Abnormal germ cell development in cryptorchidism.

BACKGROUND: Previous studies suggest that two fundamental, probably androgen-dependent, steps in maturation of germ cells normally occur in the prepubertal testis: the disappearance of gonocytes (the fetal stem cell pool) and the appearance of adult dark spermatogonia (the adult stem cell pool) at 2-3 months of age and the appearance of primary spermatocytes (the onset of meiosis) at 4-5 years. Previous studies of small series of cryptorchid boys suggest that both steps are defective in undescended testes and to a lesser degree in descended testes contralateral to unilaterally undescended testes. The purpose of this study is to confirm the previous findings of defective germ cell maturation in a large series of boys with unilateral undescended testes. PATIENTS: Seven hundred and sixty-seven boys with unilateral cryptorchidism who had orchidopexy and bilateral testicular biopsies between birth and 9 years of age were studied. MATERIALS AND METHODS: Total and differential germ cell counts were performed on semithin histologic sections of the biopsies. The results from the undescended and contralateral descended testes were compared using the Wilcoxon signed-rank test and the Wilcoxon-Whitney-Mann U test. RESULTS: Gonocytes failed to disappear and adult dark spermatogonia failed to appear in undescended testes under 1 year of age indicating a defect in the first step in maturation at 2-3 months resulting in failure to establish an adequate adult stem cell pool. Primary spermatocytes failed to appear in undescended testes and appeared in only 19% of contralateral descended testes at 4-5 years of age indicating a defect in the onset of meiosis. CONCLUSION: Unilaterally undescended testes fail to establish an adequate adult stem cell pool which normally occurs at 2-3 months of age and fail to establish adequate meiosis which normally occurs at 4-5 years of age. Similar but less severe changes are seen in the contralateral descended testes. Defects in the two pubertal steps in germ cell maturation are associated with reduced total germ cell counts.

Hormonal therapy for the subfertility of cryptorchidism.

BACKGROUND: The subfertility of cryptorchidism correlates with severely reduced total germ cell counts in prepubertal testicular biopsies of undescended testes. Reduced total germ cell counts are associated with defects in the two prepubertal steps in maturation and proliferation in germ cells: first, the transformation of the fetal stem cell pool (gonocytes) into the adult stem cell pool (adult dark spermatogonia) at two to three months of age and, second, the transformation of adult dark spermatogonia into primary spermatocytes (meiosis) at 4-5 years. The defects in maturation are associated with blunting of the normal surges in gonadotropins and testosterone. Prepubertal treatment with gonadotropin-releasing hormones would theoretically trigger normal germ cell maturation and proliferation and thereby improve total germ cell counts and improve fertility. Prepubertal treatment of cryptorchidism with the GnRH analogue Buserelin has resulted in improved total germ cell counts and improved spermiograms. The purpose of this report is to describe the results of treatment of cryptorchidism with the GnRH analogue Naferelin. PATIENTS: Twelve boys with cryptorchidism, 6 unilateral and 6 bilateral, and severely reduced germ cell counts in testicular biopsies were treated with Naferelin following successful orchidopexy and bilateral testicular biopsies. Response of the total germ cell counts was assessed in follow-up bilateral biopsies within 5 months of completing the hormonal therapy. RESULTS: Eight of the 12 boys (5 of the 6 with unilateral and 3 of the 6 with bilateral cryptorchidism) showed improvement in the total germ cell counts in one or both testes. All 8 had a poor prognosis for fertility pretreatment and a good prognosis for fertility posttreatment. Of the 5 with unilateral cryptorchidism who improved, 2 showed improvement in both testes; and 3, only in the contralateral descended testes. All 3 of the boys with bilateral cryptorchidism who improved showed improvement in both testes. Testes with absence of germ cells and older patients tended to show no improvement. Of the 6 contralateral descended, 5 (83%) improved, and of the 18 undescended testes, 8 (44%) improved. CONCLUSIONS: In this preliminary study, Naferelin therapy appears to induce improvement in the total germ cell counts and the prognosis for future fertility in 75% of patients.

The histopathology of iatrogenic cryptorchid testis: an insight into etiology.

