Squamous Cell Carcinoma Arising From an Interdigital Pilonidal Sinus
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.
Dr. med. Jennifer Haiduk, Dr. med. Monica Schüürmann, PD Dr. med. habil. Sonja Grunewald, Universitätsklinikum Leipzig, Klinik für Dermatologie, Allergologie und Venerologie, Jennifer.Haiduk@medizin.uni-leipzig.de
Conflict of interest statement: The authors declare that no conflict of interest exists.
Translated from the original German by David Roseveare.
Cite this as: Haiduk J, Schüürmann M, Grunewald S: Squamous cell carcinoma arising from an interdigital pilonidal sinus. Dtsch Arztebl Int 2019; 116: 212. DOI: 10.3238/arztebl.2019.0212b