Non-mass-associated intraductal papillomas: is excision necessary?

Intraductal papillomas (IDPs) of the breast can be associated with a variety of clinical symptoms and radiologic findings. Surgical excision is often recommended based on the possibility of an associated high-grade lesion. Although the rate of upgrades has been extensively evaluated for IDPs, many studies are hindered by broad inclusion criteria, a lack of pathologic-radiologic concordance, and no standard definition of what constitutes an upgrade. In the current study, we evaluate the risk of upgrade for a specific subset of IDPs: non-mass-associated IDPs. We identified all breast needle core biopsies with a diagnosis of IDP between 2003 and 2010. Patients with associated masses, architectural distortion, or ipsilateral breast cancer were excluded. All needle core biopsy slides and relevant imaging studies were reviewed to ensure pathologic-radiologic concordance. Excision pathology was also reviewed; an upgrade was defined as the presence of ductal carcinoma in situ or invasive carcinoma in the excision. Seventy-nine IDPs that met inclusion criteria were identified and were further divided into 3 histologic categories: micropapilloma, fragmented IDP, and atypical IDP. Micropapillomas and fragmented IDPs had no upgrades (0/37). In patients who did not undergo excision, none subsequently developed ipsilateral breast cancer (follow-up, 50-61 months). This is in contrast to atypical IDPs that had a 33% upgrade rate. One patient with an unexcised atypical IDP developed ipsilateral breast cancer within 2 years. Our data suggest that conservative follow-up is reasonable for non-mass-associated IDPs without atypia regardless of microscopic size, provided that careful pathologic-radiologic correlation is achieved.