PURPOSE: Iatrogenic undescended testis may develop after inguinal hernia repair, presumably as a result of mechanical tethering of the testis or cord in scar tissue. Because some true cryptorchid testes appear to be completely descended at birth and later ascend during childhood, some iatrogenic undescended testes may be low lying undescended testes. To determine whether iatrogenic undescended testes may be unrecognized cryptorchid testes at herniorrhaphy we examined biopsies of iatrogenic undescended testes and the corresponding contralateral descended testis. MATERIALS AND METHODS: Between 1985 and 1999 bilateral testis biopsies were obtained at orchiopexy in 37 boys 1.5 to 11.8 years old who previously underwent inguinal hernia correction. Histomorphometric analysis of germ cell counts was performed on the undescended and contralateral descended testes, and compared to the count in bilateral biopsies of 37 age and position matched patients with true unilateral cryptorchidism. RESULTS: There were no significant differences in volume or total and differential germ cell counts in the undescended and contralateral descended testes in the study groups and age matched controls with primary unilateral cryptorchidism. The mean number of germ cells per tubule in the undescended testis in patients with a greater than 5-year interval from herniorrhaphy to orchiopexy was significantly decreased compared to those with an operative interval of less than 5 years (0.27 +/- 0.33 versus 0.93 +/- 1.4, p = 0.026). CONCLUSIONS: Some patients with iatrogenic undescended testis may have an unrecognized low cryptorchid testis. Careful physical examination before and after inguinal surgery is recommended. The early repair of iatrogenic undescended testis is warranted to prevent further damage.

Abnormal testicular histology in Michelin tire syndrome.

An 8-year-old male is described with Michelin tire syndrome and an abnormal testicular histology which has not previously been reported in this syndrome.

Ectopic and undescended testes: 2 variants of a single congenital anomaly?

PURPOSE: We compared pathological findings in ectopic and undescended testis to determine whether the pathological evidence supports the hypothesis that the 2 conditions are variants of the same congenital anomaly. MATERIALS AND METHODS: We identified 24 boys with ectopic testis not in the superficial inguinal pouch of Denis Browne. Seven boys were excluded from study due to unavailable clinical records for 3, contralateral undescended testis in 2 and inadequate biopsy specimens in 2. Pathological findings of ectopic testis in the remaining 17 patients were compared with those of age matched patients with unilateral undescended testis. Total germ cell count, testicular volume, patency of the processus vaginalis and epididymal abnormalities were compared. Data were analyzed using the Wilcoxon matched pairs signed rank and Fisher's exact tests. RESULTS: No difference was noted in total germ cell count (p = 0.33), testicular volume (p = 0.1475), processus vaginalis patency (p = 0.0854) or epididymal abnormalities (p = 1.00) in the 2 groups. Of the 24 boys (8%) with ectopic testis 2 also had a contralateral undescended testis. CONCLUSIONS: Similar pathological findings in ectopic and undescended testes as well as the association of ectopic testis with a contralateral undescended testis suggest that ectopic and undescended testes are variants of the same congenital anomaly. Thus, boys with ectopic testis may have an increased incidence of subfertility and testicular malignancy. This spectrum of abnormal testicular position, and its range of pathological conditions and complications may appropriately be called the undescended testis sequence.

Testicular volume does not predict germ cell count in patients with cryptorchidism.

PURPOSE: A germ cell count of less than 0.2 germ cell per tubule on the prepubertal biopsy of cryptorchid testes predicts abnormal spermiograms and decreased fertility in adulthood, and may be used to select patients for post-orchiopexy hormonal therapy. Testicular volume directly correlates with testicular function and spermiogenesis. We determined whether testicular volume would predict the total germ cell count accurately enough to replace testicular biopsy in the modern management of cryptorchidism. MATERIALS AND METHODS: At our hospital 723 patients younger than 9 years with cryptorchidism (unilateral in 619 and bilateral in 104) underwent orchiopexy and bilateral testicular biopsies. These patients had not undergone groin surgery or hormonal therapy previously and had at least 50 tubules in each testicular biopsy. Testicular volume and position, patient age and germ cell counts were analyzed. The generalized estimating equation was used to determine whether a correlation existed between testicular volume and germ cell count. RESULTS: The generalized estimating equation demonstrated a direct correlation between testicular volume and germ cell count. However, germ cell counts predicted from testicular volume varied widely within the 95% confidence intervals. Testes with less than 0.2 germ cell per tubule cannot be reliably distinguished from those with greater than 0.2 germ cell per tubule. CONCLUSIONS: Testicular volume does not accurately predict the germ cell count in patients with undescended testes, cannot be used to select patients for post-orchiopexy hormonal therapy and cannot replace testicular biopsy in the modern management of cryptorchidism.

