Atypical fibroxanthoma†.

Atypical fibroxanthoma (AFX) is a rare skin neoplasm of low-grade malignancy and fibroblastic origin. AFX is a curable cutaneous disease and the diagnosis depends on knowledge of its clinical and histological features and combined immunohistochemistry markers. This study presents a case of a male patient, aged 90 years, presented with painless skin lesion in his ear. The lesion had been growing progressively for 2 months, measured ∼1.5 cm, ulcerated, fixed and firm. After a biopsy, the patient underwent a complete resection with adequate surgical margins and showed favorable evolution without complications or recurrence. The histopathological evaluation showed a poorly circumscribed ulcerated dermal nodule, mesenchymal proliferation, with pleomorphic spindle cells. There was infiltration of the deep dermis and subcutis, showing malignant features, but there was no invasion of cartilage. The immunohistochemical analysis confirmed the diagnosis of AFX.