Undescended Testis Histology Correlation with Adult Hormone Levels and Semen Analysis

The fate of germ cells in cryptorchid testis

Cryptorchidism in males constitutes a notable risk factor for both infertility and testicular cancer. Infertility in adulthood is closely linked to the germ cell status in childhood. Furthermore, the significance of germ cell status is important as more than 95% of all reported testicular malignancies are germ cell tumors. The review aims to elucidate the pathogenesis of germ cells in cryptorchid testes concerning their association with infertility and testicular malignancies. Impaired germ cell numbers are evident in cryptorchid testes even during antenatal and neonatal stages. In cryptorchidism there is a rapid decline in germ cell number within the first year of life, partially attributed to physiologic gonocyte apoptosis. Additionally, germ cells fail to differentiate normally during mini-puberty leading to reduced germ cell proliferation and delayed clearance of gonocytes from the seminiferous epithelium. Absence of germ cells in testicular biopsies occurs already 10 months of age and germ cell deterioration progressively worsens with approximately 50% of persisting cryptorchid testes lacking germ cells during puberty. The deficient germ cell maturation and proliferation leads to later infertility. Elevated temperature in the cryptorchid testes and also hormonal deficiency contribute to this phenomenon. Germ cell neoplasia in situ (GCNIS) originating during fetal development may manifest in rare cases associated with disorders of sexual development, chromosomal abnormalities in boys, specific syndromes, and teratomas that include cryptorchidism. In adults, the presence of GCNIS predominantly represents a new histology pattern before invasive germ cell cancer is demonstrated and is neither congenital nor related to abnormal gonocyte transformation.

Management of the undescended testis in children: An American Pediatric Surgical Association Outcomes and Evidence Based Practice Committee Systematic Review

PURPOSE

Management of undescended testes (UDT) has evolved over the last decade. While urologic societies in the United States and Europe have established some guidelines for care, management by North American pediatric surgeons remains variable. The aim of this systematic review is to evaluate the published evidence regarding the treatment of (UDT) in children.

METHODS

A comprehensive search strategy and the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines were utilized to identify, review, and report salient articles. Five principal questions were asked regarding imaging standards, medical treatment, surgical technique, timing of operation, and outcomes. A literature search was performed from 2005 to 2020.

RESULTS

A total of 825 articles were identified in the initial search, and 260 were included in the final review.

CONCLUSIONS

Pre-operative imaging and hormonal therapy are generally not recommended except in specific circumstances. Testicular growth and potential for fertility improves when orchiopexy is performed before one year of age. For a palpable testis, a single incision approach is preferred over a two-incision orchiopexy. Laparoscopic orchiopexy is associated with a slightly lower testicular atrophy rate but a higher rate of long-term testicular retraction. One and two-stage Fowler-Stephens orchiopexy have similar rates of testicular atrophy and retraction. There is a higher relative risk of testicular cancer in UDT which may be lessened by pre-pubertal orchiopexy.

A narrative review of the history and evidence-base for the timing of orchidopexy for cryptorchidism

INTRODUCTION

Consensus recommendations for surgical management of cryptorchidism recommend orchidopexy between 6 and 18 months of age. The COVID-19 pandemic has impacted elective surgical scheduling.

OBJECTIVE

In response to the COVID-19 pandemic, we sought to review the available data regarding the natural history, surgical management, and infertility- and cancer-related risks associated with cryptorchid testes. The purpose of this review is to provide parents, referring providers, and surgeons with information to inform their decisions to proceed with or delay orchidopexy.

METHODS

A retrospective review and analysis of all available articles relevant to the natural history, surgical management, and infertility- and cancer-related risks of cryptorchidism present on PubMed, SCOPUS, and Cochrane Library was conducted.

RESULTS

The quality of historic literature pertaining to the effect of cryptorchidism on fertility and malignancy differ, with poorer data available on fertility. Cryptorchid testes may show histologic differences as early as birth, and some of these changes may have prognostic value in future fertility. Formerly unilateral cryptorchid men have slightly but not significantly reduced paternity rates compared to the general population. Cryptorchid testes have an increased risk of germ cell carcinogenesis, and robust data suggest the risk for malignancy in cryptorchid testes increases substantially after puberty.

