PREMATURE THELARCHE - A LONG-TERM FOLLOW-UP

The differentiation between premature thelarche and idiopathic central precocious puberty is essential for both long-term prognosis and ther apeutic approach but, until now, there have been insufficient data to predict the future of the girls with premature thelarche. We studied 4 6 girls with premature thelarche longitudinally. The girls weve subdiv ided into two groups according to the time of onset of thelarche: Grou p A consisted of 26 girls who presented thelarche before the second ye ar of life (mean +/- SD 14.7 +/- 5.2 months) and Group B contained 20 girls who showed breast enlargement after the second year of life (5.7 +/- 3.1 years). The mean basal follicle-stimulating hormone (FSH) lev el of the patients as a whole was significantly higher than normal val ues (2.1 +/- 0.05 vs 0.7 +/- 0.9 mIU/ml, p < 0.01) and the luteinizing hormone (LH) level was not significantly different form that in healt hy control subjects (0.8 +/- 0.6 vs. 0.6 +/- 0.7 mIU/ml). After gonado tropin-releasing hormone test the FSH response was significantly highe r than normal prepubertal values (12.9 +/- 2.1 vs. 3.9 +/- 2.9 mIU/ml, p < 0.001) whereas the LH response did nor differ significantly (1.8 +/- 0.6 vs. 1.7 +/- 0.9 mIU/ml. After a follow-up time ranging from 5. 1 to 7.8 years (mean +/- SD 5.9 +/- 1.9) we observed a greater percent age of disappearance in the girls in Group A than in those in Group B. The present data show that the percentage of girls who developed prec ocious puberty was significantly higher when they presented thelarche after the age of 2 years than before; the age of onset of thelarche ca n be useful to distinguish patients at risk of progressing towards pre cocious puberty.