Intraductal papilloma with "comedo-like" necrosis, a diagnostic pitfall

Necrosis in the breast is more frequently associated with malignancies than benign conditions. In the latter, it may be diffuse as seen in infarcts, postpartum changes, and after anticoagulant therapy, or focal as in florid adenosis and juvenile papillomatosis. The goal of this study was to find other benign entities associated with necrosis. Using our pathology database from January 1994 to March 2003, we identified 10 cases of florid duct hyperplasia associated with luminal necrosis. Clinical information was collected and all slides were reviewed. The age of the patients ranged from 36 to 94 years (mean, 53.2 years). All patients underwent an initial excisional biopsy except for one who had a core biopsy. Patients presented with a palpable mass (6 cases) a radiographic density (3 cases), or nipple discharge (1 case). Findings correlated with the presence of an intraductal papilloma with adjacent or associated florid duct hyperplasia. Within the central luminal spaces of the florid duct hyperplasia, cellular debris associated with necrosis was present and was morphologically identical to that seen in comedo intraductal carcinoma. In fact, in two of the four consultation cases, these lesions were initially diagnosed as comedo carcinoma. Re-excision performed in three cases showed no atypia or malignancy. It is important to recognize the presence of comedo-like necrosis in florid duct hyperplasia associated with or adjacent to intraductal papillomas of the breast and not to misinterpret these findings as intraductal carcinoma. The necrosis may be secondary to reactive changes within the intraductal papilloma.