The role of renal salvage procedures for bilateral Wilms tumor: a 15-year review.

PURPOSE: We reviewed our experience with renal salvage procedures in patients with bilateral Wilms tumor to determine the clinical outcome. MATERIALS AND METHODS: From 1982 to 1997, 23 children with bilateral Wilms tumor were treated with partial nephrectomy at our institution, including 7 who were also treated with brachytherapy. Medical history, use and response to chemotherapy and brachytherapy, operative records, renal function, pathological results, survival, and techniques for partial and repeat nephrectomy and brachytherapy were reviewed. RESULTS: We treated 8 boys and 15 girls, of whom 21 who presented with synchronous bilateral Wilms tumor underwent primary chemotherapy followed by secondary partial nephrectomy. A total of 44 partial nephrectomies were performed and brachytherapy was done in 7 patients. Ten children have normal renal function and no disease, 10 are dead and 2 have metastatic disease. Anaplasia was the most significant factor associated with an unfavorable outcome (p = 0.003). Of the patients who were cured 60% had a positive response to initial chemotherapy compared with only 25% who had an unfavorable outcome (p = 0.09). No significant differences were noted with respect to gender, age at presentation, highest local tumor stage at presentation or initial nephrectomy. No patient treated with brachytherapy had local recurrence. CONCLUSIONS: Preoperative chemotherapy followed by nephron sparing surgery is indicated in patients with bilateral Wilms tumor, while in those with diffuse anaplasia nephron sparing surgery is contraindicated. Brachytherapy should be considered for treating local disease involving chemoresistant tumors.

An unusual subset of cryptorchidism: possible end organ failure.

PURPOSE: A paucity of germ cells exists in the cryptorchid gonad that usually correlates with a similar finding in the contralateral descended testis. However, we have noted a small number of boys with cryptorchidism in whom there is a significant difference between the histological evaluation of the cryptorchid testis and the normal descended testis that may indicate a different etiology. MATERIALS AND METHODS: From 1986 to 1991, 1,426 boys with unilateral cryptorchidism underwent orchiopexy, of whom 752 also underwent bilateral testicular biopsy. Testicular volume and position, and patency of the processus vaginalis were examined. Biopsies were fixed in 2% glutaraldehyde and embedded in Epon. Semithin tissue sections were analyzed by 2 independent investigators. The number of total germ cells, gonocytes, adult dark and pale spermatogonia, primary spermatocytes and Leydig cells was assessed. RESULTS: Of the 1,426 boys the undescended testis was on the right side in 726 and on the left side in 658 (52 versus 48%, p = 0068). Of the 752 boys who underwent bilateral biopsy 42 (5.6%) 1.1 to 16 years old (mean age plus or minus standard deviation 0 5.2 +/- 3.65) had a poor fertility index of less than 0.2 germ cell per tubule in the cryptorchid gonad, although the germ cell count in the descended testis was normal. Of the 42 testes in this special group of boys 30 (71%) were on the right side (Fisher's exact test p <0.23), including 16 (38%) in an intra-abdominal or high canalicular position. The processus vaginalis was patent in 86% of the intra-abdominal testes and in 100% of those located at the tubercle but in only 25% of those in a pre-scrotal position. While average germ cell count in the cryptorchid testis was 0.06 per tubule with abnormal germ cell maturation, number was normal (greater than 2 germ cells per tubule) in the contralateral descended testis with a normal distribution of adult dark and pale spermatogonia, and primary spermatocytes. Average volume of the cryptorchid testis was significantly less than that of the descended testis (1.20 +/- 0.35 versus 1.60 +/- 0.68 mm.3, p <0.0001). CONCLUSIONS: Based on the normal scrotal testis the fertility prognosis is good in this small subgroup of boys with cryptorchidism. Rather than the usual endocrinopathy of cryptorchidism, the undescended testis in these boys may be the result of end organ failure. These patients with favorable fertility potential may be recognized only if each testis is biopsied at unilateral orchiopexy.

