Serum gonadotropins in cryptorchidism. An indicator of functional testes

Pediatric testicular problems

Testicular problems in children may be both congenital and acquired. These problems are often difficult to diagnose and carry significant sequelae if untreated. Early surgical consultation is often needed for correction of the problem. This article reviews the pathophysiology of the most common pediatric testicular abnormalities with emphasis on the diagnostic modalities employed and current treatment alternatives.

The assessment of diminished testicular function in boys of pubertal age

Nine boys with anorchia and 9 individuals with diminished testicular function were followed between ages 10 and 18 with serial determinations of urine gonadotrophins and serum testosterone. Ten hCG stimulation tests were performed in eight of these patients. Adult levels of LH (greater than 500 mIU/h) and low measurements of serum testosterone (less than 54 ng/dl) confirmed the anorchic state. Boys with diminished testicular reserve exhibited urinary gonadotrophin changes similar to peripubertal anorchic patients but testosterone levels increased progressively with age (90-715 ng/dl). FSH attained adult castrate levels (greater than 1700 mIU/h) by age 13 in these boys and served to distinguish them from normal controls. The longitudinal assessment of basal hormone levels can separate anorchia from diminished testicular reserve in boys of pubertal age and testing with hCG is not required for evaluation.

Testicular and sexual function in adults with prune belly syndrome

Testicular and sexual function was investigated in 9 patients between 16 and 28 years old with prune belly syndrome. At personal interview all patients claimed to experience normal erections and orgasm but 7 had retrograde ejaculation. Examination showed a normally developed male habitus. Orchiopexies had been performed in late childhood or adolescence. Two patients were anorchic and the surviving testicles were small in the remaining 7. Serum testosterone was low in 1 patient and normal in 6 but at the expense of high luteinizing hormone levels in 4. All patients had a high serum follicle-stimulating hormone level, reflecting the azoospermia found in 5 patients tested. Three biopsies from atypical cases showed poor histological findings but 2 revealed early spermatogenesis. The testes in patients with prune belly syndrome are similar to undescended testes in otherwise normal men. Late orchiopexy produces sexually active but infertile men.

Endocrine profiles in pediatric andrology. III. Human chorionic gonadotropin stimulation test in cryptorchid boys

Serum testosterone (T) concentration and urinary 17-ketosteroid (17-KS) excretion were measured under basal conditions and after stimulation with human chorionic gonadotropin (hCG) in 36 prepubertal males (10 normal children and 26 cryptorchid patients). As a function of hCG stimulation, the increase in serum T level was evident in both groups, although the magnitude of the rise was higher in the control group than in cryptorchid boys. No significant differences in serum T or urinary 17-KS were observed between patients with unilateral and bilateral undescended testis, either before or after hCG stimulation. In spite of the wide individual variations in testicular response in all subjects, the test is valuable in assessing Leydig-cell function and in prognosis for virilization at puberty.

The use of computerized tomography scanning to localize the impalpable testis

To determine the usefulness of computerized tomography scanning in the preoperative localization of the impalpable undescended testis 5 patients with 8 impalpable testes were studied. In 2 patients the scan correctly outlined 3 impalpable testes inside the internal inguinal ring, in 2 patients the scan correctly localized 4 impalpable testes at or just inside the external inguinal ring and in 1 patient the scan failed to demonstrate a testis, a finding corroborated at an operation. These results suggest that computerized tomography scanning appears to be an effective, simple and less hazardous method to localize impalpable undescended testes than other currently available techniques.

Follicle-stimulating hormone. IV. Study of the histology of pubertal cryptorchid and scrotal testes in relation to the secretion of gonadotropins

The morphologic characteristics of 85 cryptorchid and 63 contralateral (scrotal) testes showing histologic changes of puberty were studied. Spermatogenesis was not only delayed on the cryptorchid side but also hypocellular in all cases. The scrotal testes appeared hypocellular in 82.5% of the cases. Repetitive biopsies, performed in 12 patients, showed no improvement of cellularity after orchidopexy but progress in pubertal maturation. In the 22 boys submitted to luteinizing hormone-releasing hormone (LH-RH) stimulation, luteinizing hormone (LH) baseline values did not change significantly whereas follicle-stimulating hormone (FSH) baseline levels increased with advancing age and histologic stage of maturation. LH responses increased with the stage of maturation (without statistical significance); however, LH responses were significantly higher in the group without germ cells. FSH responses to LH-RH stimulation were consistently and significantly higher with advancing stages of maturation and in the group without cells.

