Papilloma on core biopsy: excision vs. observation.

Background: Intraductal papillomas (IPs) are commonly seen breast lesions with variable clinical presentation. For a palpable lesion and/or evidence of cellular atypia and/or pathologic nipple discharge, excision is warranted to rule out adjacent carcinoma, while for asymptomatic IPs lacking atypia current data for excision vs. observation are controversial. We reviewed outcomes of IPs diagnosed at our institution.
Methods: With IRB approval, we reviewed consecutive patients with IPs seen on core biopsy (CBx) between 2005 and 2013. All patients had an excision, with subspecialty breast pathology review of CBx and excisions. The rate of upgrade to cancer on excision was recorded. Differences between atypia and no-atypia groups were determined by two-tailed t test and Fisher's exact test.
Results: We identified 97 patients (age range 31-83 years) with IPs on CBx. Among 52 atypical IPs, DCIS was seen in 11 (upgrade 21 %). In 45 IPs without atypia, 3 cancers were seen (upgrade 6. %): 2 had palpable lesions and were found to have DCIS, and 1 invasive cancer was found in a non-palpable mammographically detected BIRADS 4C lesion, whose Cbx result was discordant. If the 2 palpable lesions are excluded, the upgrade rate for IPs without atypia is 2.2 %.
Conclusions: This series shows a low upgrade rate for IP without atypia seen on CBx in the absence of a palpable mass and radiographic/pathologic discordance, suggesting that a surgical biopsy may not be necessary. Further prospective studies to better estimate the upgrade rate for IPs without atypia may be helpful.