Malignant Desmoplastic Type Mesothelioma Mimicking a Fibrous Pseudotumor of the Tunica Vaginalis: A Case Report and Literature Review

摘要

Malignant mesothelioma is an uncommon tumor of serosal surfaces. The most common sites of origin includethe pleura and the peritoneum. Malignant mesothelioma of the tunica vaginalis testis is rare. We describe a 78 year-oldman with a 2-month history of a rapidly enlarging scrotum. The initial pathologic diagnosis was fibrous pseudotumor bythe presence of cellular spindle cells and the background of dense fibrous tissue. However, further immunohistochemistryrevealed characteristic features of desmoplastic variant mesothelioma. Mesothelioma of the peritoneum and tunica vaginalistends to be the epithelioid type. The purely desmoplastic-type mesothelioma of the tunica vaginalis has never beenreported. Immunohistochemistry is essential to the diagnosis.