From chronic hidradenitis suppurativa to epidermoid carcinoma, from inflammation to cellular degeneration.

Hidradenitis suppurativa is a chronic inflammatory skin disease characterized by recurrent nodules, abscesses, and sinus tracts, most often located in axillary, inguinal, and gluteal regions. Malignant transformation into squamous cell carcinoma is a rare but serious complication. We present the case of a 50-year-old man with ˃10 years of poorly controlled hidradenitis suppurativa who developed painful gluteal discharge and multiple exophytic lesions. Imaging demonstrated large perianal and perineal masses with destruction of the coccyx, but no distant spread. Biopsy confirmed well-differentiated squamous cell carcinoma. Because of the local extent, the multidisciplinary team recommended radiotherapy as the primary treatment. Malignant degeneration of hidradenitis suppurativa is more frequent in long-standing, advanced disease, particularly in gluteal and perineal areas, and is associated with delayed diagnosis and high mortality. Early biopsy of suspicious lesions and multidisciplinary management are essential to improve prognosis.