Breast hypoplasia in the adolescent girl can either be unilateral or bilateral. Unilateral hypoplasia is present when there is significant discrepancy in mammary size between breasts and there is no evidence of macromastia of the contralateral breast. 1 bilateral breast hypoplasia may be either symmetric or asymmetric. 2 histologically, both unilateral and bilateral hypoplastic breast tissue. Breast hypoplasia is also commonly called breast hypomastia or micromastia. The term describes a condition in which one or both breasts never mature or develop properly. Hypomastia can be the result of several possible known causes or might be idiopathic. Mammary hypoplasia, also known as insufficient glandular tissue or igt, is a very uncommon condition that can cause low or no milk production. Women with mammary hypoplasia simply did not develop proper mammary tissue during adolescence, but their breasts may be small or large. Insufficient glandular tissue (breast hypoplasia) most women produce more than enough milk for their baby (or babies). A small percentage of women have breasts that do not produce enough milk because of insufficient glandular tissue (igt). It is breast shape, placement, and asymmetry that indicate hypoplasia not necessarily size. Normal-sized breasts that are lacking glandular tissue may be made up of fatty tissue that will sufficiently fill a bra cup. Breast hypoplasia is a condition which is characterized by underdevelopment of the breast. Pathology congenital hypoplasia associations include ulnar-mammary syndrome poland syndrome turner. hypoplasia and breastfeeding insufficient glandular breast tissue. Primary lactation failure may occur as a result of various factors such as previous breast surgery, hormonal issues and breast hypoplasia (also referred to as insufficient glandular tissue or igt). While most womens breasts become filled with milk within three days of delivery, hypoplastic breasts stay soft because there isnt enough glandular tissue to produce much milk.