Sleep-wake patterns and integrated values of luteinizing hormone, follicle stimulating hormone, prolactin, growth hormone and thyroid stimulating hormone in normal and cryptorchid pubertal patients

The sleep-wake behaviour of LH, FSH, PRI, GH and TSH was studied in seven cryptorchid patients (four unilateral and three bilateral cryptorchids) average age 12 years and in nine normal pubertal boys of 13 years (mean age). Blood samples were collected by a continuous withdrawal pump, every hour, for 24 h. The hormonal concentration for every fraction of time was measured and related to the sleep (Sc-), wake (Wc-) and total 24 h period (Dc-). The integrated concentrations of the corresponding periods (IS, IW, ID) were calculated as well as their ratios (IS/IW; IS/ID%). For GH and TSH, the data obtained demonstrated no differences between cryptorchid and pubertal subjects. The PRL secretion in cryptorchid patients was moderately increased during the hours of nocturnal sleep. A normal pubertal sleep-wake rhythm was found for gonadotrophins in both groups of subjects. More marked levels of LH secretion were observed in cryptorchid boys compared to normal pubertals. The presence of a sleep-wake rhythm was also found in the cryptorchid patients and normal pubertal subjects in the P 1 stage. These data suggest that the CNS "programme" which controls the onset of puberty may be normal in cryptorchid patients.

Unilateral abdominal cryptorchidism

The unilateral non-palpable undescended testis is considered separately from other forms of cryptorchidism. It is less likely to be fertile, it is more prone to malignancy and it is more difficult to place. Removal rather than orchiopexy often is in the best interests of the child.

Testicular function following irradiation of the human prepubertal testis

Testicular function was studied in ten men, aged between 17 and 36 years, who had received irradiation for a nephroblastoma during childhood. The dose of scattered irradiation to the testes ranged from 268 to 983 rad. Eight subjects had either oligo- or azoospermia (0 to 5.6 million/ml), seven of whom had an elevated serum follicle-stimulating hormone (FSH) level. One subject showed evidence of Leydig cell dysfunction with a raised serum luteinizing hormone level (LH) and a low plasma testosterone concentration. A second group of eight prepubertal males, aged between 8 and 14 years, were studied. These had also been irradiated for abdominal malignancies during childhood and received a similar dose of irradiation to the testis as the first group studied. The plasma testosterone levels were within the normal range for prepubertal boys in all eight. The mean gonadotrophin levels were not significantly different from the mean levels of normal prepubertal males. Thus irradiation-induced damage to the germinal epithelium in prepubertal boys produces raised FSH levels after puberty but not before it. We conclude, therefore, that inhibition has a minor role in the control of the prepubertal hypothalamic-pituitary testicular axis and its contribution to gonadal control of gonadotrophin secretion changes with sexual maturation.

Gynecomastia and gonadal dysfunction in adolescent boys treated with combination chemotherapy for Hodgkin's disease

We studied 19 Ugandan boys with Hodgkin's disease who had been treated with mechlorethamine, vincristine, procarbazine and prednisone and who survived at least two years to assess testicular germ-cell depletion in pubescent boys on combination chemotherapy, as had previously been demonstrated in sexually mature men. Nine of 13 pubertal boys (ages 11 to 16) had moderate to severe gynecomastia and germinal aplasia, a 10-fold increase in mean (+/- S.D.) serum follicle-stimulating hormone (34.8 +/- 20.5 mlU per milliliter), a threefold increase in mean luteinizing hormone (17.8 +/- 9.8 mlU per milliliter) and reduced serum testosterone levels. Gynecomastia was not associated with an increase in either serum estradiol or prolactin concentrations. By contrast, six prepubertal boys (three to 10 years of age), similarly treated, showed no change in serum gonadotropins, and gynecomastia did not develop. The data confirm germ-cell depletion after combination chemotherapy and indicate further that Leydig-cell dysfunction, manifested by gynecomastia, may be a consequence of treatment in adolescent boys.

Evaluation of testicular function in prepubertal boys by means of the luteinizing hormone-releasing hormone test

Luteinizing hormone (LH)-releasing hormone (LH-RH) tests (50 microgram/sq m intravenously) were performed in 112 prepubertal boys ages 13/12 to 11 years (mean +/- standard deviation, 75/12 +/- 16/12 years) suspected of having a testicular disorder because of improperly located testes (77 boys) or hypogonadism (35 boys). Four of the patients were retested within a period ranging from 6 to 16 months. Of the 112 boys tested, 17% were found to have high basal levels of follicle-stimulating hormone (FSH) and 23% were found to have an abnormally high release of FSH after LH-RH administration. Only three patients had abnormally high basal levels of LH and/or elevated LH responses to LH-RH. The basal plasma testosterone levels were found to be normal in all 112 bosy. The fact that plasma FSH levels were elevated more often than LH levels suggests that the tubular elements are damaged more frequently than are the Leydig cells. The surprisingly high incidence of an abnormal response of plasma FSH to LH-RH in boys with mobile testes calls for an increased awareness of the importance of regular examination of these patients until full puberty has been achieved. It is concluded that determination of basal plasma FSH levels and the response to LH-RH stimulation is a useful diagnostic tool for evaluating testicular function in prepubertal boys with suspected pathology of the testes.

