ABSTRACT
Purpose@#Gynecomastia is a common condition caused by various factors and characterized by the overdevelopment of the male breast glandular tissue. It can cause pain and discomfort, which may require treatment. This study aimed to evaluate the efficacy of tamoxifen in the treatment of idiopathic gynecomastia. @*Methods@#We retrospectively analyzed the medical records of 101 patients who underwent medical treatment for idiopathic gynecomastia using tamoxifen from January 2005 to December 2018. We examined the clinical characteristics that affected resolution and recurrence. @*Results@#The overall resolution rate of gynecomastia among the patients treated with tamoxifen was 89.1%, and the overall recurrence rate was 15.6%. Large size at diagnosis and longer duration of symptoms were significantly different between patients who experienced resolution and those who did not (p=0.017 and p=0.019, respectively). The dosage of tamoxifen did not affect the resolution rate (p=0.609). None of the clinical characteristics were significantly different between patients who experienced recurrence and those who did not. @*Conclusion@#Our study showed that tamoxifen may be an effective treatment for idiopathic gynecomastia.