Postnatal germ cell development during first 18 months of life in testes from boys with non-syndromic cryptorchidism and complete or partial androgen insensitivity syndrome

INTRODUCTION

Neonatal testicular germ cells/gonocytes, transform into stem cells for spermatogenesis during 'minipuberty', driving change in timing of surgery. This study examined gonocyte transformation in cryptorchid testes in children ≤18 months of age with unilateral, bilateral undescended testes (UDT), complete or partial androgen insensitivity syndrome (CAIS, PAIS) [3,4].

MATERIAL AND METHODS

Testicular biopsies were taken from patients with unilateral or bilateral UDT, PAIS or CAIS, aged 10 days-18 months. These testicular sections underwent immunohistochemistry with antibodies (Oct4, Ki67, C-Kit, Sox9) followed by confocal imaging, cell counting and statistical analysis.

RESULTS

Both Sertoli cells/tubule and germ cells (GC)/tubule decreased with age, and % empty tubules (no GC) increased with age but with no significant differences between patient groups. Oct4⁺ germ cells/tubule decreased with age. There are some GCs and Sertoli cells proliferating during the first year and most proliferating Oct4⁺ germ cells (Oct4⁺/Ki67⁺) were located off tubular basement membrane.

CONCLUSION

Our study showed that Oct4 expression gradually decreased after minipuberty and transformation into spermatogonia. Germ cells and Sertoli cells undergo mitosis during the first 12 months although not abundantly. We propose that Oct4⁺ gonocyte transformation into spermatogonia via proliferation and migration to the basement membrane may be delayed in UDT.

Frequency of inguinal herniotomy in Australia (1998-2017)

BACKGROUND/AIM

Closure of the processus vaginalis (PV) is considered as the last step of testicular descent. Therefore, patent processus vaginalis (PV), and inguinal hernias are linked to cryptorchidism. As the National Australian incidence of orchidopexy has decreased over the previous 20 years, we aimed to explore the incidence of inguinal herniotomy (including hydrocele) over time in Australia.

METHODS

The National Department of Human Services (DHS) database, and Bureau of Statistics database were obtained for the years 1998-2017. The numbers of inguinal herniotomies in patients aged 0-4, 5-14 and 15-24 yearswere examined with ethical approval.

RESULTS

Over the 20-year period, over 87,000 inguinal herniotomy procedures were performed in males. The incidence per year in males decreased across all ages over the 20-year period, but was most pronounced in infants and toddlers. Similar to males, the incidence in females decreased over time, with the ratio of procedures per head of population decreasing in children under 5 years of age. The ratio of male: females varied according to ages, and was between 2.8 and 6.2 males: 1 female.

CONCLUSION

This study suggests that fewer 0-4-year olds are undergoing inguinal herniotomy, compared with 20 years ago. This is likely due to a change in practice for the management of unilateral symptomatic hernias, from routine bilateral herniotomies, to unilateral surgery. As well as less aggressive surgical intervention for hydroceles in boys.

LEVEL OF EVIDENCE

III.

Postnatal Germ Cell Development in the Cryptorchid Testis: The Key to Explain Why Early Surgery Decreases the Risk of Malignancy

PURPOSE

 Cryptorchidism is a risk factor for testicular malignancy and surgical treatment lowers this risk. This study aimed to investigate the germ cell behavior in prepubertal cryptorchid testes using immunohistochemical markers for germ cell malignancy to understand how early orchiopexy may possibly prevent cancer developing.

MATERIALS AND METHODS

 Histology sections from 1,521 consecutive testicular biopsies from 1,134 boys aged 1 month to 16.5 years operated for cryptorchidism were incubated with antibodies including antiplacental-like alkaline phosphatase (PLAP), anti-Oct3/4, anti-C-kit, and anti-D2-40.

RESULTS

 Oct3/4 and D2-40-positive germ cells are found throughout the first 2 years of life, with declining frequency thereafter. After 2 years, they should have disappeared and may indicate neoplasia. PLAP-positive cells were seen in 57 to 82% and C-kit-positive cells in 5 to 21% of cryptorchid testes between 4 and 13 years. Not until puberty did PLAP and C-kit-positive undifferentiated spermatogonial stem cells vanish. Only 0.3% of the present material had obvious prepubertal intratubular germ cell neoplasia (ITGCN) and they all had syndromic cryptorchidism. An additional three boys (0.3%) older than 2 years had weak Oct3/4 expression in undescended testes, but all cases were D2-40 negative.