Magnetic resonance imaging of embryos: an Internet resource for the study of embryonic development.

The recent amassing of gene expression data to study development in mammals has led to an increased demand for access to human embryological data. The difficulty of obtaining well-preserved human embryos presents an important challenge to studying human development. The Multidimensional Human Embryo project is generating an image data set based on magnetic resonance microscopy of specimens from the highly respected Carnegie Collection of Human Embryos. The data are available from a web site to facilitate the work of clinicians, investigators, and students of human development. A consequence of the project will be to preserve a highly respected, yet impermanent, collection of human embryos and minimize the need for collecting new specimens.

Magnetic resonance microscopy of embryos.

We demonstrate that magnetic resonance (MR) microscopy provides a mechanism to investigate normal and abnormal developmental anatomy in a non-destructive and distortion-free manner. Techniques for the fixation, embedding, perfusion and image acquisition of embryos between 3 and 30 mm crown rump length are described. We describe the perfusion of a contrast agent to enhance images of the developing embryonic vasculature. Data are acquired as three-dimensional isotropic arrays which permit images to be reformatted retrospectively in any plane. The data are available for archiving, distributing and for post-acquisition manipulations. MR microscopy is a fast technique for producing three-dimensional reconstructions and is free from registration and sectioning artifacts.

Congenital cytomegalovirus infection in offspring of liver transplant recipients.

There has been an increasing number of women undergoing liver transplantation during their childbearing years. As the number of pregnancies among these women increases, complications during pregnancy and risks to the fetus associated with liver transplantation will be better defined. We report three cases of cytomegalovirus (CMV) infection in offspring of liver transplant recipients. Two of these recipients had preterm labor and gave birth at approximately 23 weeks' gestation; both neonates had clinical (hydrops fetalis), laboratory, and placental evidence of CMV infection. The third recipient gave birth at 26 weeks' gestation because of severe preeclampsia, and the neonate died at 12 days of age of CMV sepsis. Placental CMV infection was confirmed in this case by polymerase chain reaction analysis, which is a valuable tool for prospectively or retrospectively diagnosing this infection. Our findings indicate that CMV infection poses a significant risk to offspring of liver transplant recipients.

The absent cryptorchid testis: surgical findings and their implications for diagnosis and etiology.

On surgical exploration for impalpable testes, there is often found nothing or a nubbin of tissue at the end of the spermatic vessels. This situation is commonly referred to as an absent testis. Controversy exists on how to establish correctly this diagnosis and the degree of investigation required. In addition, there is disagreement concerning whether an absent testis results from early torsion or endocrinopathic event. What is accepted is that the spermatic vessels are singularly important in establishing testis location. In this study, the pathological findings of 117 cases of absent testis diagnosed by surgical exploration at our hospital were reviewed. This diagnosis represented 10% of 1,225 patients explored for cryptorchidism from 1985 to 1991. Average patient age at operation was 26.8 months (range 5 months to 14 years). Of these children 78 (67%) presented with an impalpable left testis. At operation 3 patients (3%) underwent laparoscopy only, while all others had groin exploration with or without transperitoneal exposure to ensure identification of spermatic vessels. In 110 cases surgical specimens or nubbins were excised. Pathological study of these remnants revealed vas deferens in 89 cases (81%), epididymal tissue in 40 (36%) and small amounts of seminiferous tubules with germinal elements in 7 (6.4%). Only 26 specimens (24%) had sufficient vascular tissue present to be suggestive of spermatic vessels. A significant number showed the presence of calcification (35.5%) and hemosiderin (30%) deposits within the remnant. A subset of patients with absent testis possesses testicular tissue of presumed increased malignant potential. Therefore, surgical exploration with spermatic vessel identification and remnant removal is the gold standard for the diagnosis and treatment of the absent testis. The surgeon continues to be responsible for spermatic vessel identification, since the vessels may be recognized at pathological examination in less than 25% of the cases. Also, the common finding of calcification and hemosiderin lends weight to the torsion etiology over endocrinopathy for an absent testis.

