Benign multicystic peritoneal mesothelioma: cases reports in the family with diverticulosis and literature review.

We report on benign multicystic peritoneal mesothelioma in two siblings whose family had a history of multiple familial diseases including diverticulosis. After a genetic evaluation and a chromosomal analysis, we were not able to identify a specific genetic cause of the family's pattern of disease. We assumed that previous surgical procedures and the chronic inflammatory process from diverticulitis were the underlying etiology. Both patients had multiple recurrences with indolent courses similar to those reported in other cases. After the recurrences, one patient was treated with cystic aspiration and the other with hormones. The cysts in both cases regressed partially but the patients were relieved of their clinical symptoms, for 2 years after cystic drainage in one case and for 5 years after hormonal treatment in the other.