CONCLUSION

 Prepubertal ITGCN was rare and mostly seen in syndromic cryptorchidism. In nonsyndromic cryptorchidism PLAP-positive undifferentiated spermatogonial stem cells persisted in a significant proportion of nontreated undescended testes and they will be especially sensitive to long-lasting abnormally high temperature that may be the single most important cause facilitating the accumulation of mutations during cell replication and the development of ITGCN to be prevented by orchiopexy.

The long-term quality of life outcomes in adolescents with Hirschsprung disease

BACKGROUND

Postoperative outcomes for Hirschsprung disease (HD) remain variable, with many patients affected by constipation and/or fecal incontinence. The long-term impact upon quality of life (QoL) for HD patients is unclear. We measured long-term QoL outcomes in adolescents with HD using validated questionnaires.

METHODS

Patients with HD, managed at a large tertiary pediatric institution between 1997 and 2004, were identified. Patients and/or their proxy completed validated questionnaires. Results were compared with published healthy population controls. Two questionnaires assessed QoL: Pediatric Quality of Life Inventory (PedsQL) and Fecal Incontinence and Constipation Quality of Life (FICQOL). Three measures assessed functional outcomes: Baylor Continence Scale, Cleveland Clinic Constipation Scoring System, and Vancouver Dysfunctional Elimination Symptom Survey.

RESULTS

Interviews were completed for 58 (70% response rate) patients [M:F, 49:9; median age, 14.5 years (11.1-18.7)]. No significant differences were found in general QoL scores between patients and healthy controls (84.84 versus 81.49, p = 0.28). Disease-specific questionnaires revealed reduced QoL in patients and families, with 17% of parents reporting the bowel dysfunction stopped their child from socializing and 47% of parents experiencing some degree of anxiety/depression regarding their child's bowel condition. Fecal incontinence (r = -0.59, p < 0.01), constipation (r = -0.36, p = 0.01), and dysfunctional elimination (r = -0.59, p < 0.01) all negatively correlated with QoL scores.

CONCLUSIONS

In this study, generic QoL in the adolescent HD population was comparable to healthy populations. However, children with HD have ongoing bowel dysfunction which negatively impacts upon their QoL.

LEVEL OF EVIDENCE

Prognosis study:- level II (prospective cohort study).

The burden of surgery and postoperative complications in children with inflammatory bowel disease

BACKGROUND

Pediatric inflammatory bowel disease (IBD) may be associated with a higher burden of surgery and postoperative complications. This study aimed to measure the burden in pediatric IBD over a 20-year period in a large tertiary referral center.

METHODS

A retrospective review was conducted of children diagnosed with IBD between 1996 and 2015, with a focus upon operative intervention (excluding endoscopy) and postoperative outcomes.

RESULTS

Of 786 IBD patients, 121/581 (20.8%) with Crohn's disease (CD) and 22/205 (10.7%) with ulcerative colitis (UC) underwent surgery during the study period. When comparing 10-year epochs for CD, median time from diagnosis to intervention decreased from 34 months to 3 months (P < 0.0001). Postoperative complications occurred in 16/121 (13%) CD patients (bowel obstruction: 10, anastomotic stricture: 4, stomal issues: 4, anastomotic leak: 1). Within the UC cohort, the median time from diagnosis to intervention decreased from 62 months to 6 months (P = 0.0019). Postoperative complications occurred in 9/22 (41%) UC patients (bowel obstruction: 7, stomal issues: 3, anastomotic stricture: 1). Compared with CD, complications were more frequent in UC patients (P = 0.004).

CONCLUSION

Surgery and postoperative complications are common in pediatric IBD. The timing of intervention has trended towards earlier operations in both CD and UC.

LEVEL OF EVIDENCE

Treatment study-level III (retrospective comparative study).

