Monday, June 29, 2009


You're doing lab medicine and get the two blood smears shown above. Your attending tells the team to order a historically important test. The team gives the patient 2mcg oral radio-labeled drug A and 1000 mcg intramuscular non-labeled A. Urine is collected and the excretion of radio-labeled A is low (<8% of the administered dose).

The team then repeats this test but also gives oral drug B along with the oral drug A, followed by the intramuscular non-labeled A. The urine collection now shows normal excretion of the radio-labeled molecule A (8-35%).

Challenge: What is the diagnosis and how is the coin shown above related?

First image is in the public domain (photoshopped by me), second and third images shown under Fair Use.

Friday, June 26, 2009


An 18 year old man gets into a car accident and requires blood transfusion. When he gets transfused with the first unit, he experiences anaphylaxis. He has never had a blood transfusion in the past, but testing shows IgG antibodies against IgA. The only other thing he notes is that as a child, he had recurrent upper and lower respiratory tract infections with bacteria like S. pneumoniae and H. influenza.

Challenge: What's the diagnosis here?

Wednesday, June 24, 2009

Collagen IV Mutation

A 30 year old woman was recently diagnosed by her family physician with a urinary tract infection. The urinalysis at the time showed microscopic hematuria. At the following visit 3 months later, another urinalysis showed microscopic hematuria with no other abnormalities. Urinary protein excretion and blood pressures are normal. The patient is asymptomatic; she has never seen blood in her urine. She notes that several family members have positive tests for microscopic hematuria but no symptoms and no renal failure. Renal biopsy here is not indicated, but if you did a renal biopsy, you would see the following:

The top is normal; the bottom would be the patient's EM. Light microscopy is normal.

Challenge: Diagnosis?

Image shown under fair use.

Monday, June 22, 2009

Prenatal Diagnosis

A 25 year old Caucasian woman (G1P0) with epilepsy presents to prenatal diagnosis clinic because a routine maternal serum AFP screen at 16 weeks showed a value 2.5 multiples of the median. An ultrasound confirms the diagnosis.

Challenge: To prevent this in the future, you would recommend that she take what drug? You would recommend that she stop what drug?

Image is in the public domain.

Friday, June 19, 2009

Vital Signs

I think this is a good case!

A 30 year old Asian woman presents to your clinic complaining of fatigue, weight loss, and low-grade fever. You send off some basic labs, reassure her, and send her home. The lab results show a normochromic normocytic anemia but are otherwise unrevealing. You put her on iron.

She presents a year later and you're surprised because now she looks sick. She complains about arm and leg pain with use. Sometimes when she uses her arms while cleaning, she gets dizzy. You get a "pan-positive review of systems"; she's noticed arthralgias, myalgias, chest pain, dyspnea, vertigo, orthostasis, headaches, abdominal pain, and diarrhea.

On physical exam, she's febrile to 38.4. Her pressures are 110/60 in her left arm, 95/50 on her right arm, and 150/90 with a wide cuff on her right thigh. The nurse had trouble taking the pulse. You feel her extremities and they're surprisingly cold. Her pulse is weak and asymmetric. You hear bruits over the subclavian arteries, brachial arteries, carotid arteries, and abdominal vessels.

Lab results show a normal white count, a normocytic normochromic anemia, elevated ESR, elevated CRP, hypoalbuminemia.

Challenge: Wow, the pressures are like reverse-coarctation! What's going on?

Wednesday, June 17, 2009

A Dime a Dozen

This CT is from a woman who has had two C-sections in the past now presenting with abdominal distension, vomiting, and crampy periumbilical pain every five minutes. She says she hasn't passed flatus in a while.

Challenge: What's the diagnosis?

Image is shown under fair use.

Monday, June 15, 2009

Ancient Egyptians Ate Liver

You decide to do an international rotation in Africa where you see a malnourished patient in clinic with poor bone growth, non-specific skin findings, a mildly immunocompromised state, and the eye finding above. He says he has poor vision at night.

