Caucasian male infants and boys with hypospadias exhibit reduced anogenital distance

BACKGROUND

Animal models of endocrine dysfunction have associated male genital defects with reduced anogenital distance (AGD). Human studies have correlated shorter AGD with exposure to putative endocrine disruptors in the environment but have not examined AGD in hypospadiac boys. We measured AGD in boys with hypospadias and those with normal genitals.

METHODS

Data were collected prospectively on boys undergoing urologic procedures at the University of California San Francisco and the Children's Hospital of Oakland, CA, USA. Data included age, race, height, weight, BMI, urologic diagnoses and AGD. To minimize any potential effects of race on observed AGD, we examined only Caucasian boys. Differences between boys with hypospadias and those with normal genitals were examined through two-tailed Student's t-tests.

RESULTS

One hundred and nineteen Caucasian boys ranging in age from 4 to 86 months underwent AGD measurement, of which 42 and 77 were boys with normal genitals and hypospadias, respectively. The mean (±SD) AGD of boys with hypospadias was 67 ± 1.2 versus 73 ± 1 mm for boys with normal genitals (P = 0.002). In these age-unmatched patient groups, there were also differences in age, height and weight (P = 0.0001, 0.0002 and 0.0004, respectively). After age matching (all <2 years of age), boys with hypospadias (n= 26) still featured a shorter AGD than boys with normal genitals (n= 26; 62 ± 2 versus 68 ± 2 mm respectively, P = 0.033) but the differences in age, height and weight were no longer significant.

CONCLUSIONS

In humans, hypospadias may indeed be associated with reduced AGD. Additional studies are needed to corroborate these preliminary findings and to determine their etiology.

Expression of estrogen receptor alpha and beta is decreased in hypospadias

PURPOSE

Estrogenic endocrine disruptors acting via estrogen receptors α and β have been implicated in the etiology of hypospadias. However, the expression and distribution of estrogen receptors α and β in normal and hypospadiac human foreskins is unknown. We characterized the location and expression of estrogen receptors α and β in normal and hypospadiac foreskins.

MATERIALS AND METHODS

We prospectively collected excess foreskin from 35 patients undergoing hypospadias repair and 15 patients undergoing elective circumcision. Hypospadias was classified as severe in 18 patients and mild in 17 based on the ectopic position of the meatus. mRNA expression levels in estrogen receptors α and β were quantified using reverse transcriptase polymerase chain reaction. Receptor location was characterized by immunohistochemical analysis. Additionally immunohistochemical analysis was performed in 4 archived human fetal penises.

RESULTS

Mean ± SD ages were similar for the circumcision (9.5±3 months) and hypospadias repair groups (9±3 months, p=0.75). mRNA expression levels in estrogen receptors α and β were significantly decreased in hypospadiac foreskin cases compared to controls (p<0.001), while no statistically significant differences were seen between foreskins with severe and mild hypospadias. Estrogen receptor β immunostaining was strong in normal foreskin but weak in hypospadiac foreskin. Estrogen receptor β immunoreactivity was most intense in the stratum basale and stratum spinosum. Estrogen receptor α immunostaining was weak in normal and mild hypospadias foreskin, and undetectable in severe hypospadias. Fetal penises expressed strong estrogen receptor β immunopositivity in the urethral plate epithelium, corpus spongiosum, corpora cavernosa and penile skin, while estrogen receptor α immunostaining was not detected.

CONCLUSIONS

These data demonstrate a difference in estrogen receptor α and β expression and location in the foreskin of patients with hypospadias compared to controls. These findings are consistent with aberrant estrogenic effects having a role in the etiology of hypospadias.

New insights on the morphology of adult mouse penis

The adult mouse penis represents the end point of masculine sex differentiation of the embryonic genital tubercle and contains bone, cartilage, the urethra, erectile bodies, several types of epithelium, and many individual cell types arrayed into specific anatomical structures. Using contemporary high-resolution imaging techniques, we sought to provide new insights to the current description of adult mouse penile morphology to enable understanding of penile abnormalities, including hypospadias. Examination of serial transverse and longitudinal sections, scanning electron microscopy, and three-dimensional (3D) reconstruction provided a new appreciation of the individual structures in the adult mouse penis and their 3D interrelationships. In so doing, we discovered novel paired erectile bodies, the male urogenital mating protuberance (MUMP), and more accurately described the urethral meatus. These morphological observations were quantified by morphometric analysis and now provide accurate morphological end points of sex differentiation of mouse penis that will be the foundation of future studies to identify normal and abnormal penile development.

