A Retrospective Population-Based Analysis of 19,640 Pediatric and Young Adult Males with Gynecomastia

Gynecomastia is the most common breast condition in pediatric and young adult males, yet large-scale studies evaluating its etiologies, risk factors, and management remain scarce.In adolescents, gynecomastia is most frequently idiopathic or obesity-related, while secondary causes are rarer.Persistent presentations may cause psychosocial distress and lead to surgical correction, though the optimal diagnostic approach remains controversial.We conducted a retrospective, population-based study of 19,640 males aged 10-25 years with documented gynecomastia diagnosis, extracting demographic and clinical variables including age, body mass index (BMI) Z-scores, family history, comorbidities, medication exposure, and surgical status.Reporting was in accordance with the STROBE guidelines.Most patients were idiopathic (74.3%), followed by medication-related (23.1%) and pathology-associated (3.4%).For patients with pathology-associated cases compared with other etiologies, the mean age and mean BMI Z-score were higher, and surgeries were more frequent (all p<0.001).The prevalence of pathology increased with age, whereas obesity-related and familial cases predominated in younger children.Morbid obesity was significantly associated with higher surgical rates (5.2% vs. 2.1% in non-obese, p<0.001).Independent associations with surgical intervention included older age (odds ratio (OR 1.20), higher BMI Z-score (OR 1.30), 2 affected siblings (OR 8.35), and testicular tumors (OR 14.06).Model discrimination (area under the curve=0.973)was excellent.In conclusion, gynecomastia in younger boys is primarily idiopathic or obesity-related, while older adolescents are more often diagnosed with secondary causes.Age-and risk-tailored diagnostic strategies, including early screening for obesity, family history, and medication exposure may optimize management and guide surgical decision-making.