Thursday, January 31, 2013


A 50 year old African American presents with an embolic stroke. During the stroke workup, he is found to have intraatrial thrombi but is in normal sinus rhythm. The echocardiogram shows LV thickening and atrial thrombi.

Over the next year, he develops lower extremity edema, decreased exercise tolerance, and elevated liver enzymes. He has some chest pain, but an angiogram is negative for coronary artery disease. EKG shows low voltage in the limb leads. A repeat echo shows diastolic dysfunction, a small LV cavity, biatrial enlargement, and RV dilatation. The myocardium is easily seen and described as "granular and sparkling."

A year later, he develops exertional syncope. Two months later, he has sudden cardiac death. On autopsy, the heart is large and rubbery. The histopathology is shown below. The left slide is stained with H&E. The right slide is stained with alcian blue.

A slide of normal myocardium is shown below for comparison:

Challenge: What's your diagnosis?

Images shown under Fair Use.

Monday, January 28, 2013

Truth Serum

A patient is referred to your interventional neurology practice for pre-operative assessment prior to temporal lobe resection. Other than a longstanding history of refractory seizures, the patient is healthy. You place a percutaneous transfemoral catheter under local anesthesia into the femoral artery. You guide the catheter into the left carotid artery. You inject 100mg of truth serum, shown above. Then, you ask the patient to speak, repeat sentences, answer questions, and memorize a series of pictures. Afterwards, you repeat the procedure with the right carotid artery.

Challenge: What procedure did you just perform?

Image shown under Creative Commons Attribution Share-Alike License.

Thursday, January 24, 2013


A 3 year old is brought in for dry, scaling skin. Interestingly, the father has this skin problem too, though it has been undiagnosed. "I always thought it was just atopic dermatitis," he says. The father says that his got significantly worse at puberty. It becomes worse with dry weather and is especially pronounced in winter. Most of the lesions are on the shins, back, and heels. They do not occur in flexural areas.

Challenge: What do father and son have?

Image is in the public domain.

Monday, January 21, 2013


A 70 year old gentleman is struck by a car while walking across the street. Upon arrival to the trauma bay, he is tachycardic, tachypneic, hypotensive, and altered. He is in a great amount of pain around his hips, back, and lower abdomen. On examination, you note blood at the penile meatus. You obtain a plain AP X-ray:

Challenge: What's your diagnosis?

Image shown under GNU Free Documentation License.

Thursday, January 17, 2013


A 25 year old incarcerated gentleman presents with dysuria and urethral discharge. The discharge is watery, and microscopic examination is shown above. Although diagnostic tests include culture, direct immunofluorescence, ELISA, and nucleic acid amplification techniques (NAAT), you choose to do NAAT because it can be performed on a urine specimen and has the highest sensitivity and specificity.

Challenge: What's your diagnosis?

Image is in the public domain.

Monday, January 14, 2013


You work in the laboratory. You get these lab values for a 30 year old patient. The reference range for normal is in parentheses:

Hemoglobin (g/dL): 10.5 (12-15.8)
Erythropoietin (U/L): 50 (4-27)
Ferritin (ng/mL): 200 (10-150)
Serum folate (ng/mL): 20 (5.4-18)
WBC (x10^3/mm3): 12 (3.5-9.1)
D-dimer (ug/mL): 1.0 (0.22-0.74)
Albumin (g/dL): 3.0 (4.1-5.3)
Bicarbonate (mmol/L): 21 (22-30)
Lactate (U/L): 300 (115-221)
Aldosterone (ng/dL): 50 (2-9)
Cortisol (ug/dL): 30 (0-25)
Parathyroid hormone-related protein: 2.0 (<1 .3=".3" div="div">
Renin (ng/mL/h): 50 (0.3-9)
Prolactin (ng/mL): 200 (0-20)
Testosterone (ng/dL): 150 (6-86)

Challenge: Tell me about the patient.

Image shown under Creative Commons Attribution Share-Alike License, from Wikipedia.

Thursday, January 10, 2013


A patient comes to your genetics clinic with a very rare autosomal dominant disease with incomplete penetrance. The patient's onset of symptoms was at 3 years. He has recurrent fevers without evidence of any viral or bacterial infection. The fevers are not cyclical, last five days to two weeks, and have no discernible trigger. Over time, the patient realizes that the attacks are accompanied by focal migratory myalgias, conjunctivitis, periorbital edema, abdominal pain, a monoarticular arthritis, and an erythematous patchy rash that spreads distally down an extremity over time. ESR and CRP spike during these attacks but remain modestly elevated during asymptomatic periods. RF and ANA are negative. You refer the patient to nephrology because 15% of patients develop secondary amyloidosis.

Challenge: What's the diagnosis?

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Monday, January 7, 2013


A 65 year old patient presents with weakness in the arms and legs including difficulty with fine motor control of his fingers. He has neck pain, numbness, and tingling that radiates to the arms. When he enters your office, you notice an odd walk: he has high steps and stamps down with his heel followed by the sole of his foot. The gait is slightly wide-based. His wife says his walk becomes a lot worse in the dark.

Challenge: What's your diagnosis?

Image shown under Fair Use.

Thursday, January 3, 2013

The Shining Moon

A drunk patient is brought in, complaining of visual blurring. He boards in the emergency department while he metabolizes to freedom, but as time goes on, he complains of central scotomata and then blindness. His mental status worsens with coma, and then a seizure which breaks on its own. Exam shows an afferent pupillary defect. You grab the ophthalmology resident and when he takes a look, he notes mydriasis, a retinal sheen, and hyperemia of the optic disc. CT scan of the head is normal. Labs show a bicarb level of 7 mEq/L with a normal lactate. Glucose is normal and there are no ketones in the urine. Tylenol and salicylate levels are normal. EKG is normal. You decide to give him IV ethanol (an unusual request, but the pharmacy gets to work compounding it).

Challenge: What's the most likely diagnosis?

Image is in the public domain.