A case of atypical fibroxanthoma of subungual type: ultrasound and magnetic resonance imaging findings

Subungual atypical fibroxanthoma is a rare mesenchymal skin tumor of intermediate malignancy. It classically presents as a relatively nondescript, erythematous nodule; it may ulcerate and bleed, but pain and pruritus are uncommon. In the differential diagnoses of subungual tumors, glomus tumor, soft tissue chondroma, keratoacanthoma, hemangioma, lobular capillary hemangioma, epidermal and mucoid cysts, squamous cell carcinoma, and malignant melanoma have been suggested. But atypical fibroxanthoma has not been included in the differential diagnoses. We report a case that occurred in a 56-year-old man with subungual atypical fibroxanthoma mimicking malignant soft tissue tumor in the right fifth toe.