Peritoneal tuberculosis mimicking carcinomatous ascites in a child living in a low prevalence country: a case report

BACKGROUND: Ascites can develop as a consequence of a number of diseases in childhood. Despite chronic liver disease is the most common cause, several conditions can lead to ascites also in the absence of liver dysfunction. As non-cirrhotic ascites shows a high degree of overlapping sign and symptoms it is still a challenge for physicians. CASE PRESENTATION: A 8-year-old Caucasian girl was referred for fever, vomit and diarrhea occurred over the past few weeks. Physical examination showed timpanitic distension of the abdomen with marked tenderness and increased abdominal wall rigidity. Abdominal imaging showed diffuse ascites and thickened omentum and bowel wall. Blood tests showed increased C- reactive protein levels and decreased lymphocyte count. Specific treatment for inflammatory bowel disease was started. Persisting of ascites required additional investigations. Positive tuberculin skin test and Interferon Gamma release assay (IGRA) as well as increased Ca125 serum concentrations were found. Computed tomography scan showed mediastinal and mesenteric adenopathies and diffuse smooth thickening of the omentum with significant enhancement (omental cake-like). Ascitic fluid analysis revealed high leucocytes and protein levels. Presumptive diagnosis of peritoneal tuberculosis (PTB) was made. Antituberculous treatment resulted in the resolution of ascites and normalization of lymphocyte count and Ca125 serum concentrations. CONCLUSIONS: PTB is still possible in low-prevalence countries. As it is a great mimicker of other abdominal pathology whose treatment might worsen tuberculosis progression, clinical suspicion and adequate screening are required to avoid unnecessary interventions and delayed treatment. Ca125 is a non-specific marker of peritoneal inflammation but it might be helpful in monitoring the treatment response.