Mammary Myofibroblastoma: Report of a Case and Review of the Literature.

Mammary myofibroblastoma is a benign mesenchymal tumor composed of fibroblasts, myofibroblasts, and a variable number of adipocytes. Mammary myofibroblastoma usually occurs in men of older age and is less common in postmenopausal women. It may also happen in extramammary sites along the milk line. In this instance, it is referred to as mammary-type myofibroblastoma. Rarely multifocal and bilateral tumors have been described. Clinically and radiologically, it can be misinterpreted as a malignant tumor due to its rarity. Size usually does not exceed 3 cm. The diagnosis requires clinicopathological correlation with morphological and immunohistochemical evaluation, especially in limited biopsy specimens. We herewith describe a rare case of mammary myofibroblastoma in a 37-year-old female patient. We also review the literature focusing on the potential differential diagnostic issues and discuss this tumor's ultrastructural and cytogenetic findings.