Peritoneal Tuberculosis in a Female Patient Mimicking Peritoneal Carcinomatosis: A Case Report

Peritoneal tuberculosis (PTB) is a rare extrapulmonary disease. The clinical and radiological findings closely resemble those of peritoneal carcinomatosis, leading to diagnostic confusion. Herein, we present a case of PTB in a patient who underwent general surgery with a preliminary diagnosis of peritoneal carcinomatosis. A 47-year-old woman presented with abdominal pain for three months. Abdominal evaluation revealed generalized tenderness and mild defenses. Contrast-enhanced abdominal CT demonstrated free fluid in the peritoneal cavity, especially in the lower abdomen, irregular infiltration of the anterior intraperitoneal fat tissue, and many small nodular lesions on the peritoneal and omental surfaces. The CA-125 level (758.3 U/mL) was markedly elevated. Gynecologic assessment did not reveal any evidence of malignancy. Colonoscopy revealed sigmoid diverticulosis. Upper endoscopy revealed erosive antral gastritis. Due to the persistent diagnostic uncertainty, diagnostic laparoscopy was performed. Biopsies of the omentum and peritoneum were obtained. Histopathological examination revealed widespread granulomatous inflammation with epithelioid histiocytes and Langhans-type giant cells. The QuantiFERON-TB Gold test results were positive. The patient was evaluated in consultation with the Department of Infectious Diseases. Anti-tuberculosis therapy was initiated immediately and has been ongoing without any adverse events for seven months.