What is hypospadias and how is it diagnosed?
Hypospadias is a congenital malformation of the male external genitalia in which abnormal development of the urethral fold and ventral foreskin places the urethral opening (meatus) on the underside of the penis, anywhere between the glans and the perineum. It is the commonest penile congenital anomaly and the second commonest congenital disorder in boys after cryptorchidism. The US incidence is about 1 in 250 male births.
Diagnosis is clinical and made soon after birth. Key features are an abnormally placed ventral meatus, a dorsal hood of foreskin with an incomplete prepuce ventrally, and sometimes chordee (abnormal curvature of the penis). In mild forms the urinary stream is normal; in severe forms the meatus may be narrowed and the stream directed downward. If the baby has a complete foreskin, hypospadias may only be noticed at circumcision.
How is hypospadias classified?
Hypospadias is classified by the position of the meatus. The commonly used three-tier system divides it into anterior (glanular and subcoronal), middle (distal, midshaft and proximal penile) and posterior (penoscrotal, scrotal and perineal). A simpler form uses distal, midshaft and proximal. Overall the subcoronal position is the commonest site, and distal hypospadias makes up 60% to 70% of cases.
| Group | Meatus lies at | Remarks |
|---|---|---|
| Anterior (distal) | Glanular, coronal or subcoronal | Most common (60% to 70% as 'distal'); little effect on the stream |
| Middle (penile) | Distal, midshaft or proximal penile shaft | May have chordee |
| Posterior (proximal) | Penoscrotal, scrotal or perineal | Chordee common; most often associated with other genitourinary anomalies |
In one StatPearls breakdown, nearly 50% of cases are anterior, 20% middle and the rest posterior. Whatever the position, many boys have a hooded foreskin: abundant prepuce dorsally and scant or absent prepuce ventrally.
What causes hypospadias and what is the embryology?
The exact cause is unknown; genetic, endocrine and environmental factors are all implicated. Inheritance is considered polygenic, and risk is higher with a family history. Hypospadias is common in males with low androgen levels or reduced androgen receptor sensitivity. Prenatal exposure to oestrogen-like compounds with antiandrogenic activity has also been proposed.
The key event is anomalous or incomplete closure of the urethral folds in the early weeks of development. External genital development has two phases. Between weeks 5 and 8 the primordial genitalia form without hormonal stimulation: cloacal folds fuse anteriorly to form the genital tubercle and split posteriorly into urogenital and anal folds. The second phase is hormone-dependent: once the testes differentiate in an XY embryo, testosterone drives elongation of the genital tubercle and appearance of the urethral groove. The urethra forms when the urethral folds fuse, and the skin fusing along the ventral midline forms the median raphe.
Which anomalies are associated with hypospadias and when is a work-up needed?
Most hypospadias is an isolated malformation, but it can occur with other genitourinary anomalies, mainly in the proximal forms. The commonest associations are cryptorchidism (8% to 10%) and inguinal hernia (9% to 15%). Vesicoureteral reflux, pelviureteric junction obstruction and renal anomalies such as pelvic or horseshoe kidney are seen mostly in proximal hypospadias. Hypospadias is a feature of up to 200 syndromes, including WAGR, Denys–Drash, Smith–Lemli–Opitz, Wolff–Hirschhorn and CHARGE.
| Situation | Action |
|---|---|
| Distal or midshaft hypospadias alone | Surgical referral; no imaging or extra work-up (renal anomaly risk is similar to the general population) |
| Proximal hypospadias | Look for other genitourinary anomalies; renal, bladder and abdominal ultrasound |
| Hypospadias with one or both undescended testes | Order a karyotype to exclude a disorder of sex development |
An older child with an angled penis may have painful erections and, as an adult, problems with ejaculation or intercourse. For related topics see undescended testis and scrotal swellings and development of the genitourinary system.
How and when is hypospadias repaired?
Surgery is the only definitive treatment. The aims are to straighten the penis (correct chordee), create a urethra with a meatus of adequate calibre at the tip of the glans, and obtain a cosmetically normal appearance. Affected boys should be referred for surgical evaluation within the first weeks of life, and repair is advised between 6 and 18 months of age. Late repair carries more complications, including urethrocutaneous fistula.
- Distal and midshaft hypospadias: usually a single-stage repair; recent advances allow single-stage repair in children under 12 months.
- Proximal hypospadias with chordee: commonly a two-stage repair, with urethroplasty and penile straightening first and tubularisation of the urethral plate later.
- Preoperative testosterone is sometimes given to increase penile size and reduce dehiscence, but there are no specific guidelines for its use.
The prognosis has improved over the past three decades. Short-term results are good, but StatPearls notes that long-term results are guarded, as some adults remain concerned about cosmesis and sexual function.
