Background: Benign multicystic peritoneal mesothelioma (BMPM) is an uncommon condition.
Case report: We observed a typical case of BMPM occurring in a 57-year-old man who presented with a painful mass of the lower right quadrant. The pathology using immunostaining gave the diagnosis.
Discussion: The diagnosis of BMPM can be suspected on the basis of imaging findings, but is usually confirmed by pathology. The only treatment for BMPM is surgical resection. Prognosis is good despite frequent recurrences. Two main hypotheses based on etiopathology can be discussed: does BMPM consist of a mesothelioma proliferative and reactional lesion or is it a real mesothelioma tumor?