A Clinical Algorithm for Gynecomastia: From Diagnosis to Surgical Management.

backgroundGynecomastia is a heterogeneous disorder spanning the full pediatric-to-adult age range; however, comprehensive single-institution analyses that integrate endocrine, comorbid, drug-related, and surgical perspectives within one framework remain limited. We characterized the demographic and etiologic landscape of gynecomastia in a large retrospective cohort, propose a practical diagnostic algorithm derived from these patterns, and summarize the institutional experience with surgical management.

methodsWe retrospectively reviewed all male patients with an electronic-medical-record diagnosis of gynecomastia at two tertiary academic hospitals between January 2011 and March 2026. True gynecomastia was confirmed clinically and, where indicated, by ultrasonography, mammography, or magnetic resonance imaging. Patients were categorized by primary etiology (physiologic, drug- or substance-induced, endocrine, pathologic systemic, or idiopathic) using a standardized diagnostic workflow, and surgical candidates were graded according to the Simon classification.

resultsOf 754 patients screened, 562 met criteria for true gynecomastia (pediatric ≤ 17 years, 30 [5.3%]; adult ≥18 years, 532 [94.7%]; mean age 58.7 ± 19.8 years; median 64, range 0-95). Bilateral disease accounted for 75.9% of patients with documented laterality. Idiopathic disease was the largest category (362; 64.4%), followed by drug- or substance-induced disease (135; 24.0%), pathologic systemic disease (43; 7.7%; predominantly chronic liver and kidney disease), endocrine disorders (13; 2.3%), and overt physiologic gynecomastia (6; 1.1%). Spironolactone (71 patients; 52.6% of drug-induced cases) and antiandrogen / androgen-deprivation therapy agents (28; 20.7%) jointly accounted for nearly three quarters of drug-induced disease. Etiologic distribution differed markedly by age: physiologic and idiopathic causes predominated in adolescents, whereas drug-induced disease rose sharply from the fifth decade onward and accounted for ≈26-29% of cases in patients aged 50-80 years. Forty-three patients (7.7%) underwent surgical correction (mean age 33.7 ± 18.9 years), most commonly for long-standing persistent disease or cosmetic and psychosocial indications; surgical conversion was substantially higher in idiopathic (9.3%) than in drug-induced (2.2%) or systemic pathologic disease (2.3%). Histopathology confirmed benign glandular hyperplasia in all 43 surgical specimens; no occult male breast carcinoma or other malignant tissue was identified (0 of 43), and patients with male breast carcinoma at initial presentation were excluded a priori.

conclusionsAcross a 15-year cohort, idiopathic and drug-induced disease (chiefly spironolactone and antiandrogen-class agents) accounted for nearly 90% of adult cases. A stepwise algorithm based on examination, medication review, and selective endocrine and radiologic testing classified etiology in routine practice, and surgery matched to Simon grade remained the definitive treatment for long-standing, severe, or psychosocially distressing disease. LEVEL OF EVIDENCE III: 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 .