Papillary Lesions of the Male Breast: A Study of 117 Cases and Brief Review of the Literature Demonstrate a Broad Clinicopathologic Spectrum.

Papillary lesions of the male breast (PLMB) are uncommon. To date, PLMB have been reported as individual case reports and in relatively small series. We reviewed cases of PLMB diagnosed at our medical center over a 19-year (2000-2019) period. A total of 117 cases were identified, with an age range of 7 months to 88 years. These cases included 3 of papillary ductal hyperplasia, 5 intraductal papillomas, 1 adenomyoepithelioma, 5 atypical papillomas (ie, papillomas with atypia), 51 papillary ductal carcinoma in situ, 14 encapsulated papillary carcinomas, 38 solid papillary carcinomas, and 8 invasive papillary carcinomas. Malignant papillary neoplasms, including invasive and noninvasive ones, had a mean size of 1.3 cm (range: 0.3 to 4.4 cm), and all were ER and HER2. Fifty-four percent (19/35) of carcinomas were treated with excision alone, 46% (16/35) underwent mastectomy, and 63% (22/35) had axillary lymph node sampling. Only one case had metastatic involvement of axillary lymph nodes. Of the cases with follow-up, no (0/8) invasive carcinoma showed distant metastasis or proved fatal, and no (0/23) noninvasive papillary carcinoma recurred. Two notable cases of PLMB were encountered: one of a 7-month-old boy with NF1 mutation and florid papillary hyperplasia, and another of a 57-year-old man with Klippel-Feil syndrome and bilateral solid papillary carcinoma, invasive and oligometastatic on one side and noninvasive on the other. On the basis of this study of PLMB cases, the largest to date, and review of literature, we conclude that PLMB span a broad clinicopathologic spectrum, and that both invasive and noninvasive papillary carcinomas have relatively good prognosis.