Thank you for your question. Tuberous breast is a congenital abnormality that occurs during puberty breast development in BOTH men and women due to strong attachment between the chest wall and overlying skin, a constriction ring. It can be classified by a combination of reduced breast diameter, underdevelopment of the breasts, areolar overgrowth, protrusion of the nipple areola complex, breast sagging, and breast asymmetry. Interestingly, it can often happen on only one side of the body. The causes of tuberous breasts are still undefined and unclear. Majority of the cases seem to be isolated cases, where the mother and father have no prior problems. However, a recent study by Klinger et al. titled “Tuberous Breast: Morphological study and overview of a borderline entity” observed 2 cases of tuberous breasts in twin males with gynecomastia suggesting a role of genetic influence and familial transmission. However, more studies are needed to look into this and right now it seems that the majority of cases occur sporadically during puberty development. Hope this helps.