Membranous fat necrosis of the breast: diagnosis by minimally invasive technique

Clinical and mammographic features of membranous fat necrosis (MFN) may simulate breast malignancy and tissue sampling is essential for accurate diagnosis. The aim of our study was to evaluate the clinical and imaging findings in these patients. Retrospective review of the records of breast biopsies (n = 1200) during the 5-year period 1998 to 2002 revealed eight (0.67%) cases of histologically proven MFN. Seven of the eight patients had a history of breast trauma or surgery. Seven patients underwent mammography: normal in two, a mass with curvilinear calcifications in one, and heterogeneous calcifications in four. Four patients underwent surgical excision of a palpable mass, one patient had complete excision of calcifications with large core biopsy technique, and three patients had stereotactic vacuum-assisted mammotome biopsy (VAMB). MFN should be included in the differential diagnosis of lesions in a breast with previous trauma or surgery. A minimally invasive diagnostic procedure should be considered in order to avoid excessive excisional surgery.