A rare cause of mastalgia: Dercum's disease (adiposis dolorosa).

Among the symptoms reported by patients undergoing breast imaging, pain is one of the most common. Mastalgia is generally classified as cyclic, noncyclic, or extramammary. A rare cause of breast pain is Dercum's disease, or adiposis dolorosa, a condition characterized by multiple, often painful subcutaneous lipomas. Painful breast lipomas have not been described in the literature so far. The diagnosis is made by clinical means supported by diagnostic imaging. We report the case of a 58-year-old postmenopausal woman affected by Dercum's disease in the breast. Ultrasound examination showed multiple oval, well-defined, hyperechoic lesions suggestive of breast lipomas. No significant features were detected by mammography.