Diagnostic imaging in cryptorchidism: utility, indications, and effectiveness

BACKGROUND

Cryptorchidism (undescended testis) is the most common genitourinary anomaly in male infants.

METHODS

We reviewed the available literature on the diagnostic performance of ultrasound, computed tomography, and magnetic resonance imaging (MRI) in localizing undescended testes.

RESULTS

Ultrasound is the most heavily used imaging modality to evaluate undescended testes. Ultrasound has variable ability to detect palpable testes and has an estimated sensitivity and specificity of 45% and 78%, respectively, to accurately localize nonpalpable testes. Given the poor ability to localize nonpalpable testes, ultrasound has no role in the routine evaluation of boys with cryptorchidism. Magnetic resonance imaging has greater sensitivity and specificity but is expensive, not universally available, and often requires sedation for effective studies of pediatric patients. Diagnostic laparoscopy has nearly 100% sensitivity and specificity for localizing nonpalpable testes and allows for concurrent surgical correction.

CONCLUSIONS

Although diagnostic imaging does not have a role in the routine evaluation of boys with cryptorchidism, there are clinical scenarios in which imaging is necessary. Children with ambiguous genitalia or hypospadias and undescended testes should have ultrasound evaluation to detect the presence of müllerian structures.

Hypospadias: interactions between environment and genetics

Hypospadias is one of the most common congenital malformations. It is considered to be a mild form of the 46,XY disorders of sex development (DSD), but its precise etiology remains to be elucidated. Compromised androgen synthesis or effects can cause this frequent malformation, although the mutational analyses of the genes involved in androgen actions have identified abnormalities in only a very small portion of patients. The overwhelming majority of cases remain unexplained and hypospadias may be a highly heterogeneous condition subject to multiple genetic and environmental factors. We here review the recent advances in this field and discuss the potential interactions between the environment and genetics.

Ovarian pathology for the pediatric urologist

OBJECTIVES

To report the breadth of ovarian conditions that pediatric urologists may encounter through diverse referral patterns.

METHODS

Two regional pediatric centers reviewed cases from 2000 to 2010, yielding 13 females with gonad-related conditions.

RESULTS

Six of 13 patients (46%) were referred for a presumed urological condition that was later discovered to be of ovarian origin or were already known to the urology clinic for a congenital urological anomaly. Six patients had tumor markers drawn, all of which were normal. Median age was 11.2 years. The most common presenting symptoms were pain (6/13), emesis (5/13), and precocious puberty (2/13). Median mass diameter was 7.5 cm with 2 patients having masses greater than 20 cm. Histologic diagnosis was mature teratoma (4/13), streak gonad (3/13), and hemorrhagic cyst (2/13). Two patients had potentially malignant tumors (immature teratoma and juvenile granulosa cell tumor).

CONCLUSIONS

At our centers, an ovarian condition is encountered an average of 1.3 times per year. As management of pediatric ovarian cysts and masses is controversial, pediatric urologists should be familiar with the diagnosis and treatment of such conditions.

Congenital adrenal hyperplasia due to steroid 21-hydroxylase deficiency: an Endocrine Society clinical practice guideline

OBJECTIVE

We developed clinical practice guidelines for congenital adrenal hyperplasia (CAH).

PARTICIPANTS

The Task Force included a chair, selected by The Endocrine Society Clinical Guidelines Subcommittee (CGS), ten additional clinicians experienced in treating CAH, a methodologist, and a medical writer. Additional experts were also consulted. The authors received no corporate funding or remuneration.

CONSENSUS PROCESS

Consensus was guided by systematic reviews of evidence and discussions. The guidelines were reviewed and approved sequentially by The Endocrine Society's CGS and Clinical Affairs Core Committee, members responding to a web posting, and The Endocrine Society Council. At each stage, the Task Force incorporated changes in response to written comments.

