Answer of July 2006

Clinical History:

A 40 year old lady who had been on chemotherapy for non-small cell lung carcinoma presented with abdominal pain, diarrhoea and fever.

Diagnosis:

Pseudomembranous colitis

Discussion:

Contrast-enhanced CT scan of the abdomen demonstrated marked circumferential thickening of colon wall. The enhancing mucosa and the thickened hypodense submucosa at the ascending colon formed a 'target' appearance. The whole colon was involved and there were presence of pericolonic fluid and ascites. Given the patient's clinical history, these features were highly suggestive of pseudomembranous colitis (PMC). This diagnosis was confirmed by a positive stool culture for C difficile and presence C difficile cytotoxin in stool.