Treatment of fecal impaction in children using combined polyethylene glycol and sodium picosulphate

Background and Aim

Polyethylene glycol (PEG) is the gold standard for fecal disimpaction in constipation. A regimen of PEG combined with the stimulant laxative sodium picosulphate (SPS) produced fecal disimpaction in chronically constipated children in the community, but it is unknown if it is effective for more severe constipation. To determine the stool output and effect of a combined PEG and SPS regimen on fecaloma in children with severe constipation and impaction.

Methods

Children with symptoms for a duration of ≥2 years, a palpable fecaloma, and enlarged rectum on X-ray (rectal: pelvic ratio > 0.6) were recruited from a tertiary hospital. Daily diaries recorded laxative dose, stool frequency, volume, and consistency (Bristol stool scale, BSS). Abdominal X-rays were taken on day 1 and day 8, and stool loading was assessed using the Leech score. Laxative doses were based on the child's age. The dose of PEG with electrolytes taken was 2-8 sachets (14.7 g/sachet) on days 1-2, reducing to 2-6 sachets on day 3. The SPS dose was 15-20 drops on days 2-3.

Results

Eighty-nine children (4-18 years) produced a large volume of soft stool (median/inter-quartile-range: 2.2/1.6-3.1 L) over 7 days. Stool volume on X-rays decreased significantly in the colon (P < 0.001). Fecalomas resolved in 40 of 89 children, while 49 needed a second high dose. Rectal:pelvic ratios did not change.

Conclusions

A combined high dose of PEG and SPS on days 1 and 2 was effective in removing the fecaloma in half of the children. Administering high doses for a longer period should be tested to provide outpatient disimpaction for severe fecalomas. Rectums remained flaccid after emptying.

FGF10 and the Mystery of Duodenal Atresia in Humans

Background: Duodenal atresia (DA) is a congenital obstruction of the duodenum, which affects 1 in 7000 pregnancies and requires major surgery in the 1st days of life. Three morphological DA types are described. In humans, the association between DA and Down syndrome suggests an underlying, albeit elusive, genetic etiology. In mice, interruption of fibroblast growth factor 10 (Fgf10) gene signaling results in DA in 30–50% of embryos, supporting a genetic etiology. This study aims to validate the spectrum of DA in two novel strains of Fgf10 knock-out mice, in preparation for future and translational research.

Methods: Two novel CRISPR Fgf10 knock-out mouse strains were derived and embryos generated by heterozygous plug-mating. E15.5–E19.5 embryos were genotyped with respect to Fgf10 and micro-dissected to determine the presence and type of DA.

Results: One twenty seven embryos (32 wild-type, 34 heterozygous, 61 null) were analyzed. No wild-type or heterozygous embryos had DA. However, 74% of Fgf10 null embryos had DA (49% type 1, 18% type 2, and 33% type 3).

Conclusion: Our CRISPR-derived strains showed higher penetrance of DA due to single-gene deletion of Fgf10 in mice than previously reported. Further, the DA type distribution in these mice more closely reiterated that observed in humans. Future experiments will document RNA and protein expression of FGF10 and its key downstream signaling targets in normal and atretic duodenum. This includes exploitation of modern, high-fidelity developmental tools, e.g., Fgf10^flox/+–tomato^flox/flox mice.

Dietary exclusion of fructose and lactose after positive breath tests improved rapid-transit constipation in children

Aims

Exclusion of fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAPs) from the diet is effective in alleviating symptoms of irritable bowel syndrome (IBS) in adults. Rapid‐transit constipation (RTC) is a recently discovered subset of chronic constipation and has been linked to food intolerance. The aim of this study was to audit the effect of specific FODMAP elimination diets in children with RTC.

Methods

This was an audit of children presenting to a tertiary children's hospital surgeon with refractory chronic constipation who had rapid transit in the proximal colon on nuclear imaging; had hydrogen/methane breath tests for fructose, lactose, and/or sorbitol intolerance; and were advised to exclude positive sugar under clinical supervision. Patients filled in a questionnaire rating severity of constipation, abdominal pain, and pain on defecation with a visual analogue scale (VAS, 0 = none, 10 = high) and stool consistency for 6 months before and after dietary exclusion.