CONCLUSIONS

We recommend universal newborn screening for severe steroid 21-hydroxylase deficiency followed by confirmatory tests. We recommend that prenatal treatment of CAH continue to be regarded as experimental. The diagnosis rests on clinical and hormonal data; genotyping is reserved for equivocal cases and genetic counseling. Glucocorticoid dosage should be minimized to avoid iatrogenic Cushing's syndrome. Mineralocorticoids and, in infants, supplemental sodium are recommended in classic CAH patients. We recommend against the routine use of experimental therapies to promote growth and delay puberty; we suggest patients avoid adrenalectomy. Surgical guidelines emphasize early single-stage genital repair for severely virilized girls, performed by experienced surgeons. Clinicians should consider patients' quality of life, consulting mental health professionals as appropriate. At the transition to adulthood, we recommend monitoring for potential complications of CAH. Finally, we recommend judicious use of medication during pregnancy and in symptomatic patients with nonclassic CAH.

Morphology of mouse external genitalia: implications for a role of estrogen in sexual dimorphism of the mouse genital tubercle

PURPOSE

We examined the role of androgens and estrogens in mammalian sexual differentiation by morphological characterization of adult wt and mutant mouse external genitalia. We tested the hypothesis that external genitalia development depends on androgen and estrogen action.

MATERIALS AND METHODS

We studied serial sections of the external genitalia of the CD-1 and C57BL6 wt strains of adult mice (Charles River Laboratories, Wilmington, Massachusetts). We recorded linear measurements of key structures in each specimen, including the urethra, erectile tissue, bone and cartilage. We used similar methodology to analyze mice mutant for estrogen receptor α (αERKO) and androgen receptor (X(Tfm)/Y) (Jackson Laboratory, Bar Harbor, Maine).

RESULTS

Morphology in X(Tfm)/Y adult murine external genitalia was remarkably similar to that in wt females. Bone and clitoral length was similar in wt females and X(Tfm)/Y mice. Conversely the αERKO clitoris was 59% longer and bone length in αERKO females was many-fold longer than that in female wt mice or X(Tfm)/Y mutants. The αERKO clitoris contained cartilage, which is typical of the wt penis but never observed in the wt clitoris. Serum testosterone was not increased in female αERKO mice 10 days postnatally when sex differentiation occurs, suggesting that masculinization of the αERKO clitoris is not a function of androgen.

CONCLUSIONS

Masculinization of the αERKO clitoris suggests a role for estrogen in the development of female external genitalia. We propose that normal external genital development requires androgen and estrogen action.

Penile embryology and anatomy

Knowledge of penile embryology and anatomy is essential to any pediatric urologist in order to fully understand and treat congenital anomalies. Sex differentiation of the external genitalia occurs between the 7and 17 weeks of gestation. The Y chromosome initiates male differentiation through the SRY gene, which triggers testicular development. Under the influence of androgens produced by the testes, external genitalia then develop into the penis and scrotum. Dorsal nerves supply penile skin sensation and lie within Buck's fascia. These nerves are notably absent at the 12 o'clock position. Perineal nerves supply skin sensation to the ventral shaft skin and frenulum. Cavernosal nerves lie within the corpora cavernosa and are responsible for sexual function. Paired cavernosal, dorsal, and bulbourethral arteries have extensive anastomotic connections. During erection, the cavernosal artery causes engorgement of the cavernosa, while the deep dorsal artery leads to glans enlargement. The majority of venous drainage occurs through a single, deep dorsal vein into which multiple emissary veins from the corpora and circumflex veins from the spongiosum drain. The corpora cavernosa and spongiosum are all made of spongy erectile tissue. Buck's fascia circumferentially envelops all three structures, splitting into two leaves ventrally at the spongiosum. The male urethra is composed of six parts: bladder neck, prostatic, membranous, bulbous, penile, and fossa navicularis. The urethra receives its blood supply from both proximal and distal directions.

Does severity of renal scarring on DMSA scan predict abnormalities in creatinine clearance?