CONCLUSION

The current body of evidence regarding the risks for future infertility and testicular cancer support the consensus recommendations for surgical correction of cryptorchidism between 6 and 18 months of age. During the uncertain time of the COVID-19 pandemic, decision for orchidopexy is a shared-decision between physician and parent. For an infant or young boy with a unilateral undescended testes, delaying orchidopexy several months until a time of decreased exposure risk is unlikely to result in substantial or sustained fertility or malignant risks.

Review of injection techniques for spermatogonial stem cell transplantation

BACKGROUND

Although the prognosis of childhood cancer survivors has increased dramatically during recent years, chemotherapy and radiation treatments for cancer and other conditions may lead to permanent infertility in prepubertal boys. Recent developments have shown that spermatogonial stem cell (SSC) transplantation may be a hope for restoring fertility in adult survivors of childhood cancers. For this reason, several centres around the world are collecting and cryopreserving testicular tissue or cells anticipating that, in the near future, some patients will return for SSC transplantation. This review summarizes the current knowledge and utility of SSC transplantation techniques.

OBJECTIVE AND RATIONALE

The aim of this narrative review is to provide an overview of the currently used experimental injection techniques for SSC transplantation in animal and human testes. This is crucial in understanding and determining the role of the different techniques necessary for successful transplantation.

SEARCH METHODS

A comprehensive review of peer-reviewed publications on this topic was performed using the PubMed and Google Scholar databases. The search was limited to English language work and studies between 1994 (from the first study on SSC transplantation) and April 2019. Key search terms included mouse, rat, boar, ram, dog, sheep, goat, cattle, monkey, human, cadaver, testes, SSC transplantation, injection and technique.

OUTCOMES

This review provides an extensive clinical overview of the current research in the field of human SSC transplantation. Rete testis injection with ultrasonography guidance currently seems the most promising injection technique thus far; however, the ability to draw clear conclusions is limited due to long ischemia time of cadaver testis, the relatively decreased volume of the testis, the diminishing size of seminiferous tubules, a lack of intratesticular pressure and leakage into the interstitium during the injection on human cadaver testis. Current evidence does not support improved outcomes from multiple infusions through the rete testes. Overall, further optimization is required to increase the efficiency and safety of the infusion method.

WIDER IMPLICATIONS

Identifying a favourable injection method for SSC transplantation will provide insight into the mechanisms of successful assisted human reproduction. Future research could focus on reducing leakage and establishing the optimal infusion cell concentrations and pressure.

Diagnosis and treatment of the intra-abdominal gonad in the pediatric population: Testes, ovaries, dysgenetic gonads, streaks, and ovotestes

BACKGROUND/PURPOSE

Pediatric surgical specialists are often confronted with the difficult task of identifying, diagnosing and managing intra-abdominal gonads in children. Ranging from the intra-abdominal cryptorchid testis to normal or pathologic ovaries and gonads in disorders of sexual development, all intra-abdominal gonads in the pediatric population pose different diagnosis and management challenges. Understanding the hormonal and fertility potential of the gonad and knowing its potential cancer risk is essential when deciding how to manage these patients. In addition, the ideal surgical management for each one of these patients is often debated.

METHODS

Descriptive literature review.

RESULTS/CONCLUSION

Herein, we reviewed gonadal formation, common etiologies, diagnosis and management of intra-abdominal testes, pathologic ovaries and gonads in disorders of sexual development. Fertility potential and cancer risk for each were also reviewed and how both affect surgical management of the gonad.

TYPE OF STUDY/LEVEL OF EVIDENCE

Review Article, Level V.