Results

In responses from 29 children (5–15 years, 21 males), 70% eliminated fructose, and 40% eliminated lactose. There was a significant reduction in the severity of constipation (VAS mean ± SEM, pre 5.8 ± 0.5 vs post 3.3 ± 0.6, P < 0.0001), abdominal pain (5.1 ± 0.6 vs 2.8 ± 0.5, P = 0.0004), pain on defecation (5.8 ± 0.6 vs 2.6 ± 0.5, P < 0.0001), and increase in stool wetness (Bristol Stool Scale pre 3.3 ± 0.3 vs post 3.9 ± 0.2, P = 0.004).

Conclusion

Children with RTC showed significant improvements in constipation and pain after excluding the sugar indicated by positive breath tests, suggesting that specific sugar‐exclusion diets may have a role in the management of RTC in children.

Long-term urinary symptoms in adolescent and adult women with congenital adrenal hyperplasia

BACKGROUND

Congenital adrenal hyperplasia (CAH) is an autosomal recessive condition resulting in excess androgen production. Females are typically born with ambiguous genitalia and often undergo feminising genitoplasty in infancy or childhood. Recently, there has been considerable international debate as to whether distressing urinary symptoms in CAH patients are truly present and, if so, whether these urinary problems are a consequence of the feminising genitoplasty.

OBJECTIVE

To identify and assess any urinary symptoms in an Australian cohort of adolescent and adult women with CAH who have undergone feminising genitoplasty in infancy, childhood or adolescence as a part of their management.

STUDY DESIGN

Females with CAH aged 12-40 years, who had undergone feminising genitoplasty, and were identified from a hospital database (n = 72). Those aged 12-15 years were assessed using the Paediatric Incontinence Symptom Index questionnaire in conjunction with sections of the Bristol Female Lower Urinary Tract Symptoms Scored Form questionnaire. Those aged 16-40 years were assessed using the Bristol Female Lower Urinary Tract Symptoms Scored Form questionnaire. Uroflowmetry studies and post-void residual volume ultrasounds were also conducted. Previously published normative data were used for the control population.

RESULTS

Responses to the questionnaire indicated that CAH patients had a higher incidence of urgency, frequency, urge incontinence, unexplained incontinence and nocturnal incontinence, when compared to previously published control data. Average and maximum urine flow rates measured by uroflowmetry were within normal range; however, the 16-40-year-old age group had significantly increased mean post-void residual volumes (P < 0.001) (Summary table).

DISCUSSION

The presence of lower urinary tract symptoms in these patients has previously been interpreted as a direct outcome of feminising genitoplasty; however, these results could also be accounted for by the virilisation of pelvic floor musculature. Androgens have been shown to increase skeletal muscle mass, but their exact impact on the pelvic floor musculature requires further research. Three previous studies have measured post-void residual volumes in patients with CAH, all of which found it them be raised.

CONCLUSIONS

Patients with CAH appeared to have overall normal urinary flow but increased post-void residual volumes. The data suggested that this population of patients has an increased probability of incontinence, urgency, and frequency when compared to a control population. These results confirmed findings of other small studies; however, it remains unclear if these changes reflected the underlying diagnosis or were a consequence of management.

Horse-related injuries in children - unmounted injuries are more severe: A retrospective review

INTRODUCTION

Horse-related injuries account for one quarter of all paediatric sports fatalities. It is not known whether the pattern of injury spectrum and severity differ between children injured whilst mounted, compared with those injured unmounted around horses. We aimed to identify any distinctions between the demographic features, spectrum and severity of injuries for mounted versus unmounted patients.

PATIENTS AND METHODS

Trauma registry data were reviewed for 505 consecutive paediatric patients (aged<16years) admitted to a large paediatric trauma centre with horse-related injuries over a 16-year period. Patients were classified into mounted and unmounted groups, and demographics, injury spectrum, injury severity, and helmet usage compared using odds ratios and Wilcoxon rank-sum tests.

RESULTS

More patients (56%) were injured in a private setting than in a sporting or supervised context (23%). Overall, head injuries were the most common horse-related injury. Mounted patients comprised 77% of the cohort. Mounted patients were more likely to sustain upper limb fractures or spinal injuries, and more likely to wear helmets. Unmounted were more likely to be younger males, and more likely to sustain facial or abdominal injuries. Strikingly, unmounted children had significantly more severe and critical Injury Severity Scores (OR 2.6; 95% CI 1.5, 4.6) and longer hospital stay (2.0days vs 1.1days; p<0.001). Unmounted patients were twice as likely to require intensive care or surgery, and eight times more likely to sustain a severe head injury.