Anatomical, morphological and volumetric analysis: a review of 759 cases of testicular maldescent.

Undescended testis is the most frequent disorder of male sexual differentiation affecting 0.8% of all boys by age 1 year. Anatomical and descriptive features of undescended testis lack standardization, and often do not reflect intraoperative findings. We review a large cohort of patients treated for undescended testis and analyze anatomical, morphological and volumetric findings at orchiopexy. Of 759 patients 1 month to 9 years old entered into the study between 1985 and 1990 at our hospital 55% underwent surgery between ages 8 months and 4 years, 15.5% had bilateral undescended testis and 27.6% had a nonpalpable gonad. Preoperative physical findings correlated poorly with intraoperative observation with respect to testicular position. An ectopic gonad was diagnosed in 15% of the patients, most of whom had a patent processus vaginalis. Gubernacular attachment was in the scrotum in only a third of all cases studied. Undescended testes were softer and smaller than the contralateral gonad in the majority of cases. To our knowledge ours is the first study to correlate preoperative and intraoperative findings in cases of undescended testis. New anatomical as well as morphological and volumetric data are provided.

Histologic maldevelopment of unilaterally cryptorchid testes and their descended partners.

The pathogenesis of the increased incidence of subfertility in cryptorchidism remains controversial, and the concept that the prepubertal testis is a quiescent organ continues to be held by some. Histomorphometric analyses including total and differential germ cell counts and Leydig counts were performed on semithin sections of biopsies from 459 unilateral undescended testes and 356 of their contralateral descended partners in order to further investigate these two issues. The results demonstrate reduced numbers of Leydig cells, delayed disappearance of gonocytes, delayed appearance of adult dark spermatogonia, failure of primary spermatocytes to appear, and reduced total germ cell counts in the undescended testis. These findings support the hypothesis that understimulation of the testis leads to reduced numbers of Leydig cells which leads to delayed and defective maturation of germ cells and reduced total germ cell counts which underlie the increased risk of subfertility in cryptorchidism. The appearance of adult dark spermatogonia in the first year of life and the onset of meiosis at three years of life in the contralateral descended testes contradicts the view that the prepubertal testis is quiescent. Complete evaluation of prepubertal testicular biopsies should include total and differential germ cell counts and Leydig cell counts.

An absent testis is associated with contralateral testicular hypertrophy.

Surgical exploration was done in 109 boys ages birth through 9 years with unilateral impalpable testes by physical examination under anesthesia. Of the patients 51 (47%) had an absent testis and 58 had intra-abdominal testes. At open biopsy of the contralateral descended testis the 3 dimensions of the exposed testis were recorded and testicular volume was calculated. The mean volume of the contralateral descended testes of boys with an absent testis was greater than that of boys with intra-abdominal testes at all ages. The differences were significant (p = 0.0019 to 0.0117) from birth through year 4 but not from years 5 through 9. However, the standard deviations ranged from 27 to 74% of the means, and there was broad overlap of the volumes of the 2 groups. These findings indicate that, although the volume of the contralateral descended testis of boys with an absent testis is significantly greater than that of boys with intra-abdominal testes, the volume of the contralateral descended testis is not a reliable criterion for differentiating an absent testis from an intra-abdominal testis in a boy with a unilateral impalpable testis. Surgical exploration continues to be the method of choice for making the diagnosis of an absent testis.

Severe perinatal liver disease and Down syndrome: an apparent relationship.

Down syndrome (DS) is not usually thought of in association with significant infantile liver disease. We present clinical and histopathologic data from 10 patients with DS who presented with severe liver disease at birth or within the first few weeks of life, and summarize the findings of eight previously reported cases. The liver disease was fatal in all but one case. Diffuse lobular fibrosis surrounding proliferating ductular elements and residual hepatocytes characterized the pathologic findings in the liver in all patients. A large number of megakaryocytes were present in the liver in nine of 12 patients. The phenotype of "perinatal hemochromatosis" was documented in eight of nine cases in which the presence of iron was investigated. Since only a fraction of the patients with this phenotype have DS, the patients we describe seem to represent a relatively well-defined subset of the perinatal hemochromatosis phenotype. The existence of such a subset suggests that the perinatal hemochromatosis phenotype does not represent a single etiopathogenetic disorder. The association between DS, megakaryocytic infiltrates in the liver, and fatal subacute/chronic liver disease gives rise to the speculation that fibrosis-promoting factors and/or metabolic abnormalities, such as those resulting from a gene dosage effect, may play a role in the genesis of the liver disease, perhaps due to a particular susceptibility of fetal liver.

