[Complete isosexual precocious puberty: clinical, pelvic ultrasound and laboratory features].

OBJECTIVE

To determine whether initial presentation varies according to aetiology, whether such differences allow differential diagnosis between idiopathic and organic forms, and whether CNS imaging can be avoided in some patients with central precocious puberty (CPP).

PATIENTS AND METHODS

Children referred for evaluation of precocious puberty were evaluated, and the subpopulation of children with CPP was enrolled in this prospective observational study. Clinical, laboratory and ultrasound features of 62 consecutive patients with CPP (5 boys and 57 girls) were recorded. We compared the characteristics of idiopathic (3 boys, 49 girls) and organic (2 boys, 8 girls) CPP.

RESULTS

There were no differences in pubertal staging, age at puberty onset (7.0 [5.8-7.5] vs. 7.3 [5.1-8.3] years), bone age/chronological age ratio (1.26 [1.2-1.3] vs. 1.23 [1.1-1.3]), maternal menarche (11.7+/-0.2 vs. 11.7+/-0.6 years) between idiopathic and organic CPP, respectively. Organic CPP patients had a poorer height SD (0.35+/-0.4 vs. 1.6+/-0.1; p<0.01), predicted adult height, growth rate and growth rate SD (0.8+/-0.9 vs. 3.7+/-0.7). Girls with organic CPP had significantly higher oestradiol levels (47.5 [25-68] vs. 27 [14-43] pg/ml) than girls with idiopathic CPP. Pelvic ultrasound at the time of diagnosis revealed the presence of pubertal changes in internal genitalia in 43.9% of girls (37.2% idiopathic versus 62.5% organic CPP subpopulation; p=0.18).

CONCLUSIONS

There is a clinical-ultrasound overlap between idiopathic and organic CPP. Imaging remains necessary in all cases of central precocious puberty, and ultrasound data should not be replaced by other diagnostic investigations.