CONCLUSIONS

Horse-related injuries in children are serious. Unmounted patients are distinct from mounted patients in terms of gender, age, likelihood of personal protective equipment use, severity of injuries, and requirement for intensive or invasive care. This study highlights the importance of vigilance and other safety behaviours when unmounted and around horses, and proposes specific targets for future injury prevention campaigns, both in setting of organised and private equestrian activity.

Presence of viable germ cells in testicular regression syndrome remnants: Is routine excision indicated? A systematic review

There is no consensus in the literature about the necessity for excision of testicular remnants in the context of surgery for an impalpable testis and testicular regression syndrome (TRS). The incidence of germ cells (GCs) within these nubbins varies between 0 and 16% in previously published series. There is a hypothetical potential future malignancy risk, although there has been only one previously described isolated report of intratubular germ-cell neoplasia. Our aim was to ascertain an accurate incidence of GCs and seminiferous tubules (SNTs) within excised nubbins and hence guide evidence-based practice. The systematic review protocol was designed according to the PRISMA guidelines, and subsequently published by the PROSPERO database after review (CRD42013006034). The primary outcome measure was the incidence of GCs and the secondary outcome was the incidence of SNTs. The comprehensive systematic review included articles published between 1980 and 2016 in all the relevant databases using specific search parameters and terms. Strict inclusion and exclusion criteria were ultilised to identify articles relevant to the review questions. Twenty-nine paediatric studies with a total of 1455 specimens were included in the systematic review. The mean age of the patients undergoing nubbin resection was 33 months and the TRS specimen was more commonly excised from the left (68%). The incidence of SNTs was 10.7% (156/1455) and the incidence of GCs, 5.3% (77/1455). Histological analysis excluding the presence of either SNTs or GCs was consistent with TRS, fibrosis, calcification or haemosiderin deposits. There is limited evidence on subset analysis that GCs and SNTs may persist with increasing patient age. This systematic review has identified that 1 in 20 of resected testicular remnants has viable GCs and 1 in 10 has SNTs present. There is insufficiently strong evidence for the persistence of GCs and SNTs with time or future malignant potential. Intra-abdominal TRS specimens may contain more elements and, therefore, require excision, although this is based on limited evidence. However, there is no available strong evidence to determine that a TRS specimen requires routine excision in an inguinal or scrotal position.

The spectrum of pediatric injuries sustained in snow sports

BACKGROUND

Snow sports are popular among children but carry the potential for significant injury. Head injuries are less common than fractures and sprains but may be fatal. Helmets are recommended for all snow sports, and yet their effectiveness remains unknown. We aimed to evaluate the spectrum of injuries sustained at three large alpine resorts and to assess the effect of helmet usage on injury severity.

METHODS

We performed a retrospective analysis of prospectively collected pediatric trauma data (2005-2015) from the three largest alpine resorts in our state. Data were analyzed using Spearman's correlation, chi-square, and odds ratio.

RESULTS

A total of 6299 incidents were reviewed. Skiers accounted for 3821 (60.7%) patients, while snowboarders accounted for 2422 (38.5%) patients. More than half (53.5%) of the injuries were related to falls, predominantly affecting knees in skiers and wrists in snowboarders. Overall, helmet usage decreased with age (p<0.001), though helmet uptake was positively associated with higher level of ability in both skiers and snowboarders (p<0.001). Concussions in both skiers and snowboarders were inversely correlated with the rates of helmet usage (p<0.05).

CONCLUSION

Helmet usage was associated with reduced rates of concussion. However, helmet usage decreased with age. We advocate for promotion of helmet usage, using mandatory guidelines, across all pediatric age groups.

LEVEL OF EVIDENCE

Level II - Retrospective study.

Frequency of revision orchidopexy in Australia 1995-2014

BACKGROUND/AIM

International criteria currently suggest orchidopexy at 6-12months for congenital undescended testis (UDT). Some children require repeat orchidopexy for recurrent UDT. This study aimed to assess practice in Australia over a 20-year period.