Management of cryptorchidism in adolescent and adult males

Background

In developing countries, it is not unusual for patients with undescended testes (UDT) to present in adulthood and the late detection of UDT can be problematic. The limited contribution to fertility and increased potential of malignancy seen in UDT have swayed many authors towards recommending orchidectomy, rather than orchidopexy, for the adult patient presenting with cryptorchidism. With conflicting data, and most guidelines aimed at first world countries with pre-pubertal patients as their focus group, a lot of uncertainty exists regarding the management of adults who present with cryptorchidism. This may result in variation in the approach to management of this patient population.

Methods

A retrospective review was conducted of patients with cryptorchidism, aged 12 years or older at the time of surgery. The following data were retrieved: patient’s age, medical and previous surgical history, clinical features of UDT (laterality, position and size), date of surgery, intra-operative findings and procedure performed. Management decisions were compared to the most recent guidelines.

Results

The mean age of the 106 subjects was 25.4 years. An orchidectomy was performed in a total of 30 (24.2%) of the 124 testicular units. The majority of testes, 91 (73.4%), in this group were preserved. Of these, 43 (47.3%) were older than 18 years of age, 33 (36.2%) were reported as having unilateral UDT with a normal contralateral testis and in 9 (9.8%) of these cases, the preserved testes were described as being atrophic. The majority (59.7%) of UDT in the post-pubertal group (> 18 years) were managed by orchidopexy.

Conclusion

Contrary to the recommended treatment for this group of patients, there was a general tendency towards testicular preservation. The decision on surgical management was made by the attending surgical team. This not only demonstrates variation in the management of UDT, but could also be a reflection of the lack of sufficient guidelines as to the management of the post-pubertal patient presenting with UDT. Further studies, following cryptorchidism through adulthood, are needed to refine guidelines for the optimal management of this group of patients.

Cryptorchidism, gonocyte development, and the risks of germ cell malignancy and infertility: A systematic review

BACKGROUND/AIM

Cryptorchidism, or undescended testis (UDT) occurs in 1%-4% of newborn males and leads to a risk of infertility and testicular malignancy. Recent research suggests that infertility and malignancy in UDT may be caused by abnormal development of the neonatal germ cells, or gonocytes, which normally transform into spermatogonial stem cells (SSC) or undergo apoptosis during minipuberty at 2-6 months in humans (2-6 days in mice). We aimed to identify the current knowledge on how UDT is linked to infertility and malignancy.

METHODS

Here we review the literature from 1995 to the present to assess the possible causes of infertility and malignancy in UDT, from both human studies and animal models.

RESULTS

Both the morphological steps and many of the genes involved in germ cell development are now characterized, but the factors involved in gonocyte transformation and apoptosis in both normal and cryptorchid testes are not fully identified. During minipuberty there is evidence for the hypothalamic-pituitary axis stimulating gonocyte transformation, but without known direct control by LH and androgen, although FSH may have a role. An arrested gonocyte maybe the origin of later malignancy at least in syndromic cryptorchid testes in humans, which is consistent with the recent finding that gonocytes are normally absent in a rodent model of congenital cryptorchidism, where malignancy has not been reported.

CONCLUSION

The results of this review strengthen the view that malignancy and infertility in men with previous UDT may be caused by abnormalities in germ cell development during minipuberty.

TYPE OF STUDY

Systematic review (secondary, filtered) LEVEL OF EVIDENCE: Level I.

Propagation of Spermatogonial Stem Cell-Like Cells From Infant Boys

Background

Gonadotoxic treatment of malignant diseases as well as some non-malignant conditions such as cryptorchidism in young boys may result in infertility and failure to father children later in life. As a fertility preserving strategy, several centers collect testicular biopsies to cryopreserve spermatogonial stem cells (SSCs) world-wide. One of the most promising therapeutic strategies is to transplant SSCs back into the seminiferous tubules to initiate endogenous spermatogenesis. However, to obtain sufficient numbers of SSC to warrant transplantation, in vitro propagation of cells is needed together with proper validation of their stem cell identity.

