Imaging modalities used in mammary fibromatosis

Mammary fibromatosis is a rare neoplastic proliferation of fibroblastic cells. Usually seen in abdominal and extra-abdominal sites, it is rarely seen in the breast. Patients with mammary fibromatosis usually present with a firm palpable mass with or without dimpling and skin retraction–often mimicking breast carcinoma. Here, we present a case of mammary fibromatosis in a 49-year-old woman who presented with a palpable lump in her right breast. Mammography tomosynthesis revealed architectural distortion which was seen on ultrasonography as a hypoechoic area. The patient underwent a wire-guided excision where the histology of this specimen showed irregular spindle cell proliferation with hemosiderin deposition, confirming mammary fibromatosis. Further re-excision of margins revealed no evidence of residual fibromatosis, and the patient underwent subsequent surveillance mammograms to ensure there was no recurrence.