METHODS

We examined 20years of Australian orchidopexy data (1995-2014) from the Department of Human Services to explore the national revision orchidopexy rates over time.

RESULTS

The total number of orchidopexy revisions was 890 over 20years compared with 25,984 primary operations. More than 50% of all primary and revision orchidopexies in 0-14year-old boys were performed in major population centers of NSW and Victoria (which hold 52% male population of same age), with a small number of revisions on 15-24year-old males. The incidence of revision orchidopexy significantly decreased over the 20-year period in boys ages 0-14years old, from 276 operations between 1995 and 1999 decreasing to 165 operations between 2010 and 2014 (-53%), compared to a population increase of +15% (p<0.05).

CONCLUSION

These data demonstrate a decrease in revision orchidopexy since 1995, which may be related to change in referral practice with more children undergoing orchidopexy (primary and revision) by pediatric surgeons over the 20-year period.

LEVEL OF EVIDENCE

Level IV.

TYPE OF STUDY

Therapeutic Case Series with no Comparison Group.

Is selective echocardiography in duodenal atresia the future standard of care?

BACKGROUND

Duodenal atresia (DA) is associated with cardiac defects that may have perioperative care implications. Standard preoperative care includes echocardiography to identify such cardiac defects, but this dogma has been challenged. We aimed to assess selective and selective strategies for preoperative echocardiography in DA patients.

METHODS

Single-center retrospective review of neonates with DA over a 16-year period was performed. Data included preoperative cardiovascular and respiratory examination, chest x-ray, and echocardiography. We compared the current nonselective versus selective strategies, limiting preoperative echocardiogram to those in whom: (1) cardiac or respiratory or chest x-ray examination was abnormal, or (2) cardiac or respiratory examination was abnormal. Sensitivity, specificity, positive and negative predictive values were compared with chi-square tests.

RESULTS

Seventy-one of 109 (65%) consecutive neonates with DA underwent preoperative echocardiography according to a nonselective, physician-determined strategy. Forty of 71 (56%) patients had cardiac defects, including 16/40 (27%) major defects. Sixteen additional postoperative echocardiograms revealed 2 missed major defects. In the same cohort, selective strategies would have performed 17-24% fewer echocardiograms without significant detriment in performance.

CONCLUSIONS

All strategies considered missed some major cardiac defects. A selective strategy, determining DA patients not requiring preoperative echocardiogram, could reduce the number of echocardiograms performed without compromising patient safety.

TYPE OF STUDY

Retrospective study.

LEVEL OF EVIDENCE

Level II.

Testicular ectopia: Why does it happen and what do we do?

BACKGROUND/AIM

Testicular ectopia is rare, but the large range of anatomical locations described in the literature has spawned an abundance of possible theories to explain etiology. However, as the anatomical characteristics of normal testicular descent have only been elucidated recently, many of the theories of testicular ectopia do not incorporate this new perspective. In this study we aimed to determine what was in the literature about ectopic testis since 1980, and then try to explain the different anatomical variants in the light of current knowledge about testicular descent.

METHODS

A literature search was performed and all articles in English published since 1980 about testicular ectopia using several key words were identified.

RESULTS

A total of 271 articles in English were found, of which 31 addressed the pathophysiology and are the primary focus of this study. Case reports and reviews described perineal ectopia (×4), transverse testicular ectopia (×11), and abdominal ectopia (×2), along with 3 reviews/case reports addressing diagnosis and management. A range of proposed causes were found, including obstructed 'third inguinal ring' at neck of scrotum, abnormal CGRP function, aberrant distal gubernacular attachment, mechanical hindrance from retained Müllerian ducts, defective gubernacular formation or disruption of the gubernacular attachment to the testis.

CONCLUSION

After reviewing the proposed theories, we propose a unifying theory, based on current knowledge of testicular descent, where testicular ectopia can be explained by a) anomalous attachment of the gubernaculum to the anterior abdominal wall during transabdominal descent, or b) aberrant migration of the gubernaculum during the inguinoscrotal phase of testicular descent.

Undescended testis: What paediatricians need to know

Undescended testis (UDT) occurs when something goes wrong with testicular descent from high in the abdominal cavity to the scrotum. Normal descent occurs in two steps, with the transabdominal phase controlled by a new testicular hormone, insulin-like hormone 3, and the inguinoscrotal phase controlled by androgens. The latter phase requires a complex process of migration from the inguinal abdominal wall to the scrotum and is commonly defective, leading to the high incidence (2-4%) of UDT at birth. The clinical examination of babies and infants aims to confirm the persistence of congenital UDT by 3-6 months, so surgery can be optimally timed at 6-12 months. For those boys who develop acquired UDT later in childhood, the 'ascending' testis often needs surgery between 5 years and 10 years, so all boys should be screened again for UDT at school entry.

The possible role of AMH in shortening the gubernacular cord in testicular descent: A reappraisal of the evidence

BACKGROUND/AIM

Anti-Müllerian hormone (AMH), also called Müllerian inhibiting substance (MIS), is glycoprotein hormone secreted by the fetal Sertoli cells to regulate regression of the Müllerian ducts, the anlagen of the uterus, fallopian tubes, and upper vagina. After its existence was predicted in 1946 and its isolation and purification in the 1970's, a huge amount of information has been gathered on its molecular biology and function in the last 30-40years. Once thought to be a locally acting factor in the male fetus during sexual differentiation, it is now recognized as an endocrine hormone present in both sexes and with functions throughout life. One of the remaining controversies is the possible role of AMH during fetal testicular descent. In the human with aberrant AMH function, the boy has cryptorchidism with persistent Müllerian duct syndrome (PMDS), where the testes are often intraabdominal and on an abnormally long gubernacular cord. By contrast, in rodent models knockout of the AMH gene does not cause cryptorchidism.

METHODS/RESULTS

In this review we examined the evidence in the literature for and against a role for AMH in testicular descent and considered the implications of the different anatomy of the gubernacular cord in rodents versus children.

CONCLUSION

We conclude that AMH may have a role in shortening the gubernacular cord in humans which is concealed in rodent models by differences in anatomy of the gubernacular cord in rodents. The controversy could be resolved by re-examination of the gubernacular cord in boys with PMDS and mice with AMHKO.

TYPE OF STUDY

Review.

LEVEL OF EVIDENCE

V.

Multiple endocrine neoplasia 2B: Differential increase in enteric nerve subgroups in muscle and mucosa

Multiple endocrine neoplasia 2B (MEN2B) is a rare syndrome caused by an activating mutation of the RET gene, leading to enteric gangliomatosis. This child presented with constipation at 1-mo old, was diagnosed with MEN2B by rectal biopsy at 4 mo, had thyroidectomy at 9 mo and a colectomy at 4 years. We studied the extent of neuronal and nerve fibre proliferation and which classes of enteric nerves are affected by examining the colon with multiple neuronal antibodies. Resected transverse colon was fixed, frozen, sectioned and processed for fluorescence immunohistochemistry labelling with antibodies against TUJ1, Hu, ChAT, NOS, VIP, SP and CGRP and cKit. Control transverse colon was from the normal margin of Hirschsprung (HSCR) colon (4-year-old) and a child with familial adenomatous polyposis (FAP, 12 year). Myenteric ganglia were increased in size to as wide as the circular muscle. There was a large increase in nerve cells and nerve fibres. ChAT-, NOS-, VIP- and SP-immunoreactive nerve fibres all increased in the myenteric ganglia. NOS-IR nerves preferentially increased in the muscle, while VIP and SP increased in submucosal ganglia and mucosal nerve fibres. The density of ICC was normal. RET overactivation in MEN2B lead to a large increase in intrinsic nerve fibres in the myenteric and submucosal ganglia, with a relative increase in NOS-IR nerve fibres in the circular muscle and VIP and SP in the submucosal ganglia and mucosa. The changes were associated with severe constipation resulting in colectomy at 4 years.

The undescended testis: Clinical management and scientific advances

Undescended testes (UDT), where one or both testes fail to migrate to the base of the scrotum, can be congenital (2-5% of newborn males) or acquired (1-2% of males). The testis may be found in any position along its usual line of descent. Cryptorchidism affects the developing testicular germ cells and increases the risk of infertility and malignancy. Clinical management aims to preserve spermatogenesis and prevent the increased risk of seminoma. Examination to document the testicular position will guide the need for imaging, medical management and the surgical approach to orchidopexy.