At 9-13 weeks of gestation, dihydrotestosterone (DHT) simulates androgen receptors the
Genital tubercleto differentiate into penis
Urethral folds to differentiate into the corpus spongiosum/penile shaft
Labioscrotal swellings to differentiate into scrotum
Also known as genital swellings or labioscrotal folds§
The male develops in a proximal-to-distal manner
As the penis forms from the elongation and enlargement of the phallus, the lateral walls of the urethral groove form from the ventrally located urethral folds, which then fuse in the midline.
The scrotum forms from midline fusion of the labioscrotal swellings as delineated by the scrotal raphe.
By the end of the first trimester (12 weeks), the external genitalia are completely masculinized
US sex determination after 13 weeks is accurate in 99-100% of cases of gestation without malformed external genitalia
In females and males with abnormalities in testosterone and/or DHT production, 5α-reductase deficiency, or androgen-receptor insufficiency, the
Genital tubercle passively become the clitoris
Urethral folds passively become thelabia minora
Labioscrotal swellings passively become the labia majora
See Table 146-3: Tanner Classification of Sexual Maturity Stages in Boys
Reduced risk of Sexually transmitted diseases including HIV
Reduced risk of Phimosis
Reduced risk of Balanitis
Contraindications (2):
Neonates with other penile conditions (hypospadias, penile curvature, dorsal hood deformity, buried penis, and webbed penis) that require surgical correction
Other conditions commonly seen in neonates that should be taken into consideration are a large hydrocele or inguinal hernias, which are more likely to develop secondary phimosis, buried penis, and trapped penis.
There should be complete separation of the prepuce from the glans and complete inspection of the meatus and the corona to confirm the absence of anomalies, including hypospadias.
Coagulopathy
Techniques and devices for neonatal circumcision:
Gomco clamp
Mogen clamp
Plastibell device
Complications (6):
Risk of complications after circumcision: 0.2-5%
Bleeding
Most common complication, occurs in 0.1% and is more common in older children
Usually localized from the frenulum
Wound infection
Rare complication
Antibiotic ointment (e.g., bacitracin) after circumcision usually prevents its development
Penile skin complications
Insufficient or asymmetrical excision can result in a cosmetic and social dilemma for the parents and child
Excessive skin excision can result in:
Penile chordee, torsion, and lateral deviation
Trapped penis from a cicatricial scar
Glanular adhesions and skin bridges
Glanular adhesions and skin bridges, attachments of the glans and penile shaft, respectively, are common complications
Both can occur in the well-circumcised penis and areusually the result of the physiologic retraction of the penis caused by a suprapubic fat pad and diaper irritation of the penis
Management
Persistent adhesions can be lysed in the office with the application of a topical analgesic such as EMLA cream
Low-dose corticosteroids have been relatively unsuccessful in lysing adhesions
Meatal Stenosis
The normal urethral meatus is:
Age<4: 10 Fr
Age 4-10: 12 Fr
Age>10: 14 Fr
Symptoms include:
Narrow, high-velocity stream
Urinary stream deviation, typically in an upward direction resulting from a meatal baffle or ventral web located at the inferior aspect of the meatus
Penile painat the initiation of micturition
Penile Trauma
Most serious complication
Includes urethral injury, excision of the glans and/or penile shaft, and penile necrosis
Urethral injury requires urethroplasty
Excision of the glans can be repaired by suturing the excised tissue back to the penis, often without the need for microscopic repair
Penile agenesis results from failure of development of the genital tubercle
The karyotype almost always is 46,XY, and the usual appearance is that of a well-developed scrotum with descended testes and an absent penile shaft.
Associated malformations are common and include cryptorchidism, vesicoureteral reflux, horseshoe kidney, renal agenesis, imperforate anus, and musculoskeletal and cardiopulmonary abnormalities
Testing should include a karyotypeand other appropriate studies to detect associated malformations of the urinary tract or other organ systems.
