Papillomas of the breast 15 mm or smaller: 4-year experience in a community-based dedicated breast imaging clinic.

PURPOSE: To determine the significance of small, often mammographically occult and asymptomatic papillomas of the breast 15 mm and smaller.
METHODS: Four-year retrospective review of papillomas of the breast in a community-based dedicated breast imaging center, with a selected cohort of 179 papillomas 15 mm or smaller in 147 patients, all completing image-guided core biopsy followed by surgical excision.
RESULTS: Of 179 papillomas 15 mm or smaller, 36 % were abnormal (24 % atypia; 12 % cancer). Twenty-one percent had a surgical upgrade diagnosis. One hundred forty-six benign papillomas by core biopsy yielded 7 (4.7 %) cancers and 25 (17 %) atypias (atypical ductal hyperplasia (ADH), atypical lobular hyperplasia (ALH), or lobular carcinoma-in situ) at surgical excision. Seven of 34 (14 %) of very small papillomas (5 mm or smaller) showed cancer. Twelve of 72 (11 %) and 8 of 36 (13 %) papillomas showed cancer in normal-risk and high-risk patients, respectively. Increasing age (70+ years) associated strongly with increasing risk of papillomas with cancer (10 of 35, 29 %). Thirteen unsuspected papillomas in 10 patients with new nonpapillary breast cancers yielded 3 atypias and 3 additional cancers, changing surgical management in half of these patients. Breast ultrasound identified 44 % of papillomas as incidental findings, all mammographically occult and asymptomatic.
CONCLUSIONS: There is no size threshold below which a papilloma of the breast can be safely watched or ignored without risking a missed diagnosis of atypia or cancer. Identification of papillomas in patients with new nonpapillary breast cancers can change patient management in up to half of these patients. Finally, breast ultrasound significantly enhances identification of unsuspected papillomas.