Pitfalls of conventional human chorionic gonadotropin stimulation test to detect hormonally functional cryptorchid testes in midchildhood.

OBJECTIVE

To report two cases misdiagnosed as bilateral anorchism in midchildhood on the basis of multiple conventional human chorionic gonadotropin (HCG) stimulation tests and sonograms of the abdomen and pelvis.

METHODS

In two young male patients with cryptorchidism who were considered to have anorchism, we describe the findings on clinical examination, the testosterone levels before and after standard HCG stimulation testing, and sonographic findings during the midchildhood period. In both cases, as the children approached puberty the diagnosis was found to be incorrect.

RESULTS

Two boys, 8 and 91/2 years old, were seen in consultation in our Pediatric Endocrine Clinic with a presumed diagnosis of anorchism. In the first case, multiple conventional HCG stimulation tests were done. In the second case, a single stimulation test was performed during routine follow-up assessments. In both cases, testosterone levels before and after HCG stimulation were consistent with the diagnosis of absent functional testicular tissue. Sonograms of the abdomen and pelvis also failed to detect the testicles. Both patients were ultimately noted to be pubertal (at 14 1/2 and >13 1/2 years, respectively) and to have early pubertal testosterone levels. A testicle was detected in one patient by abdominal computed tomographic scan and in the other by palpation of the inguinal canal.

CONCLUSION

Conventional dosing and duration of the HCG stimulation test, as widely recommended in standard textbooks and in articles in the medical literature, may not elicit positive HCG-induced testosterone responses during midchildhood for detection of functional testicular tissue. During the midchildhood period, which is characterized by low gonadotropin, low sex steroid production, and a highly sensitive hypothalamic-pituitary-gonadal axis to feedback inhibition, a prolonged HCG stimulation test-perhaps of 4 to 6 weeks' duration-may be necessary. In addition, other investigational modalities may need to be used to detect the presence of functional testicular tissue during this developmental period.