Ossifying fibromyxoid tumor of the breast mimicking fibroadenoma: a case report and differential diagnoses.

Abstract

An 80-year-old woman presented with a palpable mass in the right breast. Mammographic findings were consistent with calcified fibroadenoma. An ultrasound was performed that showed a solid nodule with peripheral calcification. A core biopsy was obtained that revealed a spindle cell proliferation with a shell of mature bone. The histologic features, in combination with immunohistochemical studies, were those of an ossifying fibromyxoid tumor. Complete excision of the specimen further confirmed the diagnosis. To the best of our knowledge, this is the first reported case of ossifying fibromyxoid tumor occurring in the breast. We review the current literature on ossifying fibromyxoid tumor and discuss the differential diagnoses when confronted with bland spindle cells on a core biopsy of the breast.