RESUMO
PURPOSE: Subungual squamous cell carcinoma is a very rare malignant tumor of the digitus especially in toe making it very difficult to differentiate from tinea unguium, verruca vulgaris, eczema, pyogenic granuloma, and malignant melanoma due to their clinical similarities. Therefore this article reports on subungual squamous cell carcinoma of left 5th toe. METHODS: A patient visited at our hospital due to pain and incurable inflammation on left 5th toe with no improvement for four months. Despite of antibiotics and dressing for a week, treatment was ineffective. After excisional biopsy, he was diagnosed with subungual squamous cell carcinoma. And ray amputation and prophylactic inguinal lymph node dissection was done. RESULTS: The biopsy was showed irregular cells made up of anaplastic and squamous cells in the dermis and epidermis. And the inguinal lymph node showed no metastasis. The patient had been treated without significant complications or recurrence for a year. CONCLUSION: This article emphasizes the need of diagnostic biopsy on the subungual lesions that have resistance to the conventional treatments. And if that is subungual squamous cell carcinoma, complete resection of the lesion and prophylactic inguinal lymph node dissection is essential.