[Benign multicystic peritoneal mesothelioma]

Benign multicystic peritoneal mesothelioma is a rare benign tumor originating from the peritoneum, affecting mostly young, fertile women. Its presentation is non-specific, thus the final diagnosis is made after the histological examination. A young female patient presented with incarcerated inguinal hernia of which an emergency surgery was performed. During the operation a cystic mass neighboring the round ligament in the canal of Nuck was removed. No inguinal hernia was found. The histological examination confirmed the diagnosis of benign multicystic mesothelioma. The patient was referred to a center performing hyperthermic intraperitoneal chemotherapy, where laparoscopic exploration was performed. The second surgery revealed no residual tumor or any other pathology. A 41-year-old male patient, 4 years before presenting at our ward, had an elective umbilical hernia repair surgery. During the operation 2 cm big cystic mass was removed from the peritoneum, and the histological examination revealed benign multicystic mesothelioma. In 2018, acute surgery was performed due to a periappendicular abscess, while during the surgery a multicystic mass situated on the distal end of the appendix was also removed. The pathological finding confirmed the recurrence of the first tumor. The radiological examination did not find any signs of residual tumor mass anywhere else. The chances of malignant transformation in cases of benign multicystic peritoneal mesothelioma are low. The suggested treatment is en bloc surgical removal of the mass, however, in these cases recurrence is still 50%. If during follow-ups the recurrence of the tumor is found, a total peritonectomy or hyperthermic intraperitoneal chemotherapy is advisable. Orv Hetil. 2019; 160(21): 839-843.