Gynecomastia (synonyms: Male mammary gland hyperplasia; Male mammary gland hypertrophy; Massive puberty-related mammary hypertrophy; Puberty mammary hypertrophy; Senile mammary gland hypertrophy; Senile mammary hypertrophy; Overdevelopment of the male mammary gland; Overdevelopment of the male mammary; ICD-10-GM N62: Hypertrophy of the mammary [breast] gland) refers to a palpable, unilateral or bilateral (unilateral or bilateral), and in some cases painful, enlargement of the male mammary gland. It is a benign (benign) proliferation of the glandular tissue.
A distinction is made between “true” and pseudo-gynecomastia:
- True gynecomastia – usually bilateral hypertrophy of the mammary gland.
- Pseudo-gynecomastia (lipomastia) – caused by fatty growth (unilateral) or obesity (obesity) (bilateral).
- Lipo-gynecomastia as a mixed type
Gynecomastia is caused by excessive estrogen action or estrogen-testosterone imbalance.
Physiological gynecomastia occurs in about 90% of male newborns (neonatal gynecomastia) and in about 40-70% of all boys at puberty (pubertal gynecomastia). Pubertal gynecomastia occurs in approximately 60% with a peak in frequency at approximately 14 years of age. Both forms of physiological gynecomastia are reversible (= reversible gynecomastia). Pubertal gynecomastia usually regresses spontaneously within 2 to 3 years (< 5% persist).
Idiopathic gynecomastia is present in approximately 50% of pathologic gynecomastia.
Frequency peak: gynecomastia becomes increasingly common with increasing age and body mass index (BMI).
The prevalence (disease incidence) is 30-60% of the adult male population with an age peak in senility (old age).Up to 90% of male newborns develop reversible gynecomastia. At puberty, the prevalence is 40-70%.
Course and prognosis: Gynecomastia can be physiological in different phases of life – in infants, in puberty, in senility (old age) or a sign of a pathological (pathological) change (= pathological gynecomastia). Therapy is cause-related and must take into account the patient’s psychological distress caused by the female appearance.