What is bladder exstrophy and the exstrophy–epispadias complex?
Bladder–exstrophy–epispadias complex (BEEC) is a spectrum of defects of the lower abdominal wall, urinary tract, genitalia and bony pelvis. At the mild end is epispadias; classical bladder exstrophy is in the middle; and cloacal exstrophy is the most severe. Classical exstrophy occurs in roughly 2 to 3.3 per 100,000 live births, and boys are affected more often than girls (about twice as often in most series).
The most accepted theory (Marshall and Muecke) is an abnormally large cloacal membrane that acts as a wedge and prevents the mesenchyme from migrating to the midline. The lower abdominal wall does not form properly, and rupture of the membrane lets the bladder open onto the surface. Maternal smoking and first-trimester irradiation raise the risk of the severe forms, and periconceptional folate lowers it.
| System | Finding |
|---|---|
| Bladder | Red fleshy bladder plate bulging in the suprapubic region with continuous urine leakage; ureteric orifices often visible (do not probe them) |
| Bony pelvis | Open-book pelvis: pubic diastasis about 4 cm at birth (normal under 1 cm), anterior pelvic segments about 30% shorter, outward rotation |
| Male genitalia | Short, broad phallus with dorsal chordee, epispadias, flattened glans; undescended testis and bilateral inguinal hernias may be present |
| Female genitalia | Bifid clitoris, anteriorly placed vaginal opening; uterine or vaginal duplication not uncommon |
| Other | Anteriorly displaced anus from pelvic floor abnormalities; all pelvic organs are displaced anteriorly |
How does epispadias differ from hypospadias?
| Feature | Hypospadias | Epispadias |
|---|---|---|
| Urethral opening | Ventral surface of the penis | Dorsal surface; open, exposed urethral plate |
| Foreskin | Dorsal hood, deficient ventrally | Ventral hooding of the prepuce |
| Penis | May have ventral chordee | Short, upward-pointing phallus |
| Frequency | Common (about 1 in 250 boys) | Rare; isolated epispadias is under 10% of the complex |
| Association | Cryptorchidism, hernia | Part of the exstrophy–epispadias complex; incontinence, reflux |
| Female | Rare | Bifid clitoris, patulous urethral meatus, ill-formed mons pubis |
How is bladder exstrophy managed?
Diagnosis is clinical, and a plain radiograph of the pelvis documents the pubic diastasis; an ultrasound of the kidneys, ureters and bladder looks for associated upper-tract anomalies, and a pelvic or perineal ultrasound looks for Müllerian anomalies in girls. Before surgery the bladder plate should be covered with a non-adherent plastic wrap or film, which protects against trauma and prevents the polyps that make closure difficult.
The goals of reconstruction are to close the bladder and create a reservoir that can store and grow, to protect the upper tracts, and to reconstruct genitalia with good continence and sexual function. Two reconstructive approaches are widely used: the modern staged repair of exstrophy (MSRE) and the complete primary repair of exstrophy (CPRE, Mitchell repair).
| Stage | Procedure | Timing |
|---|---|---|
| 1 | Bladder closure (primary turn-in); osteotomy may be avoided | First 3 days of life |
| 2 | Epispadias repair (genital reconstruction) | 6 to 9 months |
| 3 | Bladder neck reconstruction | About 4 to 5 years, when bladder capacity is at least 100 mL and the child can take part in voiding training |
CPRE performs bladder closure, bladder neck repair and epispadias repair together in a single operation (complete penile disassembly), aiming to start early bladder cycling and avoid later operations. The commonest complications of surgery are wound dehiscence and bladder dehiscence; osteotomy at closure reduces tension and helps prevent them. Long-term, there is a 1% to 2% risk of bladder malignancy, and adenocarcinoma is the commonest type, even in unrepaired bladders.
What are the common exam traps?
- Ventral = hypospadias; dorsal = epispadias. Dorsal chordee and an upward-pointing penis point to the exstrophy-epispadias complex.
- Circumcision is contraindicated in hypospadias because the foreskin is used for repair.
- Most hypospadias is distal and needs no imaging; proximal hypospadias with undescended testes needs a karyotype and renal ultrasound.
- Ideal repair age is 6 to 18 months.
- In exstrophy, the pubic symphysis is widely separated (open-book pelvis), and the anus is placed anteriorly.
- Do not cannulate the ureteric orifices on the exposed bladder plate; cover the plate with plastic wrap.
- Adenocarcinoma is the characteristic late malignancy in bladder exstrophy.
Related pages: practise previous papers at NEET PG Surgery PYQs and NEET PG Pediatrics PYQs, and see the most repeated topics.