2008


Interesting, huh? (Try it at home!). Upon further examination, this boy's arm span exceeds his height, he has severe scoliosis, and the lens of his eyes are displaced upward.

Challenge: What's the main cause of morbidity and mortality in these patients?

Related Questions:
1. What's shown on the image?
2. What's the diagnosis?

Image shown under fair use.

Monday, March 17, 2008

Question Stem

You're all fired up to take the USMLE and turn to the first question.

A forty-year old fat fertile female presents with..."

You don't read another word and quickly bubble A.

Challenge: What was the diagnosis?

Friday, March 14, 2008

Neurons That Fire Together, Wire Together

Here's a collection of quick cases.

"Worst headache ever."
Challenge 1: What are you looking at?

Related Questions:
1. What happened?
2. What's the cause?
3. What are the risk factors?
4. What is the initial work-up?

Young adult, low back pain, limited spinal mobility, with acute anterior uveitis.
Challenge 2: This is associated with a specific genotype. What is it?

Fatigue, infection, gingival bleeding.
Challenge 3: Diagnosis?

All images shown under Fair Use.

Wednesday, March 12, 2008

Skin Review

Here's the histology (click to read the labels):
Note the lesions are found on the hand, an often sunlight-exposed area.

Challenge: What is concerning about these lesions?

Images shown under fair use.

Monday, March 10, 2008

Students of Hookers

This was done in Dr. Josephson's BMB Case of the Day, but deserves a rerun for USMLE review.

A 60 year old man presents with sudden, brief, severe stabs of pain affecting the limbs lasting for minutes. He also has an ataxic gait. His pupils are small, do not respond to light, but contract normally to accommodation and convergence.

Challenge: What's the diagnosis?

Friday, March 7, 2008

Star Light, Star...

A six year old girl begins to develop breast buds and menstrual periods. You note ovarian cysts as well as these findings.

Challenge: What's the diagnosis?

First image is in the public domain, second image shown under fair use.

Wednesday, March 5, 2008

Renal Review

Parents bring their 5-year-old son in because they noticed blood in his urine without history of trauma or infection. He is also deaf. The parents say that several other members in the family have this disease too, but they forget what it's called.

Challenge: What is it called?


Hi everyone. This site was never meant to be "high-yield" preparation for the USMLE. Instead, it is a resource to learn more about interesting diseases and practice differential diagnosis.

However, now that it is March (and given the title of the last case), I am going to turn my attention to Step 1 of the Boards. Cases for this month will, for the most part, focus on information that may be useful for the big quiz. I think they will mostly be taken from the "classic findings" section of First Aid for the USMLE Step 1.

Please note that previous cases are actually pretty good for Boards studying; a lot of things mentioned in First Aid I've already done in previous cases. Those will be labeled as "USMLE Classic Findings."


Monday, March 3, 2008

Boards Prep

A 70 year old European coal miner comes to you with joint pain and trouble breathing. You notice his hands:

On CXR, you find multiple peripheral basilar nodules. He is PPD and HIV negative. You rule out the most common etiology of multiple pulmonary nodules (which you learned for Boards): metastatic solid organ malignancy, Non-Hodgkin's lymphoma, Kaposi sarcoma, multiple bacterial abscesses, septic emboli, fungi (histoplasmosis, coccidioidomycosis, aspergillosis, cryptococcus), flukes (Paragnomius westermani), Wegener's granulomatosis, and AV malformation. Histology of one of those nodules would show the following:

Interesting. You note the central necrosis. This is an odd association between two diseases, one reflecting the joint pain and one reflecting the pulmonary nodules.

Challenge: What is this syndrome called?

Both images shown under fair use.
Case idea and title contributed by Alex Penn.