Invasive Squamous Cell Carcinoma Arising in Long-Standing Chromoblastomycosis Requiring Limb Amputation: A Case Report

Chromoblastomycosis is a chronic granulomatous infection of the skin and subcutaneous tissue caused by melanized fungi introduced through traumatic implantation. Although typically indolent, long-standing lesions may undergo malignant transformation into squamous cell carcinoma (SCC). We report a 77-year-old man with a 10-year history of a verrucous lesion on the right foot, which progressively enlarged and evolved into a non-healing ulcer. Histopathological examination revealed a well-differentiated invasive SCC infiltrating the reticular dermis, associated with dense fibrosis, chronic granulomatous inflammation, and numerous muriform bodies consistent with chromoblastomycosis. Due to extensive tissue destruction and functional impairment, lower limb amputation was performed. This case highlights the carcinogenic potential of chronic inflammatory dermatoses and underscores the critical role of histopathological evaluation and long-term surveillance in persistent chromoblastomycosis.