Pleomorphic hyalinizing angiectatic tumor of the male breast: a heretofore unreported occurrence.

Pleomorphic hyalinizing angiectatic tumor (PHAT) is considered an unusual mesenchymal tumor of intermediate malignant potential that is distinguished by a prominent angiectatic vasculature with clusters of thin-walled, fibrin-lined vessels surrounded by sheets of spindled and pleomorphic cells. This lesion occurs mostly in the subcutaneous soft tissues of the lower extremities. In this paper, the authors report the first case of PHAT involving the breast parenchyma of a 75-year-old man. The patient was referred to the hospital with a history of a painless left breast mass that had been growing for several years. The lesion did not recur after surgery. The tumor exhibited histopathologic and immunohistochemical features identical to those of a PHAT of other sites. The purpose of this report is to add a rare tumor to the differential diagnosis of mammary spindle cell neoplasms.