Rapid growth of pseudoangiomatous hyperplasia of mammary stroma in axillary gynecomastia in an immunosuppressed patient.

Pseudoangiomatous hyperplasia of mammary stroma is a rare, benign mesenchymal proliferation that sometimes mimics angiosarcoma. To our knowledge, it has not been reported in men. We report the first case of this unusual entity in a man. This case was most unusual in that it occurred in a clinical setting of immunosuppression, in axillary gynecomastia, and was growing rapidly.