Materials and Methods

A minute amount of testicular biopsies (between 5 mg and 10 mg) were processed by mechanical and enzymatic digestion. SSCs were enriched by differential plating method in StemPro-34 medium supplemented with several growth factors. SSC-like cell clusters (SSCLCs) were passaged five times. SSCLCs were identified by immunohistochemical and immunofluorescence staining, using protein expression patterns in testis biopsies as reference. Quantitative polymerase chain reaction analysis of SSC markers LIN-28 homolog A (LIN28A), G antigen 1 (GAGE1), promyelocytic leukemia zinc finger protein (PLZF), integrin alpha 6 (ITGA6), ubiquitin carboxy-terminal hydrolase L1 (UCHL1) and integrin beta 1 (ITGB1) were also used to validate the SSC-like cell identity.

Results

Proliferation of SSCLCs was achieved. The presence of SSCs in SSCLCs was confirmed by positive immunostaining of LIN28, UCHL1 and quantitative polymerase chain reaction for LIN28A, UCHL1, PLZF, ITGA6, and ITGB1, respectively.

Conclusion

This study has demonstrated that SSCs from infant boys possess the capacity for in vitro proliferation and advance a fertility preservation strategy for pre-pubertal boys who may otherwise lose their fertility.

Hypogonadism and Cryptorchidism

Congenital cryptorchidism (undescended testis) is one of the most common congenital urogenital malformations in boys. Prevalence of cryptorchidism at birth among boys born with normal birth weight ranges from 1.8 to 8.4%. Cryptorchidism is associated with a risk of low semen quality and an increased risk of testicular germ cell tumors. Testicular hormones, androgens and insulin-like peptide 3 (INSL3), have an essential role in the process of testicular descent from intra-abdominal position into the scrotum in fetal life. This explains the increased prevalence of cryptorchidism among boys with diseases or syndromes associated with congenitally decreased secretion or action of androgens, such as patients with congenital hypogonadism and partial androgen insensitivity syndrome. There is evidence to support that cryptorchidism is associated with decreased testicular hormone production later in life. It has been shown that cryptorchidism impairs long-term Sertoli cell function, but may also affect Leydig cells. Germ cell loss taking place in the cryptorchid testis is proportional to the duration of the condition, and therefore early orchiopexy to bring the testis into the scrotum is the standard treatment. However, the evidence for benefits of early orchiopexy for testicular endocrine function is controversial. The hormonal treatments using human chorionic gonadotropin (hCG) or gonadotropin-releasing hormone (GnRH) to induce testicular descent have low success rates, and therefore they are not recommended by the current guidelines for management of cryptorchidism. However, more research is needed to assess the effects of hormonal treatments during infancy on future male reproductive health.

Advances in paediatric urology

Paediatric urological surgery is often required for managing congenital and acquired disorders of the genitourinary system. In this Series paper, we highlight advances in the surgical management of six paediatric urological disorders. The management of vesicoureteral reflux is evolving, with advocacy ranging from a less interventional assessment and antimicrobial prophylaxis to surgery including endoscopic injection of a bulking agent and minimally invasive ureteric reimplantation. Evidence supports early orchidopexy to improve fertility and reduce malignancy in boys with undescended testes. A variety of surgical techniques have been developed for hypospadias, with excellent outcomes for distal but not proximal hypospadias. Pelvi-ureteric junction obstruction is mostly detected prenatally; indications for surgery have been refined with evidence, and minimally invasive pyeloplasty is now standard. The outlook for patients with neurogenic bladder has been transformed by a combination of clean intermittent catheterisation, algorithms of diagnostic investigations, and innovative medical and surgical therapies. Posterior urethral valves are associated with considerable mortality; fetal diagnosis allows stratification of candidates for intervention, but ongoing bladder dysfunction in patients after valve ablation remains a cause of long-term morbidity.

Management of undescended testes: European Association of Urology/European Society for Paediatric Urology Guidelines

CONTEXT

Undescended testis is the most common endocrinological disease in the male newborn period. Incidence varies between 1.0% and 4.6% in full-term neonates, with rates as high as 45% in preterm neonates. Failure or delay of treatment can result in reduced fertility and/or increased testicular cancer risk in adulthood.