MRI may be beneficial in determining the severity of the defect
Definition of inconspicuous penis: penis that appears to be small but with normal stretched penile length measured from the pubic symphysis to the tip of the glans and normal diameter of the penile shaft
Differentiated from micropenis, in which the penis is abnormally small
Subtypes (3): buried penis, webbed penis, and trapped penis
Buried Penis
Definition of a buried penis: a normally developed penis that is hidden away by a suprapubic fat pad
Classified into 3 categories based on cause of the concealment:
Poor penopubic fixation of the skin at the base of the penis
Obesity
A trapped penis from cicatricial scarring after penile surgery, typically a circumcision
May occur after neonatal circumcision in an infant with significant scrotal swelling as a result of a hernia or hydrocele or after routine circumcision in an infant with a webbed penis
Insert figure
Management
Based on the cause
The trapped penis can be managed with betamethasone, vertical relaxation incision, and formal repair
Webbed Penis
Definition of a webbed penis: a congenital or acquired condition resulting from the scrotal skin extending onto the ventrum of the penis
Definition of micropenis: a normally formed penis that is at least 2.5 standard deviations (SD) below the mean size in stretched length for age
Stretched penile length correlates more closely with erectile length than does the relaxed penile length and should be compared with standards for penile length
Micropenis in the full-term neonate is stretched penile length <1.9 cm long
Causes
See CW11 Box 146-1: Etiology of Micropenis
Results from a hormonal abnormality that occurs after 14 weeks of gestation
Hypogonadotropic hypogonadism (most common cause)
Failure of the hypothalamus to produce adequate quantities of gonadotropin-releasing hormone (GnRH) can occur in Prader-Willi syndrome, Kallmann syndrome (genital-olfactory dysplasia), Laurence-Moon-Biedl syndrome, and the CHARGE association
Often associated with major chromosomal defects, including: Klinefelter syndrome (47,XXY) and other X polysomy syndromes, deletions, translocations, and trisomy involving chromosomes 8, 13, and 18
Initial evaluation of a child with micropenis includes a history, physical examination, and a karyotype at birth.
The ratio of the length of the penile shaft to its circumference is usually normal, but occasionally the corpora cavernosa are severely hypoplastic. The testes are usually small and frequently cryptorchid, whereas the scrotum is usually fused and often diminutive
Although ultimate penile size may be below the normal range, men born with micropenis have male gender identity and most have satisfactory sexual function
Results from disproportionate development of the tunica albuginea of the corporal bodies
Not associated with urethral malformation§
Most commonly in the ventral direction (as opposed to Peyronie’s which is dorsal curvature), with preserved penile length and typically normal erectile function and rigidity§
Commonly associated with hypospadias
Isolated chordee may occur with or without a dorsal hood of prepuce and is commonly associated with a deficiency of the ventral skin
Congenital dorsal penile curvature may be an isolated condition with or without asymmetrical penile skin or associated with epispadias and a ventral hood of prepuce.
Healthy young men usually present between age 18-30 when the abnormal curvature is brought to their attention from their sexual partner
Treatment is surgical and is offered to patients whose congenital penile curvatures significantly interferes with satisfactory sexual relations of the patient or partner.
A rare anomaly and appears as a small blister in proximity to the urethral meatus
Inclusion Cysts
Smegma pearl
Smegma, produced under the foreskin, is made of 27% fat and 13% protein§
A smegma pearl is a type of inclusion cyst where smegma becomes entrapped under the unretractable foreskin
See Figure
Most common acquired cystic lesion of the penis
May form after penile surgery, including circumcision and hypospadias repair, owing to islands of epithelium within the subcutaneous tissue. Excision of the epidermal inclusion is recommended.
Congenital Penile Nevi
Pigmented lesions that can form on the glans and penile shaft tend to be superficial and benign and should be excised
Juvenile Xanthogranuloma
Uncommon benign lesion of the penis
Lesions appear as solitary or multiple pigmented (yellow, orange, gold, brown, or red) nodules of rapid onset. They measure 2-20 mm in diameter and are well demarcated, firm, and rubbery.
Predominantly seen in infancy or early childhood.
The lesion is often self-limited, and a period of 1 year of expectant monitoring is advised to avoid potentially unnecessary ablative genital surgery
Duplication most commonly occurs in the sagittal plane with one urethra located ventrally and the other dorsally
Usually the dorsal urethra is considered the accessory urethra with or without a urinary stream, whereas the ventral urethra carries the urine stream and the anatomic landmarks such as the external sphincter and verumontanum.
Associated genitourinary, gastrointestinal, and musculoskeletal anomalies may be present
Vesicoureteral reflux is the most common associated anomaly
Other anomalies include renal agenesis, bilateral cryptorchidism, sacral agenesis, imperforate anus, radial hypoplasia, tracheoesophageal fistula, and other midline defects such as duplicated bladder, duplicated colon, imperforate anus and anorectal agenesis, bifid glans, thoracic hemivertebrae, and partial sacral agenesis
The most common presentation of urethral duplication is a double meatus and double urinary stream
Evaluation should include a voiding cystourethrogram, retrograde urethrogram, and direct visualization of the anatomy during cystourethroscopy
Frequently occurs in conjunction with perineal, scrotal, or penoscrotal hypospadias with chordee
Also associated with caudal regression, sex chromosome abnormalities, and Aarskog syndrome.
As many as 75% of patients with complete penoscrotal transposition and a normal scrotum have a significant urinary tract abnormality, including renal agenesis and dysplasia, and other nongenitourinary anomalies
The processus vaginalis forms during the 3rd month of gestation as the peritoneum bulges into the inguinal canal just before the onset of testicular descent.
