DERMATOFIBROMA OF THE GREAT TOE – A RARE CASE REPORT

Dermatofibroma (DF), also referred to as cutaneous fibrous histiocytoma (CFH), is a common benign tumor of the skin presenting as a firm nodule located predominantly on the limbs and shoulder and pelvic girdles that often extends into superficial subcutaneous tissue. Dermatofibroma has many clinicopathological variants. This report presents a case of a dermatofibroma on a great toe that had been slowly growing for four years. Histopathologically, the relatively well-circumscribed dermal tumor was separated from the epidermis by a small grenz zone. The tumor tissue consisted of spindle-shaped cells with well-defined cell borders and spindly condensed nuclei. No cytologic atypia or mitotic figures were found. Immunohistochemically, the tumor cells showed negative staining for CD34 and S-100. Histopathological differential diagnoses of dermatofibroma include superficial acral fibromyxoma, cellular digital fibroma, superficial angiomyxoma, myxoid dermatofibrosarcoma protuberans and low-grade fibromyxoid sarcoma. Immunohistochemical staining can be useful in the differential diagnosis of these tumors. Pathologists should keep in mind the diagnosis of dermatofibroma when dealing with circumscribed, firm nodules presenting on the digits.