Prepubertal gynaecomastia: aetiology, course and outcome

Abstract

Background: Palpable and measurable glandular breast tissue is a rare finding in prepubertal boys and warrants thorough evaluation to rule out an underlying pathology.

Objective: To characterize the course and outcome of prepubertal gynaecomastia, examine its effect on puberty, and try to identify its underlying cause.

Patients and methods: Twenty-nine out of 581 (5%) boys referred to our clinic for evaluation of gynaecomastia between 1980 and 2000 were prepubertal at diagnosis. Data on age at appearance of gynaecomastia, general and endocrine evaluation, course of growth and puberty, and treatment were collected from the medical files.

Results: Prepubertal gynaecomastia was diagnosed at mean age of 8.9 +/- 2.2 years. In 27 of the 29 boys (93.2%) no underlying cause was identified. The remaining two boys (6.8%) had hyperaromatase syndrome. Nine boys (31%) were obese. Spontaneous resolution was recorded in six boys (20.5%), no change in 15 (52%), and further breast enlargement in eight (including the two with hyperaromatase syndrome) (27.5%). Accelerated growth and bone maturation rates were noted only in the two boys with hyperaromatase syndrome. Pubertal onset was documented in 13 boys at 11.8 +/- 1.1 years.

Conclusions: According to our large single tertiary care centre experience, 5% of boys referred for evaluation of gynaecomastia were prepubertal. The development of gynaecomastia was the only abnormality and was not associated with other pubertal signs or accelerated growth rate. In most cases, the gynaecomastia was idiopathic. Further prospective studies are needed to evaluate the pathophysiological mechanisms responsible for this phenomenon.