Abstract
Hidradenitis suppurativa (HS) is a chronic inflammatory skin disease that can lead to rare but aggressive complications, including squamous cell carcinoma (SCC), particularly in the anogenital region. Risk factors such as human papillomavirus (HPV) infection, chronic inflammation, and coexisting conditions such as psoriasis can increase the likelihood of malignant transformation in HS lesions. We report a 43-year-old man with a history of HS (Hurley stage II) and psoriasis who developed a rapidly progressing perianal SCC. The patient, a chronic smoker, tested positive for low-risk HPV type 6 and high-risk HPV type 16. Imaging revealed an extensive tumor mass infiltrating the sacral bone and surrounding tissues. Histopathology confirmed well-differentiated SCC with inguinal lymph node metastasis. The patient underwent radical surgery and radiotherapy. Laboratory findings showed monoclonal immunoglobulin G (IgG) gammopathy and secondary thrombocytosis related to chronic inflammation. SCC is a rare but serious complication of HS, particularly in the presence of chronic inflammation and HPV infection. Early detection through regular biopsies and vigilant monitoring of high-risk patients is essential. The consideration of HPV vaccination in severe HS cases, especially those undergoing immunosuppressive therapy, may reduce the risk of malignant transformation.