Atypical evolution of a calcified lipid cyst presenting spontaneously as a suspicious cluster of microcalcifications.

We report an infrequent mammographic case in which a gross-calcified lipid cyst evolved spontaneously to form a cluster of pleomorphic microcalcifications which were indistinguishable from those seen in breast cancer. The biopsy performed was consistent with fat necrosis. Ultrasonography of the specimen showed a nodule with mixed echogenicity surrounded by a hypoechoic rim. To our knowledge, this behavior is extremely rare, with only one similar case reported in the literature.