Nodular fasciitis of the male breast: a case report.

A case of nodular fasciitis is reported that involved the breast parenchyma of a 40-year-old man. The differential diagnosis of nodular fasciitis in the male breast mainly includes fibromatosis and myofibroblastoma. However, other benign and malignant spindle cell lesions of the breast, such as pseudoangiomatous stromal hyperplasia and especially spindle cell metaplastic carcinoma and fibrosarcoma, may enter the differential. The classic histomorphologic features and immunohistochemical findings are helpful in arriving at the correct diagnosis. The patient underwent a total excision of the lesion and is free of disease after 14 months. To our knowledge, this is the first reported case of a lesion of this type in the male breast.