Hypothalamic-pituitary-testicular axis evaluation in boys presenting with nonpalpable gonads during infancy, childhood or puberty.

GRINSPON R; BEDECARRÁS P; ROPELATO MG.; REY R.; GOTTLIEB S.

Lyon, Francia

Congreso; ESPE/LWPES 7th Joint Meeting Paediatric Endocrinology; 2005

ESPE/LWPES

The assesment of the presence and functional capacity of the testes is essential in the evaluation of boys with virilization and nonpalpable gonads. Surgical procedures are invasive and imaging techniques may not be accurate. Hormonal evaluation is therefore indispensable. Anti-Müllerian hormone (AMH) and testosterone (T) measurement is used to assess the functional capacity of the tubular compartment, regulated by FSH, and the interstitial tissue, regulated by LH, respectively. An integral analysis of the whole pituitary-testicular axis might be more informative in the diagnosis of boys with nonpalpable gonads. We evaluated the levels of FSH (IFMA), AMH (ELISA), LH (IFMA) and T (RIA) in samples of 6 boys 0-6 months-old, 39 prepubertal (>6 monthsold) and 7 pubertal, with normal virilization but nonpalpable testes. Clinical charts of all patients included were thoroughly reviewed. Absence of functional testicular tissue was diagnosed when AMH was non detectable and T was not >50 ng/dL (post-hCG or basally in patients with elevated LH). Four anorchid patients <6 months-old had elevated FSH (40—199 IU/L) and LH (40-92 IU/L) and low T (<10-17 ng/dL). The other 2 patients, with present testes, had low FSH, AMH, LH and basal T with normal response to hCG test. Twelve of the 39 prepubertal patients were anorchid: in 9 both FSH (3.4- 130 IU/L) and LH (0.5-25 IU/L) were elevated; in 2, FSH but not LH was elevated, and in 1 both gonadotropins were normal. The remaining 27 prepubertal boys had testicular tissue. In 18 cases, testes were hypofunctional, resulting in low AMH and/or poor T response to hCG. Gonadotropins were elevated in 7 and normal in 11. In 9 cases, testes were functionally normal. Five of the 7 pubertal patients were anorchid: in 4 both FSH (24-99 IU/L) and LH (15.6-28.6 IU/L) were high and in 1 only FSH was elevated. The remaining 2 patients had testicular tissue: T was normal but gonadotropins were elevated. We conclude that absence of gonads can be diagnosed by measuring either basal FSH (high) or AMH (ND) or T post-hCG (low) in 95% of cases. Conversely, for the diagnosis of presence and functional capacity of testes, AMH and T are more helpful.