Monday, December 14, 2009


A 20 year old man presents with left lower back and flank pain over the last few weeks. He's also noted fever, a limp, lack of appetite, and weight loss. He has recently immigrated from sub-Saharan Africa and has not been receiving medical care. He denies alcohol, smoking, or IV drug use.

On exam, he has severe pain with extension of the hip and limited hip movement. He prefers to be in a position with hip flexion and lumbar lordosis. Laboratory studies show WBC 12,000/mL, Hgb 10 g/L, elevated ESR and CRP. A CT is shown below:

The white arrow indicates where aspiration was done. A routine gram stain and bacterial culture were sent but they are negative. Routine bacterial cultures of the blood are negative as well.

Challenge: What's the diagnosis and what is the cause?

Image is shown under Fair Use.


tree said...

Hmm that looks like an abscess... hmm that looks like the psoas... psoas abscess! Yesssssss.

Cause: Tuberculosis/Pott's

Suheil said...

TB Pyelonephritis? PCR for TB, ZN stain of the Aspirate with Culture on LJ medium to confirm?
Fingers really crossed on this one..

Craig Chen said...

haha yes, its tb causing a psoas abscess.

This is a psoas abscess; the bacteriology is most often Staph aureus and Mycobacterium tuberculosis in endemic areas (sub-Saharan Africa, India, China, Southeast Asia, Micronesia). With negative cultures and a history of living in an endemic area, TB must be suspected.

Sources: UpToDate; "Extrapulmonary Tuberculosis: An Overview" by Golden and Vikram from

Suheil said...

damn! :( dunno wat i was thinking! atleast i got the TB part right...