A male breast reduction, or Gynaecomastia, is a type of cosmetic surgery to help men whose breast tissue is abnormally large in size and appearance. Gynecomastia is a medical term that means “women-like breasts”, and lay people sometimes refer to it as “Manboobs”. Male breast Reduction Gynecomastia is far more common than many realize. Gynecomastia affects an estimated 30 to 60 percent of the male population. It may affect only one breast or both.