UNILATERAL GYNAECOMASTIA IN PREPUBERTAL BOYS

Abstract

Gynaecomastia is a common feature in pubertal boys. However, gynaecomastia in prepubertal boys, outwith the neonatal period, is unusual in the absence of significant pathology. Unilateral gynaecomastia is rare. Three prepubertal boys (age range 8-11yrs;testicular volume<4mls) with medically significant (Tanner stage 3-4) & socially 6 emotionally unacceptable unilateral gynaecomastia presented to a regional paediatric endocrine service over a period of 5 months. Their anthropometric data were normal and appropriate for parental data; physical examination revealed no other abnormality & there was no history of drug ingestion or similar history in other male family members. Bone ages were appropriate for chronological ages & chromosome analysis was normal. Endocrine investigations including LH, FSH, LHRH, HCG and synacthen stimulation tests, urinary steriod metabolite studies, TSH, T4, PRL & sensitive oestradiol levels were normal(<30pmol/l). Radiological investigations failed to show any hepatic, gonadal, adrenal or hypothalamo-pituitary lesions. All the boys had breast reduction procedures via the subareolar route with good resulte. Breast tissue histology was normal & oestrogen receptor studies are underway. We speculate that unilateral gynaecomastia reflects differences in oestrogen receptor sensitivity between the breast tissue on both sides.