Monday, January 19, 2015

Flesh Bladder

There are two distinct manifestations of this disease.

The first is seen in a man who eats undercooked beef or pork. After one or two days, he develops nausea, vomiting, abdominal pain, bloating, and watery diarrhea. Symptoms are self-limiting and resolve within 36 hours.

The second is a patient who traveled to rural Malaysia and encountered snakes. After about a week and a half to two weeks, he develops fevers to 39 C, rigors, myalgias, and headaches. This becomes a relapsing-remitting course with episodes lasting 4-5 days. You note myositis with muscle tenderness and muscle swelling, especially in the muscles of mastication, calf muscles, and superficial back muscles. Here's a T2-weighted short tau inversion recovery (STIR) MRI sequence:

In both cases, patients have eosinophilia and lymphocytosis. The other cell lines are fine. AST, ALT, and GGT are elevated moderately (less than twice the upper limit of normal) and CK is moderately elevated. A biopsy is shown below:

Challenge: What's the diagnosis?

Both images shown under Fair Use.


RaH said...

I found the answer while reading this paper..
this is my guess:
Sarcocystis nesbitti Causes Acute, Relapsing Febrile Myositis with a High Attack Rate: Description of a Large Outbreak of Muscular Sarcocystosis in Pangkor Island, Malaysia, 2012

Craig Chen said...

wow - yeah! i'm definitely impressed. i had not heard of this disease until i started researching for this case of the day.
Flesh Bladder

This is sarcocystosis, which comes from the Greek sarx for flesh and kystis for bladder. Sarcocystosis is a zoonotic infection by a protozoan parasite Sarcocystis. The MRI shows myositis of the muscles of mastication. The biopsy shows a single sarcocyst within a muscle fiber, Endovascular inflammation is shown in the perimysium and endomysium.

Source: UpToDate.