Abstract
Angioleiomyoma is a type of pericyte tumor with a benign biological behavior. It typically features proliferation of mature perivascular smooth muscle cells around blood vessels. Angioleiomyoma may be categorized into solid, cavernous or venous subtypes. Usually, it occurs in the dermis or subcutaneous tissue, while the rare cavernous subtype is most common in the upper extremities. Only a small number of cases of angioleiomyoma located in the mediastinum have been reported to date. In addition, there are few reports of mediastinal angioleiomyoma described as a cavernous histopathological subtype. The present study reported a case of mediastinal angioleiomyoma presenting as an unusual cavernous histopathological subtype. The histopathological and immunohistochemical features, based on which a diagnosis of cavernous angioleiomyoma was confirmed, were desmin- and smooth muscle actin-positive expression in spindle tumor cells, as well as ETS-related gene (ERG)- and CD31-positive expression in vascular endothelial cells. Cavernous angioleiomyoma of the mediastinum rarely occurs in the clinical setting but should be considered as a differential diagnosis of mediastinal tumors.