Peritoneal Tuberculosis in an Immunocompetent Patient With Findings of Chronic Liver Disease and Peritoneal Carcinomatosis

Abstract

Peritoneal tuberculosis (PT) accounts for 1-2% of all tuberculosis cases. Diagnosis of PT can be challenging due to non-specific symptoms, insidious onset, and variable imaging findings. We present a case of PT presenting with ascites and imaging studies suggestive of chronic liver disease (CLD), and peritoneal carcinomatosis.A 48-year-old man presented to our clinic with complaints of increased abdominal girth, weight loss, and night sweats for the past 3 months. Physical exam revealed soft and distended abdomen with shifting dullness. Laboratory tests showed a mild anemia of Hb at 13.0 g/dL (13.1-17.2) and ESR at 34 mm/h (0-15). Abdominal ultrasound (US) revealed the presence of free abdominal fluid, and diffuse heterogenous granular liver parenchyma supporting the diagnosis of CLD. His liver tests were within normal ranges. Ascitic fluid analysis revealed serum ascites albumin gradient (SAAG) of 0.2 g/dL, WBCs of 1.70 × 103 cells/dL (91.8% lymphocytes). Ascitic fluid cytology was negative for malignant cells. Ascitic fluid acid-fast bacilli (AFB) test and mycobacterial culture were negative. Adenosine deaminase (ADA) level in ascitic fluid was 108.5 U/L (0-40). Interferon-gamma release assay (IGRA) test was positive. Contrast-enhanced computed tomography (CT) scan revealed normal liver parenchyma, diffuse thickening and nodularity of the peritoneum, and thickening of omentum with omental cake appearance. CT scan was suggestive of peritoneal carcinomatosis. EGD and colonoscopy were unremarkable. With consistent clinical history, SAAG < 1.1, ascitic fluid with lymphocytic predominance, high ADA levels, and positive IGRA, a diagnosis of PT was made. Anti-tuberculosis treatment was initiated, and the patient’s clinical symptoms have improved. CT scan at the end of treatment showed the resolution of ascites and peritoneal findings. Ascites is the most common presenting symptom of PT. High suspicion of PT is important in the setting of ascites of unknown origin. Despite the US findings were suggestive of CLD in this patient, CT scan revealed normal liver findings. Differing PT from peritoneal carcinomatosis might be challenging due to overlapping findings on imaging. Ascitic fluid analysis of SAAG < 1.1, high ADA levels, positive IGRA test should lead towards the diagnosis of PT. AFB and mycobacterial culture of the ascitic fluid may often have low diagnostic yield in PT. Early diagnosis and treatment are important to prevent complications.