Incidental Pathologic Findings in Young Men with Gynecomastia.

[BACKGROUND] Pathologic examination of young adult gynecomastia tissue is controversial given the low incidence of breast carcinoma in this population. The authors examined the pathologic findings in a large cohort of adolescents with gynecomastia to evaluate the need for routine tissue analysis in this population.

[METHODS] A retrospective review of men who underwent unilateral or bilateral mastectomy for gynecomastia at a single institution between February of 2007 and November of 2019 identified demographics, medical history, surgical characteristics, and pathologic findings. Descriptive statistics were performed.

[RESULTS] A total of 268 male patients were included. Mean age was 16.6 years. Mean body mass index was 27.8 kg/m2, and 42.5 percent of the sample was obese. The majority (83.2 percent) underwent bilateral subcutaneous mastectomy. There were no abnormal histopathologic findings in 95.1 percent. Among the 13 patients with abnormalities, eight (3 percent) had nonproliferative changes, two (0.8 percent) had proliferative changes without atypia, two (0.8 percent) had atypical ductal hyperplasia, and one (0.4 percent) had both bilateral atypical ductal hyperplasia and unilateral ductal carcinoma in situ. No patients had invasive carcinoma. The three patients with atypical ductal hyperplasia and/or ductal carcinoma in situ were obese but had no other breast cancer or gynecomastia risk factors.

[CONCLUSIONS] Findings conferring potentially increased risk of developing breast cancer were identified in three male adolescents (1.2 percent). Incidence of these findings is similar between male adolescents and similarly aged female adolescents undergoing breast reduction surgery. Although worrisome pathology results are rare, too little is known about the natural history of atypical proliferation and ductal carcinoma in situ in young men to recommend against routine analysis.

[CLINICAL QUESTION/LEVEL OF EVIDENCE] Risk, IV.