Peritoneal Tuberculosis Mimicking Peritoneal Carcinomatosis

A 67-year-old male presented with fatigue, abdominal pain, and 30-pound weight loss over 3 months. Computerized tomography (CT) abdomen displayed ascites with thickening and enhancement of the peritoneum and mottled nodular appearing as soft tissue consistent with omental caking worrisome for peritoneal carcinomatosis. A paracentesis revealed white blood cell count of 2,500 with 98% lymphocytes and serum ascites albumin gradient of 0.9 g/L. No acid-fast bacilli were seen by microscopic exam and culture was negative. Purified protein derivative skin test (PPD) was negative and CXR did not reveal any infiltrates. Esophagogastroduodenoscopy (EGD) and colonoscopy were unrevealing. The patient underwent exploratory laparotomy with round ligament and peritoneal biopsies that revealed numerous necrotizing granulomas. Acid-fast bacteria Ziehl-Neelsen stain (AFB) of the biopsy specimen revealed single acid-fast bacilli. Treatment for M. tuberculosis was initiated and final culture revealed that mycobacterium tuberculosis was sensitive to Isoniazid, Rifampin, Ethambutol, and Pyrazinamide. After 6 months of treatment, the ascites and peritoneal carcinomatosis resolved.