Gynecomastia | EPFL Graph Search

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Gynecomastia (also spelled gynaecomastia) is the abnormal non-cancerous enlargement of one or both breasts in males due to the growth of breast tissue as a result of a hormone imbalance between estrogens and androgens. Gynecomastia can cause significant psychological distress or unease. Gynecomastia can be normal in newborn male babies due to exposure to estrogen from the mother, in adolescent boys going through puberty, in older men over age 50, and/or in obese men. Most occurrences of gynecomastia do not require diagnostic tests. Gynecomastia may be caused by abnormal hormone changes, any condition that leads to an increase in the ratio of estrogens/androgens such as liver disease, kidney failure, thyroid disease and some non-breast tumors. Alcohol and some drugs can also cause breast enlargement. Other causes may include Klinefelter syndrome, metabolic dysfunction, or a natural decline in testosterone production. This may occur even if the levels of estrogens and androgens are both appropriate, but the ratio is altered. Gynecomastia is the most common benign disorder of the male breast tissue and affects 35% of men, being most prevalent between the ages of 50 and 69. It is normal for up to 70% of adolescent boys to develop gynecomastia to some degree. Of these, 75% resolve within two years of onset without treatment. If the condition does not resolve within 2 years, or if it causes embarrassment, pain or tenderness, treatment is warranted. Medical treatment of gynecomastia that has persisted beyond two years is often ineffective. Gynecomastia is different from "pseudogynecomastia", which is commonly present in men with obesity. Medications such as aromatase inhibitors have been found to be effective and even in rare cases of gynecomastia from disorders such as aromatase excess syndrome or Peutz–Jeghers syndrome, but surgical removal of the excess tissue can be needed to correct the condition. In 2019, 24,123 male patients underwent the procedure in the United States, accounting for a 19% increase since 2000.

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Role of the androgen receptor in the human breast epithelium

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Breast cancer is the most common malignancy in women worldwide and understanding the risk factors affecting it is key for prevention. The relative risk of developing breast cancer is related to exposure to both endogenous hormones and exogenous natural and ...

EPFL2022

Sex differentiation in grayling (Salmonidae) goes through an all-male stage and is delayed in genetic males who instead grow faster

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Fish populations can be threatened by distorted sex ratios that arise during sex differentiation. Here we describe sex differentiation in a wild grayling (Thymallus thymallus) population that suffers from distorted sex ratios. We verified that sex determin ...

Springer Nature2017

Radiologic evaluation of lumps in the male breast

Mats Julius Stensrud

BackgroundGynecomastia has a typical appearance on mammography, and occurs frequently in men. However, imaging is often performed on men with breast lumps to exclude breast cancer, which only comprises 1% of male breast masses.PurposeTo assess whether ultr ...

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Explores nuclear receptors, JAK-STAT pathway, growth factors, endocrine disruptors, and estrogen receptors.