Epidermal Inclusion Cyst After Circumcision

The parents of a 2 1/2-year-old boy were concerned about the mass on their child’s penis. They first noticed the mass around 6 months of age. It had gradually enlarged to its current size and did not appear to be bothering the child. At 1 week of age, he had undergone simultaneous bilateral inguinal hernia repair and circumcision. His postoperative visit 3 weeks after surgery revealed no abnormalities. His medical history was otherwise unremarkable. He was completely immunized for age. There was no family history of hypertrophic scar formation.

Physical examination revealed an oval, flesh-colored, well-circumscribed, nontender, firm mass on the lateral aspect of the distal foreskin at the 9 o’clock position (A). Of note, the boy had well-healed hypopigmented bilateral inguinal scars, with no evidence of scar hypertrophy or keloid formation.

The mass was felt to be rather large for conservative management, and the patient was referred to pediatric surgery. The lesion was completely excised under general anesthesia and sent for pathological evaluation. Findings revealed a 1.5 3 1.0 3 0.9-cm, thin-walled cyst filled with pale, gray-tan, dusky debris. The cyst wall was less than 0.1 cm in thickness, and there were no surface excrescences on the interior. Histopathology showed proliferation of epidermal cells within a circumscribed dermal space, consistent with an epidermal inclusion cyst (B).

Complications of male circumcision are relatively rare despite the number of procedures performed.
Authors of a recent meta-analysis stated a median complication frequency of 1.5%, with a range of 0% to 16%.¹ The complications can be divided into 2 groups: early and late.² The most common early complications include bleeding, wound infection, and meatal swelling. Less common early complications are urinary retention and penile or urethral injury. Late complications include excess foreskin, shortage of penile foreskin, phimosis, penile curvature or torsion, meatal ulcer or stenosis, lymphedema, and inclusion cysts of surrounding penile skin. An epidermal inclusion cyst after circumcision is extremely rare, even in areas with relatively higher rates of complication.³

Epidermal inclusion cysts (epidermoid cysts) of the face, scalp, neck, trunk, and extremities are common. Congenital epidermoid cysts may rarely occur in close proximity to the frenulum of the penis and are thought to result from abnormal embryologic closure of the median raphe.⁴ Acquired epidermoid cysts of the genitalia are more commonly described in the context of female circumcision.⁵ Certain syndromes, such as Gardner syndrome and basal cell nevus syndrome, are associated with the formation of epidermoid cysts.

In the differential diagnosis of penile epidermal inclusion cysts, urethral diverticula can be excluded
with a voiding cystourethrogram. Other lesions, such as sebaceous cysts and keloids, can be made on the basis of the histopathology after excision. In this patient, the lack of keloids or hypertrophic scar formation made the diagnosis of keloids less likely.

Inclusion cysts may be asymptomatic when small. Larger cysts can cause significant morbidity from urethral obstruction, painful intercourse, or cosmetic issues.⁶ Although cases of epidermal inclusion cysts with progression to skin cancer have been reported, none involved penile cysts.

Treatment of penile epidermal inclusion cysts consists of complete excision with primary closure. The risk of recurrence is very low with successful excision. The lesion may recur after excision in patients with residual cyst tissue and after simple aspiration and drainage.