Clinical Characteristics of Asymmetric Bilateral Gynecomastia: Suggestion of Desirable Surgical Method Based on a Single-Institution Experience

BACKGROUND: Asymmetric bilateral gynecomastia (ABGM) is uncommon, and reports on its characteristics are rare. In the present study, we investigated the clinical characteristics and surgical treatment of ABGM. METHODS: We conducted a retrospective study of 1159 patients with gynecomastia who underwent subcutaneous mastectomy with liposuction at Damsoyu Hospital from January 2014 to February 2016. We then analyzed differences in the characteristics and operative results between two groups of patients: those with asymmetric and symmetric gynecomastia. Asymmetric gynecomastia was defined as gynecomastia meeting both of the following criteria: (1) upon physical examination, the size of the palpable mass below the nipple-areolar complex was twice as large as the smaller one, and (2) upon ultrasonography, the depth of the glandular tissue under the nipple-areolar complex was twice as large as the smaller one. RESULTS: Fifty-four patients were diagnosed with asymmetric gynecomastia. Among them, 51 had ABGM and three had unilateral gynecomastia. In the asymmetric group, more patients had a larger left than right breast (33 patients, 64.7%). The incidence of true-type (entirely glandular) breasts was significantly higher in the asymmetric group (84.3%) than in the symmetric group (p < 0.001). The asymmetry ratios in the asymmetric and symmetric groups were 1.87 ± 2.07 and 0.20 ± 0.16, respectively (p < 0.001). CONCLUSION: Bilateral mastectomy provided an acceptable and symmetric cosmetic outcome in patients with ABGM. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .