Fibromatosis of the male breast with concurrent florid-type gynecomastia: Report of a case and review of literature.

Fibromatosis is a soft tissue lesion with infiltrative capacity, and is formed of proliferation of fibroblastic and myofibroblastic cells with a significant risk for local recurrence, but no metastatic potential. Fibromatosis is uncommon in the mammary gland, and accounts for less than 0.2% of all primary breast lesions. To the best of our knowledge, it has not been described in the setting of male breast with concurrent florid-type gynecomastia. We report a rare case of a 45-year-old male presenting with a palpable breast mass that was suspicious of carcinoma clinically. Failure of exclusion of metaplastic carcinoma and other lesions in repeated core biopsies lead to excision, which documented the intra-mammary origin of the lesion and established the diagnosis of fibromatosis. The current case demonstrates that fibromatosis in the male breast may have features and a presentation that can be confused with breast cancer. When obvious breast changes and history do not correlate with routine diagnostic measures, the presence of an unusual breast or chest wall tumor, such as a fibromatosis, should be considered in the differential diagnosis.