Answer and Discussion of Quiz Set: A-001

2.    A patient presented with right lower quadrant pain for three days, and appendectomy was performed. Grossly the appendix was normal, and microscopically few confluent epithelioid granulomas were found in the mucosal lymphoid tissue. Which of the following is NOT likely to be the cause of these granuloma? 

A.  Crohn’s disease

B.  Sarcoidosis

C.  Histoplasma capsulatum

D.  Clostridium difficile

E.  Yersinia

Answer and Discussion: The answer is (D). The diagnosis is granulomatous appendicitis. The etiology of the granuloma includes parasites (schistosomiasis, strongyloidiasis), bacteria (Yersinia, Mycobacterium, actinomyces), fungi (Candida species, Histoplasma capsulatum), Crohn’s disease, sarcoidosis, and foreign body reaction.  Clostridium difficile causes pseudomembranous colitis, not granulomatous appendicitis.