OBJECTIVES

To examine the relationship between severity of renal scarring and creatinine clearance. Existing studies on renal scarring and functional outcomes have focused on the presence or absence of scarring.

METHODS

Patients with a history of urinary tract infection leading to the diagnosis of vesicoureteral reflux were recruited. These subjects were admitted to a pediatric research center for an in-patient collection of 24-hour urine to be sent for creatinine and protein. DMSA scans performed at least 6 months after documented urinary tract infection were graded by 3 independent, blinded pediatric urologists for renal scarring according to the Randomized Intervention for Children with Vesicoureteral Reflux study criteria.

RESULTS

Twenty-nine subjects (14 girls, 15 boys) with a median age of 7 years were recruited. Scar grading was reliable between the observers with a Kappa score of 0.66-0.75. On DMSA scan, 10% were scar-free, 62% had unilateral scars, and 28% had bilateral scars. Mean creatinine clearance was 123 for those with unilateral disease and 100 for those with bilateral disease (P = .048). Median proteinuria (58 mg/dL) and serum creatinine (0.5 mg/dL) were similar between the 2 groups. Creatinine clearance did not differ according to average scar grade, taking both kidneys into account.

CONCLUSIONS

In children with vesicoureteral reflux, although those with bilateral scarring have a significantly lower creatinine clearance than those with unilateral scarring, the severity of scar grade alone does not predict overall creatinine clearance with short-term follow-up.

Environmental factors in genitourinary development

PURPOSE

In the last century the world has experienced an increase in the use of industrial chemicals as well as possible increases in the prevalence of hypospadias and cryptorchidism. Because hormones regulate the fetal development of many organs, numerous investigations have explored the role of environmental factors in genitourinary growth. We summarize the data regarding endocrine disruptors in human genitourinary development.

MATERIALS AND METHODS

A PubMed literature search was performed for human studies from 2004 to 2009.

RESULTS

Few data exist on environmental influences on the kidneys, ureters or bladder. Studies on the influence of pesticides, vegetarian diets, diethylstilbestrol, oral contraceptives and corticosteroids on hypospadias have yielded varied conclusions. Phthalates appear to increase the odds of hypospadias and anogenital distance. The testicular dysgenesis syndrome postulates that cryptorchidism, hypospadias, poor semen quality and testicular cancer share a common environmental origin. In utero exposure to diethylstilbestrol has been shown to increase the risk of testicular dysgenesis syndrome. However, to our knowledge no other environmental factor has been shown to cause testicular dysgenesis syndrome. Some industrial chemicals as well as the pesticide dichloro-diphenyl-trichloroethane have detrimental effects on semen quality. In cases of documented industrial accidents, chemical exposure has also decreased the male-to-female birth ratio.

CONCLUSIONS

Data on chemical exposure are largely mixed and inconclusive. Studies of populations with high exposure rates due to industrial accidents or in utero exposure to diethylstilbestrol suggest that endocrine disruptors adversely affect genitourinary development.

Signalling molecules involved in mouse bladder smooth muscle cellular differentiation

Mouse bladder mesenchyme differentiates into smooth muscle under the influence of urothelium at gestational day 13.5 (E13.5). Sonic hedgehog (Shh) is considered to be the upstream gene arising from the urothelium, which induces smooth muscle in the peripheral bladder mesenchyme. We hypothesize differential gene expression across the full thickness of bladder mesenchyme as a function of proximity to the inducing bladder urothelium and the peripheral location of the smooth muscle. Embryonic bladders from FVB mice were collected at E12.5, 13.5, 15 and 16 and cryosectioned followed by microdissection with a PixCell II laser capture microscope. RNA extraction was performed at the laser captured sites and mRNA expression profiles were measured using SYBR Green quantitative RT-PCR. Smooth muscle a-actin (SMAA) and smooth muscle myosin heavy chain (SM-MHC) were expressed in the E13.5, E15 and E16 bladders in the peripheral layer of mesenchyme, but not in the prospective submucosa. Patched 1 (Ptc1), Gli1 and bone morphogenetic protein (Bmp) 4 expression was consistently elevated in the mesenchymal layer immediately adjacent to the urothelium compared to the peripheral location at E12.5. After E12.5, Ptc1 expression decreased to an undetectable level throughout the bladder mesenchyme. The level of TGF-beta1 was highest in the mesenchymal layer adjacent to the serosa at E13.5. The level of expression of serum response factor (SRF) was also highest at E15 in the peripheral mesenchyme. Genes downstream of Shh are differentially expressed in the prospective submucosa vs. the peripheral bladder mesenchyme as a function gestation age and smooth muscle differentiation.

