The aim of this study was to evaluate the usefulness of basal measurements of gonadotropins in distinguishing between constitutionally delayed puberty (DP) and hypogonadotropic hypogonadism (HH), comparing its diagnostic efficiency with that of the dynamic GnRH infusion test (0.83 microg/min during 120 min). We studied 20 males, chronological age (CA) 14-18 years, with a final diagnosis of DP (n = 8), partial HH (n = 5) and complete HH (n = 7), confirmed by follow-up. We also evaluated basal samples of ultrasensitive LH and FSH in 117 healthy control males (CA 2-19 yr), classified according to Tanner stage. In the control group, ROC plot analysis showed a cutoff to differentiate prepuberty from puberty of 0.65 IU/l for LH (sensitivity: 91%, specificity: 98%). Differences were found (p < 0.05) in basal LH and in maximal responses to GnRH in complete HH in relation to DP and partial HH. The diagnostic efficiency of the GnRH infusion test was 85%. For basal LH, a cut-off limit of 0.65 IU/l showed a diagnostic efficiency of 85% for complete HH and 100% for partial HH and DP. We conclude that, in our experience, basal LH levels above 0.65 IU/l measured by ultrasensitive assay would rule out a complete deficiency. It was not possible to differentiate DP from partial HH, either in basal samples or with the infusion test.

In 26 patients with varicocele, measurements of plasma follicle stimulating hormone (FSH), luteinising hormone (LH), testosterone (T) and oestradiol2 (E2) were made; pre-operative and post-operative sperm counts, dynamic stimulation tests with HCG and clomiphene, and testicular biopsies including light microscopy, morphometry, and ultrastructural study in 4 cases, were also performed. A correlation was found between the hormonal pattern and testicular morphology.

Objective: To study hormonal and histological parameters of paediatric±adolescent varicocele in order to know certain aspects of its natural history, in an attempt to find prognostic markers of testicular damage. Design and methods: In a prospective cross-sectional study, we evaluated 93 children and adolescents with left unilateral varicocele and 29 healthy males as control group. All of them were classified according to Tanner stage. Scrotal Doppler in both testes and GnRH and human chorionic gonadotrophin (hCG) tests were performed in all subjects. Surgery was performed in 28 patients and homolateral testicular biopsy in 18. Results: Hormonal measurements of patients with varicocele were compared with a control group for each Tanner stage. Testicular biopsy specimens were analysed by light and electron microscopy. We only observed statistical differences in Tanner III patients in basal FSH (median and range) controls 1X70 (1.10±3.70) IU/l vs varicocele 4X20 (1.00±7.50) IU/l, P , 0X05 and in Tanner IV patients in LH post-GnRH: controls 11X0 (7.50±15.0) IU/l vs varicocele 18X0 (5.10±29.0) IU/l, P , 0X05 and in testosterone post-hCG: controls 9X50 (7.7±10.0) ng/ml vs varicocele 12X0 (6.2±23.0) ng/ml, P , 0X01X No correlation was found between the various clinical grades of varicocele and hormonal measurements for each Tanner stage. No statistically significant differences were found between pre-and post-operative hormonal findings, either in basal levels or in maximal responses. On the other hand, no morphological abnormalities were observed by electron microscopy in germ cells, tubular wall and interstice.Conclusions: There appears to be no reliable biochemical marker in children and adolescents that may predict impaired testicular function. A significant size discrepancy between both testes, testicular pain and a hyperresponse to GnRH stimulation should continue to be, for the time being, the indications for surgery.

PRL response to domperidone allowed us to characterize hyperprolactinemias, although the presence of a blunted response should be confirmed in a larger number of patients with tumors with 'low' PRL levels (dependence on etiology or basal PRL level?).