Periductal mastitis. Masquerading as carcinoma.

Periductal mastitis (mammary duct ectasia) is a little appreciated, often unrecognized entity that may present to the dermatologist. We present our experience with this disease and hope to familiarize the reader with a condition not well known to most dermatologists. Periductal mastitis is a benign mammary duct disease that begins with periductal inflammation and progresses to ductal dilatation with minimal inflammation (ductal ectasia). The clinical and radiographic appearance of this disease can be indistinguishable from carcinoma of the breast.