Bilateral extensive ductitis obliterans manifested by bloody nipple discharge in a patient with long-term diabetes mellitus.

Ductitis obliterans or mastitis obliterans is a rare late manifestation of mammary ductal ectasia. We describe a long-term diabetic patient who presented with bilateral bloody nipple discharge and poorly defined nodularities around the nipple of both breasts. The ductography showed multiple segments of irregular ductal narrowing and intraluminal filling defects in both breasts. The bilateral resection of the sub-areolar portion of the breast showed exuberant fibrous obliteration of the large- and medium-sized ducts by granulation tissue associated with few histiocytes. Ductal dilatation and intraductal accumulation of histiocytes was also present. This represents a late and florid form of mammary ductal ectasia. Differential diagnostic considerations including fibrocystic changes, diabetic sclerosing lymphocytic lobulitis, idiopathic granulomatous lobular mastitis, and periductal mastitis (Zuska disease) are discussed. Accurate diagnosis can help avoid or limit radical surgeries in this group of patients.