A. Pilonidal sinus
Surgical incision revealed multiple protruding hairs. The lesion was excised and sent for histopathological analysis, which revealed a sinus tract in the dermis lined by stratified epithelium and filled with hair shafts, surrounded by a lymphoplasmacytic inflammatory infiltrate (Figure, D). The wound healed by secondary intention, and the patient had a successful recovery with no signs of recurrence at 6-month follow-up.
A pilonidal sinus is a benign tract that contains hair fragments and extends from a skin-lined opening into the subcutaneous tissue. It is a chronic inflammatory condition most frequently located in the natal or gluteal cleft; this is why the condition was initially thought to be congenital. However, there is now consensus that pilonidal sinus is an acquired lesion.1 Some authors propose that local trauma and friction produce subcutaneous trapping of hair, leading to the formation of a cyst and then a sinus to drain the suppuration.1,2 However, more current reports suggest that these lesions may be localized forms of hidradenitis suppurativa.3- 5 Pilonidal sinuses in unusual locations have been reported, including the scalp, neck, abdomen, groin, axilla, and even amputation stumps; these locations correlate with the classic sites of hidradenitis suppurativa. However, penile involvement is considered rare.6,7 The few reported cases all occur in uncircumcised men, suggesting that the prepuce plays a role in the mechanical forces needed for the implantation of hair; other factors, such as shaving, high body mass index, and hirsutism, have also been proposed as contributory. Clinical presentation varies and includes penile papules and swelling; in complicated cases, there may be abscess formation, coinfection, and even ulceration mimicking sexually transmitted infections and penile carcinoma.8 Additional findings that may point to the diagnosis are hair protruding from the cavity and a central orifice on dermoscopy.9 Treatment is surgical with excision of the tract and healing by secondary intention.