Early postnatal testicular maldevelopment in cryptorchidism.

It has been previously postulated that many cases of cryptorchidism are manifestations of a forme fruste of hypogonadotropic hypogonadism. In support of this theory the earliest postnatal histological abnormality in cryptorchid testes demonstrated by this morphometric study of semithin microscopic sections of testicular biopsies was hypoplasia of the Leydig cells, which was obvious from the first month of life. The second abnormality, defective transformation of gonocytes into adult dark spermatogonia, was significant from early in life. No reduction in the mean number of germ cells was detected in the first 7 months of life. The abnormal persistence of the untransformed gonocytes resulted in a total germ cell count that was similar to normal controls until the seventh month, when secondary degeneration of untransformed gonocytes led to a decrease in the total germ cell count. These findings are compatible with the hypothesis that the blunted neonatal surge of gonadotropins previously demonstrated in cryptorchid boys triggers a cascade of hormonal and secondary histological abnormalities that may culminate in a reduced fertility potential in adults. Early replacement hormonal therapy deserves further investigation as a rational approach to the treatment of germ cell maldevelopment and reduced fertility potential associated with cryptorchidism.

The morphometric histopathology of undescended testes and testes associated with incarcerated inguinal hernia: a comparative study.

The underlying injury to undescended testes may be hormonal, a transient perinatal form fruste of hypogonadotropic hypogonadism characterized by blunting of the surge in gonadotropins normally seen at age 60 to 90 days. Ischemia is the underlying injury to testes associated with incarcerated inguinal hernias. To determine if the histopathology of these 2 injuries is different histomorphometric analyses were performed on semithin microscopic sections of biopsies of 21 control testes, 17 undescended testes and 13 intrascrotal testes associated with incarcerated inguinal hernias. The infants in all groups were 30 to 120 days old. The results showed that, as in previous studies, undescended testes at this age are characterized by hypoplasia of Leydig cells, normal germ cell counts and defective maturation of gonocytes into adult dark spermatogonia. In contrast, testes associated with incarcerated inguinal hernias were characterized by hyperplasia of Leydig cells, reduced germ cell counts and normal maturation of gonocytes into adult dark spermatogonia. One might conclude that the underlying injury of undescended testes, presumably the blunted surge of gonadotropins, causes a primary hypoplasia and hypofunction of Leydig cells, which in turn causes a secondary defect in transformation of gonocytes into spermatogonia. In contrast, ischemia may primarily cause a tubular epithelial lesion leaving the hypothalamic-pituitary-gonadal axis intact and allowing normal transformation of gonocytes into spermatogonia. Reduced gonadotropins and ischemia appear to produce distinctly different primary and secondary pathophysiological effects on the testes.

Evidence in favor of the mechanical (intrauterine torsion) theory over the endocrinopathy (cryptorchidism) theory in the pathogenesis of testicular agenesis.

There are 2 competing theories regarding the pathogenesis of testicular agenesis--the endocrinopathy/cryptorchidism and the mechanical/intrauterine torsion theories. We compare the number of Leydig cells, total number of germ cells and the transformation of adult dark spermatogonia into primary spermatocytes in semithin sections of testicular biopsies from 59 contralateral descended testes of patients with testicular agenesis with those in the contralateral descended testes from 250 patients with unilateral cryptorchidism. The contralateral descended testes from boys with testicular agenesis demonstrated higher numbers of Leydig cells, higher numbers of total germ cells and a higher rate of transformation of adult dark spermatogonia into primary spermatocytes than did the contralateral descended testes from the patients with unilateral cryptorchidism. These findings favor the mechanical/intrauterine torsion theory over the endocrinopathy/cryptorchidism theory in the pathogenesis of testicular agenesis.