Multiple papillomas: Risk of atypical lesions, carcinomas in situ and invasive carcinomas

Papillomas of the breast are benign tumors associated with underestimation of high-risk lesions. The heterogeneity of the definitions used and the low level of evidence in current studies prevent recommending guidelines for clinical management of multiple papillomas (MP). The primary objective is to estimate the risk of atypical lesions (AL), carcinomas in situ (CIS) and/or invasive carcinomas (IC) associated with MP. Secondary objectives aim to evaluate the risk factors for AL, CIS and/or IC, and to assess the risk of recurrence of MP.

This is an observational descriptive multicenter study. Patients with at least 2 synchronous papillomas on surgical specimen(s) between 2010 and 2022 were included. AL, CIS, and IC diagnosed before surgery were excluded.

One hundred twenty-eight patients were diagnosed with MP, mainly discovered on single lumpectomy specimens (57 %) and unilateral (80.5 %). Multiple nature of papillomas was a postoperative diagnosis in 47.7 % of cases. Twenty-six patients (20.3 %) had at least one AL. Three patients (2.3 %) were diagnosed with IC. The multivariate logistic model demonstrates that microcalcifications have a significant association with AL, CIS, and/or IC (OR 3.78; 95 %CI [1.24 - 11.47]; p = 0.02). During a median follow-up time of 23 months, 26 patients (21.7 %) underwent surgery or macrobiopsy for recurrence, including 6 (5.0 %) for CIS or IC.

Because of the risk of underestimation at preoperative histology and their frequent association with AL, CIS and/or IC, MP require surgical excision. Due to frequent recurrences, clinical and radiological post-treatment follow-up should be recommended annually.