Published on 21/03/2015 by admin
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Chapter 19 GYNECOMASTIA
Theodore X. O’Connell
Gynecomastia, the occurrence of mammary tissue in the male, is a common condition. True gynecomastia, the presence of glandular breast tissue, should be distinguished from pseudogynecomastia, which is simply adipose tissue seen in overweight boys. Gynecomastia is considered the result of an imbalance between estrogens and androgens.
Gynecomastia occurs in three distinct peaks throughout the life cycle. The first is found in the neonatal period, in which palpable breast tissue transiently develops in 60% to 90% of all newborns because of the transplacental passage of estrogens. The effect disappears in a few weeks. The second peak occurs during puberty, when approximately two thirds of boys develop various degrees of subareolar hyperplasia of the breasts. A rise is seen beginning at approximately the age of 10 and peaks between the ages of 13 and 14, followed by a decline during the late teenage years. Tenderness of the breast is common but transitory. Spontaneous regression may occur within a few months, and gynecomastia rarely persists longer than 2 years. The last peak is found in the adult population, with the highest prevalence among 50- to-80-year-olds.
Benign, self-limited, and usually transitory gynecomastia has been reported in prepubertal children during the initiation of therapy with human growth hormone (HGH). Occasionally, breast development may mimic female breast development and fails to regress, as has been reported in familial gynecomastia. Asymmetric gynecomastia is common, and unilateral gynecomastia may actually represent a stage in the development of bilateral disease.
Prepubertal gynecomastia is uncommon, so an exogenous source of estrogens must be sought. Pathologic causes should be considered. However, a specific cause is rarely identified, and in 90% of patients, prepubertal gynecomastia is labeled idiopathic. Accidental or therapeutic exposure to small amounts of exogenous estrogens by inhalation, percutaneous absorption, or ingestion may cause gynecomastia. Gynecomastia has been observed in children with congenital virilizing adrenal hyperplasia, with Leydig cell tumors of the testes, and with feminizing tumors of the adrenal gland. Gynecomastia also occurs in patients with Klinefelter syndrome, certain types of male pseudohermaphroditism, androgen insensitivity syndromes, and 17-ketosteroid reductase defect.
In patients with Klinefelter syndrome, the risk of breast cancer is 16 times higher than in other men. Male breast cancer is rare, and it is even rarer in the adolescent population but warrants mention. Male breast cancer usually presents as a unilateral eccentric mass, hard or firm, that is fixed to the underlying tissues. It may be associated with dimpling of the skin, retraction or crusting of the nipple, nipple discharge, or axillary lymphadenopathy.
Amiodarone
Anabolic steroids
Angiotensin-converting enzyme inhibitors
Calcium-channel blockers
Chemotherapy agents
Cimetidine
Cisplatin
Clomiphene
Diazepam
Diethylstilbestrol
Digoxin
Efavirenz
Estrogens
Ethionamide
Etomidate
Finasteride
Flutamide
Furosemide
Gonadotropins
Growth hormone
Haloperidol
Isoniazid
Ketoconazole
Melatonin
Methadone
Methotrexate
Instant Work-ups A Clinical Guide to Pediatrics
