Peritoneal Mesothelioma: A Rare Cause of Abdominal Ascites

Abstract

Mesothelioma is a fatal malignancy typically located in the pleura of men in their 50's, many years after asbestos exposure. Peritoneal mesothelioma is rare and may be difficult to diagnose by cytologic analysis of ascetic fluid as it is often negative or inconclusive. Patients commonly present with nonspecific symptoms, however, the Gastroenterologist may be called to consider this in the work-up of ascites. A 23 year old female presented with increased abdominal girth, weight gain, and abdominal cramping. Pelvic ultrasound revealed moderate to large amount of simple-appearing nonspecific free fluid in the cul-de-sac and bilateral adnexal regions. Various examinations over the next few months revealed increased free fluid progressing to perihepatic ascites. Transvaginal paracentesis was performed with fluid sent for cytology revealing reactive mesothelial cells. The patient underwent exploratory laparoscopy and ascites analysis showed low serum ascites albumin gradient (SAAG) with high total protein. During the laparoscopy, several nodules attached to the peritoneum in the upper abdomen were biopsied. Histologic and immunohistochemical analysis of the biopsies demonstrated malignant mesothelioma, epithelioid type. The patient was subsequently referred to a tertiary cancer center for treatment with cytoreductive surgery and hyperthermic intraperitoneal chemotherapy.Figure 1Figure 2Figure 3This is a case of peritoneal mesothelioma, a rare fatal tumor, presenting with malignancy-related ascites in a young woman. Occupational and environmental exposure to asbestos remains the leading cause of mesothelioma with exposure preceding diagnosis by 15-60 years. 85% of cases of mesothelioma occur in men in their mid-50's who have identifiable asbestos exposure. This patient presents a rare case: a young female with peritoneal mesothelioma with no identifiable asbestos exposure. There are only 200-400 cases of peritoneal mesothelioma diagnosed in the United States each year which account for 10-15% of cases of mesothelioma overall. Symptoms are often non-specific and routine laboratory tests are not helpful in making this diagnosis. Although cytology of ascites fluid is usually helpful with peritoneal carcinomatosis, it is often inconclusive in instances of peritoneal mesothelioma, as demonstrated in this patient. Review of the literature indicates that this diagnosis was expected to peak in 2015 making increased awareness of this disease and its diagnostic challenges vital.