REPORT OF A CASE OF BENIGN CYSTIC MESOTHELIOMA

A 32-yr-old man was admitted to Anjo Kosei Hospital for the examinatio n of a cystic peritoneal lesion. This patient had a past medical histo ry significant for an appendectomy. Ultrasonography and computed tomog raphy revealed multiple cysts in the abdominal and pelvic cavities. An exploratory laparotomy was performed on July 1, 1993, revealing numer ous thin-walled and translucent cysts in the serosal tissues of the pa rietal and visceral abdominal peritoneum. These cysts were excised sur gically because of clinical suspicion of pseudo-myxoma peritonei, Micr oscopic examination revealed cysts within the thin cyst wall that were composed of fibrous connective tissue and lined by a single layer of cuboidal or flattened epithelium. Immunohistochemical and ultrastructu ral studies demonstrated that the lining cells were of mesothelial ori gin, and the diagnosis was benign cystic mesothelioma. In this paper, we present appropriate diagnostic and treatment procedures for benign cystic mesothelioma and discuss the particular usefulness of using imm unohistochemical methods to achieve a histological diagnosis.