Squamous Cell Carcinoma Arising From an Interdigital Pilonidal Sinus

[摘要] A 65-year-old female hairdresser reported a more than 30-year history of recurrent infections of toes IV/V on the right foot. Clinical examination revealed a pit with distal ulceration (Figure) . Initial histology showed epidermal hyperplasia with chronic inflammation, consistent with a pilonidal sinus. The differential diagnoses were bacterial or mycotic infection. A repeat biopsy after unsuccessful topical treatment and progression of the lesion revealed verrucous squamous cell carcinoma (G1) in the pilonidal sinus. The cancer was resected under micrographic guidance and the wound covered with a split skin graft. Extra-anal pilonidal sinus is a rarely described occurrence and in hairdressers usually affects the hand. A piece of hair penetrates the skin and leads to a granulomatous inflammatory reaction. This is potentiated by friction, pressure, and hyperhidrosis. Our patient reported wearing open shoes in the workplace. Squamous cell carcinoma occasionally develops from a longstanding pilonidal sinus.

[学科分类] 医学（综合）