Long-term survival and renal transplantation in a monozygotic twin with cloacal dysgenesis sequence

Cloacal dysgenesis sequence (CDS) is a severe hindgut malformation occurring in 1:50,000 to 250,000 live births (Qureshi et al. Prenatal diagnosis of cloacal dysgenesis sequence: differential diagnosis from other forms of fetal obstructive uropathy. Fetal Diagn Ther 1998;13:69-74; Bargaje et al. Cloacal dysgenesis sequence. Ann Diagn Pathol 2008;12:62-66). It is characterized by a smooth perineum with no urethral, vaginal, or anal openings, and lack of labioscrotal development. Typically, the bladder, vagina, and colon each end blindly, although persistent cloaca without perineal orifice can be seen. With no egress for urine, infants have renal insufficiency and pulmonary hypoplasia, usually making CDS lethal (Sahinoglu Z et al. The prenatal diagnosis of cloacal dysgenesis in six cases: can the termination of pregnancy always be the first choice? Prenat Diagn 2004;24:10-16). Reported survivors have had a persistent urachus or have been spared the effects of oligohydramnios by the presence of a twin (Liang X. Cloacal dysgenesis sequence: observations in four patients, including three fetuses of second trimester gestation. Pediatr Dev Pathol 1998;1:281-288). We report a case of long-term survival, currently to 25 months of age, and renal transplantation in a monochorionic, diamniotic twin girl with CDS.

Estrogen effects on fetal penile and urethral development in organotypic mouse genital tubercle culture

PURPOSE

We developed an organotypic genital tubercle culture system in vitro and used it to investigate the direct effects of the hyperestrogenic state on fetal mouse penile and urethral development.

MATERIALS AND METHODS

Genital tubercles were dissected from embryonic day 14.5 C57B/L6 male mouse fetuses and cultured using an air-liquid interface on a microporous membrane support soaked in synthetic medium. Cultures were separated into 4 groups. Groups 1 to 3 were supplied with 10 nM dihydrotestosterone, estradiol and 10 nM dihydrotestosterone plus estradiol, respectively. Group 4 was cultured in hormone-free medium. After 36 to 72-hour culture morphological, histological, proliferation, apoptosis, androgen signaling and activating transcription factor 3 analyses were done.

RESULTS

The physiological concentration of 10 nM dihydrotestosterone was essential for genital tubercle growth in vitro. Androgen induced growth and urethral development were significantly suppressed by high dose estrogen. Concurrently we observed increased apoptosis and decreased proliferation in the mesenchyma. Androgen signaling was disrupted and activating transcription factor 3, a factor related to hypospadias genesis, was up-regulated.

CONCLUSIONS

High dose estrogen suppressed male genital tubercle development in vitro. The organotypic genital tubercle culture system in vitro consisting of urethral epithelial and mesenchymal cells can recapitulate the hormonal sensitivity of fetal penile and urethral development. This method is potentially useful for studying the effects of various factors, particularly endocrine disruptors.

46, XY female with cloacal exstrophy and masculinization at puberty

Cloacal exstrophy of the bladder is a rare complex disorder occurring 1 in 400,000 live births and associated with cryptorchidism, vesicoureteral reflux, severe phallic inadequacy, omphalocele with short-gut syndrome, exstrophied bladder separated by exstrophied ileocecal segment, and pubic symphyseal diastasis. The association of undescended and ectopic testis with cloacal exstrophy is not uncommon, but the presence of an unexpected persistent ectopic testis at the time of puberty is quite unusual. We report the case of a 17-year-old girl with a history of 46, XY cloacal exstrophy and gender reassignment presenting with an ectopic testis of unclear location. We then review controversial literature surrounding gender assignment in these patients.