A case of leiomyoma of the breast.

Leiomyomas are common in the genitourinary and gastrointestinal tracts and less frequent in skin and soft tissue. It is quite uncommon for them to develop in the breast, especially in the breast parenchyma. Only 12 cases of leiomyoma in the breast parenchyma proper apart from the areola have been reported. We present a thirteenth case, the first to be reported in Japan. Its clinical features, mammographic and ultrasonographic findings, histological and immunohistochemical characteristics are quite consistent with previous reports.