OBJECTIVE

To provide recommendations for the diagnosis and treatment of boys with undescended testes which reduce the risk of impaired fertility and testicular cancer in adulthood.

EVIDENCE ACQUISITION

Embase and Pubmed were searched for all relevant publications, from 1990 to 2015 limited to English language. Data were narratively synthesized in light of methodological and clinical heterogeneity. The risk of bias of each included study was assessed.

EVIDENCE SYNTHESIS

There is consensus that early treatment, by 18 months at the latest, for undescended testes is mandatory to avoid possible sequelae regarding fertility potential and cancer risk. The current standard therapy is orchidopexy, while hormonal therapy is still under debate. However, in some individuals the successful scrotal placement of previously undescended testes may not prevent potential negative long-term outcomes regarding fertility and testicular malignancy.

CONCLUSIONS

There is good evidence for early placement of undescended testes in the scrotal position to prevent potential impairment of fertility and reduce the risk of testicular malignancy. No consensus exists on the various forms of hormonal treatment, which are assessed on an individual basis.

What lessons can be learned from testicular histology in undescended testes?

Over the last 40-50 years studies involving thousands of testicular biopsies in boys with cryptorchidism have contributed to our knowledge of testicular histopathology and our understanding of the effects of cryptorchidism on the normal development of the germinal epithelium. Growth and maturation of germ cells and Leydig cells are crucial to allow boys to reach normal fertility potential. The following aberrations in testicular development are seen in cryptorchid testes: a decrease in total germ cell numbers, failure of fetal gonocytes (stem cells) to transform into adult dark (Ad) spermatogonia, failure for Ad spermatogonia to mature into primary spermatocytes, Leydig cell hypoplasia, and testicular fibrosis. All of these findings have been found to have a strong negative correlation with a boy’s age at the time of orchidopexy. Some of these findings have prognostic significance in regards to fertility potential especially when coupled with key clinical findings such as hormonal findings, age at orchidopexy, testicle size, laterality and location of cryptorchid testes. This review focuses on key lessons learned from testicular histology in cryptorchid testes.

Does early orchidopexy improve fertility?

Cryptorchidism or undescended testis (UDT) is a common problem in the pediatric male population. While spontaneous testicular descent occurs in the majority of cases, orchidopexy is the definitive treatment in those with remaining cryptorchid testis. A long established sequela to cryptorchidism is reduced fertility in the adult male and recent guidelines have advocated for earlier orchidopexy as studies have shown improvement in fertility rates when surgery is performed before one year of age. Further studies continue to validate these recommendations as recent research demonstrates crucial developmental steps even in very young boys. These steps are critical to complete testicular maturation and a loss of these milestones has increasingly been shown to decrease fertility later in life. This review examines the histological findings, hormonal data, and paternity rates from those who have undergone orchidopexy at varying ages and summarizes current recommendations aimed at preserving fertility as much as possible in this population.

Pre- and postoperative status of gonadotropins (FSH and LH) and inhibin-B in relation to testicular histopathology at orchiopexy in infant boys with unilateral undescended testes

PURPOSE

In recent publications of boys with cryptorchidism, gonadotropins are higher and serum inhibin-B lower than normal. To some extent, serum values of inhibin-B reflect the state of germinative epithelium in cryptorchid testes. The aim of the present study was to evaluate the impact of unilateral orchiopexy on levels of gonadotropins and inhibin-B and correlate the hormone findings to the histopathology of the unilateral undescended testis.

METHODS

50 boys (mean age: 1 year and 2 months) operated for unilateral cryptorchidism had blood samples for serum luteinizing hormone (LH), follicle-stimulating hormone (FSH) and inhibin-B taken preoperatively and 3 months to 2 years postoperatively. Testicular biopsies were performed at orchiopexy. The total germ cell number per transverse tubule and presence of adult dark spermatogonia were estimated.