On completion of testicular descent, the processus vaginalis obliterates and the portion adjacent to the testes becomes the tunica vaginalis
Obliteration of the processus vaginalis continues post-natally, and its failure to obliterate accounts for nearly all inguinoscrotal abnormalities seen in infancy and childhood
Patent process vaginalis is associated with (4):
Transverse testicular ectopia
Epididymal anomalies
Cryptorchidism
Polyorchidism
Risk of spermatic cord torsion is associated with abnormal development of the tunica vaginalis but not patency of the processus vaginalis
Incidence of incidental patency observed in older children and adults at autopsy or laparoscopy is ≈20%
Indirect inguinal hernia: a widely patent processus vaginalis extending beyond the internal inguinal ring containing abdominal contents (bowel, omentum, gonads) which may pass into the inguinal canal, labia, or scrotum
Communicating hydrocele: a patent processus vaginalis extending beyond the internal inguinal ring containing peritoneal fluid alone, which extends to the testis, with fluid within the tunica vaginalis
Hydrocele of the spermatic cord: fluid contained within a segment of patent processus vaginalis with obliterated processus distally and proximally
Scrotal hydrocele: fluid contained within the tunica vaginalis surrounding the testis without communication proximally
May be seen as a chronic or acute scrotal swelling after an inflammatory, infectious, or traumatic event. The hydrocele size is typically stable but may decrease over time.
Abdominoscrotal hydrocele: a large scrotal hydrocele that extends proximally across the internal inguinal ring into the abdomen without communication with the peritoneum
Inguinal hernias develop in 1-5% of children, 5-10x more common in boys and significantly more common among premature infants
More common (3:1) on the right side
Attributed to the later descent of the right testicle
Risk factors for bilateral involvement (4):
Female gender
Prematurity
Age < 1
History of cryptorchidism
Average age at presentation is 3-4 years
The majority of new hydroceles occurring after birth and before puberty are associated with a patent processus vaginalis (clinically communicating, clear history of fluctuation)
Noncommunicating Hydroceles
Hydroceles that spontaneously resolve during infancy or appear during or after puberty are more commonly non-communicating
These form from delayed fluid absorption or abnormal fluid dynamics within the tunica vaginalis
Typically manifests as a painless bulge found in the groin or extending along the cord to the scrotum.
The bulge may be present only during periods of increased intra-abdominal pressure (crying or bowel movements
The presence of an intermittent bulge helps to distinguish a reducible inguinal hernia and communicating hydrocele from a scrotal hydrocele or hydrocele of the spermatic cord.
The child with an incarcerated inguinal hernia will be irritable or inconsolable and have a persistent or larger bulge without spontaneous reduction and may have decreased appetite and signs of bowel obstruction (abdominal distention, vomiting, and lack of flatus or stool)
Physical Exam
The supine position facilitates reduction of peritoneal fluid and intra-abdominal contents
The hydrocele fluid surrounding the testicle should transilluminate; however, neonatal bowel may also transilluminate.
The hydrocele of the spermatic cord is usually painless and variable in size. It may be confused for the testis because of its round-oval shape
Require surgical repair shortly after diagnosis, given the significant risk of associated complications
Standard Inguinal Hernia Repair
The traditional surgical approach to repairing an indirect inguinal hernia or communicating hydrocele is high ligation of the hernia sac at the level of the internal inguinal ring. This carries a high success rate
In peripubertal boys with hydrocele, determine if hydrocele is communicating or scrotal.
If communicating, inguinal approach is preferred
If scrotal, trans-scrotal hydrocele approach is performed as in adults and an inguinal incision made only if a proximal communication is identified.
Complications
Early postoperative complications, including bleeding and infection, are rare after standard hernia repair
Recurrent inguinal hernia
Rate after uncomplicated open repair: 0.5-1%
Causes include failure to properly identify or ligate the sac during the original procedure; a tear in the sac, leaving a strip of peritoneum along the cord; damage to the floor; or a missed direct hernia at the original exploration.
Laparoscopic inguinal hernia repair associated with higher risk of recurrence (up to 4%) than with open repair
Secondary cryptorchidism, testicular atrophy, and vasal injury is not well defined.
If a testis is incompletely descended or retractile, orchidopexy should be performed at the time of herniorrhaphy
Assessment of the contralateral internal ring
The need to assess the patency of the contralateral processus vaginalis or of the internal inguinal ring in children with a unilateral hernia remains controversial
Congenital absence of the vas deferens (CAVD) is in most cases associated with specific mutations of the cystic fibrosis gene CFTR (cystic fibrosis transmembrane regulator) that are less severe than those encountered in patients with cystic fibrosis.
Disease can be bilateral (CBAVD) or unilateral (CUAVD) with a normal or obstructed contralateral vas
May be associated with renal agenesis or ectopia and/or partial or complete agenesis of the epididymis and seminal vesicles