Endocrine tests in phenotypic children with bilateral impalpable testes can reliably predict "congenital" anorchism

Congenital anorchism is a rare condition. Bilateral impa-pable undescended testes are relatively common by comparison. Surgical exploration has been regarded as the final arbiter between anorchism and bilateral cryptorchism. Exploration has not proved completely reliable in making this differentiation. Endocrine studies, particularly the human chorionic gonadotropin (HCG) stimulation test together with measurements of basal plasma gonadotropins, can reliably exclude "functioning" testicular tissue. Eleven fully evaluated and operated cases support this contention. In the specific clinical setting of a normal phenotypic male child with a 46XY karyotype and no müllerian structures palpable on rectal examination, nonfunctioning testes on endocrine testing means congenital anorchism and surgical confirmation is unnecessary. In contradistinction, a positive HCG test would appear to mandate through and extensive surgical exploration.

Hormonal regulation of testicular descent: experimental and clinical observations

Hormonal regulation of testicular descent has been investigated. Based on experimental studies using the rat and on a review of clinical material it has been determined that testicular descent is an androgen-mediated event directly under the regulation of pituitary gonadotropin. Furthermore, the active androgenic metabolite involved in this process appears to be dihydrotestosterone, which is synthesized by the testis and must be present in high local concentrations to be effective. In addition to these hormonal requirements the anatomy of the inguinal canal must provide unimpeded migration of the testis into the scrotum. Any imbalance or anomaly of these prerequisites may lead to cryptorchidism.

Male pseudohermaphroditism due to steroid 5-alpha-reductase deficiency

A new inherited form of male pseudohermaphroditism has been investigated in a pedigree of 24 families with 38 affected males. At birth, the affected males (46 XY) have a clitoral-like phallus, bifid scrotum and urogenital sinus. The testes are in the inguinal canals or labial-scrotal folds. The Wolffian structures are normally differentiated; there are no Mullerian structures. At puberty a muscular male habitus develops with growth of the phallus and scrotum, voice change and no gynecomastia. The subjects have erections, ejaculations and a libido directed towards females. They have decreased body hair, a scant to absent beard, no temporal hair line recession and a small prostate. Testicular biopsy reveals a normal testis. The mean plasma T levels in affected adults are significantly higher, and the mean plasma DHT levels are significantly lower when compared to those in normal subjects. The plasma T:DHT ratios range from 35 to 84 compared to 8 to 16 in normal subjects. After the administration of hCG, the T:DHT ratios in affected male children range from 74 to 162 compared to 3 to 26 in the control subjects. In affected adults, mean plasma LH and FSH levels are significantly higher than in normal subjects. In the affected subjects, the metabolic clearance rates of T and DHT are normal, but the conversion ratio of T to DHT is less than 1 per cent. The endogenous mean urinary E:A and E-OH:A-OH ratios, and the urinary E:A and E-OH:A-OH ratios after the infusion of radioactive T are significantly higher than in normal males. Inheritance is autosomal recessive with some sibling sisters showing the same biochemical defect, and obligate carrier parents showing an intermediate defect. These data support our thesis that the defect in these male pseudohermaphrodites is secondary to decreased steroid delta 4-5 alpha-reductase activity. The affected subjects provide a clinical model for delineating the roles of T and DHT in sexual differentiation and development. This entity also demonstrates an inherited disorder of steroid metabolism in which the basic enzyme deficiency resides in the target tissues.

Endocrinological studies in undescended testes

A cross-sectional study was carried out on 168 boys aged 2.5-16.8 years with unilateral or bilateral testicular maldescent. Urinary excretion of testosterone, delta4-androstenedione, LH and FSH was investigated. The results were related to chronological age, bone age and sexual maturation stage. Urinary testosterone excretion was elevated in unilateral and bilateral cases of undescended testis under 9 years of age. The pubertal increase of testosterone excretion seemed to be moderately delayed in the patients. In pubertal stage V the testosterone excretion was normal. The mean testosterone/androstenedione relationship was normal in all age groups up to 14.9 years and increased in patients above this age. After HCG stimulation, the testosterone excretion increased at all ages studied whereas the androstenedione excretion increased only in bilateral cases under 11 years of age. Urinary LH excretion was diminished in bilateral cases aged 6.0-7.9 years and elevated in unilateral cases in pubertal stage V. Urinary FSH excretion was normal below 8 years of age, moderately elevated in bilateral cases aged 8.0-11.9 years and increased in unilateral cases in pubertal stage V. Patients with bilateral anorchia in pubertal stage I, had normal basal testosterone and androstenedione excretion while the LH and FSH levels were increased. The findings in this study indicated that disturbances in the pituitary-gonadal function of cryptorchids might be operative from early childhood and throughout pubertal years.

Treatment of cryptorchidism. Long-term prospective study

We have presented preliminary findings on a long-term prospective study designed to (1) assess timing of orchiopexy, (2) eliminate unnecessary abdominal exploratory surgery, and (3) determine efficacy of orchiopexy on subsequent fertility and on malignant degeneration. Some suggestions for the management of this common congenital defect can be provided, but long-term results are lacking. A significant drop-out rate from this prospective study is expected with time; therefore, large patient numbers are needed to draw any valid conclusions at the time of postpubertal reassessment.