RESULTS

Preoperatively, 8 patients had impaired inhibin-B levels. In contrast with the expected normal physiological decline, 16 patients had an absolute rise in serum inhibin-B level postoperatively. The 4 patients who normalized the preoperative impaired serum level of inhibin-B all had low germ cell number in the testis at time of operation. Nine patients had preoperatively elevated serum levels of both LH 0.5-2.3 IU/l (mean: 1.0 IU/l) and FSH 1.3-2.2 IU/l (mean: 1.6 IU/l). Eight of these patients normalized both LH and FSH serum values postoperatively. None of the 4 boys with impaired inhibin-B level that did not normalize after surgery had elevated gonadotropins.

CONCLUSION

Orchiopexy in unilateral cryptorchidism had a clear impact on the serum level of inhibin-B and gonadotropins of 32% and 16%, respectively.

Undescended testis and infertility-Is hormonal therapy indicated?

PURPOSE

The purpose of this chapter is to review hormonal therapy in cryptorchidism in boys to improve fertility.

METHODS

Multiple searches, primarily in PubMed, were performed using various combinations of the terms: cryptorchidism, undescended testis (UDT), hormonal therapy, fertility, infertility, germ cell numbers, spermatogonia and semen analyses. In additions the pertinent articles from the reference lists in these papers were also obtained and reviewed.

RESULTS

Data on fertility in unilateral cryptorchidism does not reveal a significant risk for infertility. Testes biopsies in childhood do not correlate with fertility parameters in adulthood. In bilateral cryptorchidism there is a significant risk of infertility. Results of hormonal treatment were not reported separately for bilateral cryptorchidism. Current data is insufficient to know if hormonal therapy is efficacious in bilateral UDT.

CONCLUSIONS

Hormonal therapy should not be used in childhood to improve fertility in cases of unilateral cryptorchidism. Testes biopsies in childhood to identify those at risk for infertility should not be performed in unilateral cryptorchidism. More data are needed to answer whether hormonal therapy is beneficial in bilateral UDT. There is insufficient data to establish that testis biopsies are helpful in bilateral cryptorchidism in identifying the subgroup with risk for infertility. They should not be performed in the routine clinical setting but may have a role in a research protocol.

A diagnostic model for histologic damage in undescended testes based on testis rigidity measurement: an experimental study with a novel device

BACKGROUND

We aimed to test whether testis rigidity (hardness) measured using a newly-designed device we previously introduced would offer more reliable assessment of histologic damage in undescended testes than conventional methods (consistency feel at palpation, volume measurement).

MATERIALS AND METHODS

Forty-five 18-d-old Lewis rats underwent surgical inhibition of descent of left testes and were followed to 40 (n = 16), 63 (n = 14), or 90 days (n = 15). Another 45 18-d-old Lewis rats were sham operated (left side) and followed likewise (n = 14, n = 15, and n = 16). At the designated time points, testes were exposed bilaterally, rigidity was measured, and consistency at palpation was scored; testes were removed and subjected to length, width, weight measurements, volume calculation, and histomorphometry (mean Johnsen score [MJS], mean tubular diameter [MTD], and mean capsule width [MCW]). Testes of experimental group were compared with ipsilateral testes of sham-operated rats.

RESULTS

At all time points, undescended testes had decreased rigidity, MJS, and MTD, increased MCW, decreased volume and weight; contralateral testes remained unaffected. Rigidity was associated only with MJS and MTD, and most strongly with MJS (multiple stepwise linear regression, F = 694.44, P < 0.0005). MJS could be precisely predicted from rigidity: MJS = 0.699 × testis rigidity (F = 1358.82, P < 0.0005). This model showed good fit between predicted and actual MJS values (R(2) = 0.94), low error, nonsignificant bias, sensitivity 75% and specificity 90%. Model validation showed low prediction error and nonsignificant bias, indicating generalizability. Testis volume and palpation proved imprecise MJS predictors.

CONCLUSIONS

Testis rigidity is an effective predictor of histologic damage in rat undescended testes, with diagnostic value superior to testis palpation scoring and volume measurement.