Evaluation of Imaging-Guided Peritoneal Biopsy in Diagnosis of Ascites of Unknown Origin

Ascites is a common clinical problem, which can be a result of liver cirrhosis, neoplasm, tuberculous or pyogenic peritonitis, heart failure, nephrosis, and pancreatic disorders. This study aimed to evaluate the role of imaging-guided peritoneal biopsy in the diagnosis of ascites of unknown origin (ascites of local cause). Sixty-three patients with ascites of unknown etiology were included. Abdominal ultrasonography (US) with colored Duplex was performed, followed by laboratory investigations such as, ascitic fluid samples, magnetic resonance imaging, multislice computed tomography (CT), or PET/CT scan (if indicated). Imaging-guided peritoneal biopsy such as US-guided or CT-guided percutaneous peritoneal biopsy (in cases of failure of US-guided technique) of omentum or extravisceral masses was performed. Cytological and histopathological examinations of the tissue specimens were done by a single experienced pathologist. Other more invasive procedures (e.g., laparoscopy) were needed when the imaging-guided biopsy was not diagnostic. Fifty-four patients underwent US-guided biopsies, 48 patients were successfully diagnosed, and other 9 patients underwent CT-guided biopsies (not accessible by US-guided modality); laparoscopy was needed only in 6 patients. Malignant peritoneal pathology was found in 48 patients, while tuberculous peritonitis was diagnosed in 14 patients. Imaging-guided biopsies had perfect sensitivity (100%) and negative predictive value (100%) in differentiating neoplastic lesions. Percutaneous imaging-guided biopsy (US/CT guided) of the peritoneum, omenta, and mesentery has been established as a safe, simple, noninvasive, and well-tolerated procedure with high diagnostic accuracy. It can minimize further unnecessary invasive procedures such as laparoscopy.