Challenge: The ancient Egyptians knew about this disease and treated it with eating liver. What is it?

Image shown under fair use.

Friday, June 12, 2009

Move Stupid

A 70 year old woman is brought in by her caretaker for decreased mental status. Her caretaker noted lethargy and confusion at home, but now she is more obtunded. Her caretaker says that toxins are impossible and that there have been no new drugs. She has no liver, kidney, or psychiatric disease and is not a drinker. There was no seizure activity or trauma. Her past medical history includes a head and neck cancer treated with radiation and a cardiac arrhythmia controlled on amiodarone.

On exam, temperature is 34 degrees Celsius, heart rate is 50, blood pressure is 90/40, respiratory rate is 10, oxygen saturation is 97% on room air. Labs show a low sodium and low sugar. BUN, creatinine, calcium, magnesium, CBC, lactate, and cortisol are all normal. RPR, blood cultures, U/A, and CXR are negative. An LP shows only modest elevation of protein, not consistent with a CNS infection. Scans of the head are negative for structural abnormalities or stroke. B12, thiamine, and glucose are given, but do not help. She is rewarmed and her vital signs are corrected, but she still has persistent altered mental status.

Challenge: You've ruled out most of the causes of coma; what's left?

Wednesday, June 10, 2009


This female infant was born at home at 36 weeks gestation to a 40 year old mother. Parents declined routine newborn screening. Like the vast majority of infants with this disease, she did not have any clinical manifestations at birth because the defect is compensated by maternal placental transfer of the deficient molecule, shown below.She's now six weeks old and still has jaundice. She also has a bit of lethargy, a hoarse cry, poor feeding, macroglossia, an umbilical hernia, large fontanels, and hypotonia.

Challenge: What's the diagnosis?

Both images are in the public domain.

Monday, June 8, 2009

Queen of Denmark

In my leisurely late night reading, I came across a 2007 article in the Journal of Medical Biography describing this 16th century celebrity and an eponymous sign named after her. Apparently, people with "abbreviated eyebrows" as shown in this portrait may have a certain disease. The sign was misnamed as this queen did not have the disease, but if she did, she might complain of the following symptoms: fatigue, slow movement, slow speech, constipation, and weight gain. Her exam might reveal delayed deep tendon reflexes, bradycardia, dry skin, and coarse hair.

Challenge: What disease am I talking about?

Image is in the public domain.

Friday, June 5, 2009


This child complained about gradual onset sore throat, malaise, and low grade fever. The gram stain is shown below.

Challenge: What is the organism?

First image shown under Fair Use, second image is in the public domain.

Wednesday, June 3, 2009

Name That Car

A 35 year old G5P4 Asian woman with 3 prior C-sections at 34 weeks gestation presents with painless vaginal bleeding. She has no contractions, no pain, no loss of fluid, and fetal movement is present.

Challenge: You get sterile gloves for your digital vaginal exam when your resident comes up to you and says, "Stop! She might have a..." What?

Image is in the public domain.

Monday, June 1, 2009


I know this is a hard picture to see but we're looking at that nodular red-purple skin lesion in this gentleman. He presented to his primary care physician complaining of fever, chills, malaise, headache, anorexia, and weight loss. Concerned about these constitutional symptoms, the primary care doctor sent off a bunch of labs and found that the patient was HIV positive with CD4 count 95 cells/mm3. He was then referred to you for this odd skin lesion.

These lesions typically first develop as small red to purple papules that can expand to large pedunculated lesions or nodules that may be friable. Though the surface starts off smooth, it can erode and ulcerate. Trauma may cause lesions to bleed profusely. This is the only lesion noted on this gentleman.

Challenge: Well, you think, this is probably Kaposi's sarcoma, until the primary care doctor calls you and says the blood cultures came back positive with what organism? (Meow)

Image is shown under fair use.