[Atypical fibroxanthoma. Clinical/pathological study of 10 cases].

INTRODUCTION: Atypical fibroxanthoma (AFX) is a rare tumor of unknown histogenesis, considered by most authorities as a superficial form of malignant fibrous histiocytoma (MFH). The aim of this work is to report the clinicopathological features of 10 cases of AFX. MATERIAL AND METHODS: Data were retrospectively collected of the computerized medical history. Clinical (age, onset-diagnosis time, location, accompanying pathology, outcome), histological (architectural pattern, cell type, ulceration, vascular or perineural invasion, subcutis involvement, pleomorphism, mitosis, inflammatory infiltrate) and immunohistochemical variable were analyzed. CASES REPORT: Clinical and epidemiological features coincide with those previously reported: onset late in life, short time onset-diagnosis, involvement of skin with notable sun damage and a good outcome. Pathologically all the cases showed a spindle-cell prevalence arranged in a vaguely storiform pattern, along with both, multinucleated and eosinophilic cells. DISCUSSION: The diagnosis of AXF is always of exclusion. Other spindle-cell tumors such as squamous cell carcinoma, malignant melanoma, leyomiosarcoma or dermatofibrosarcoma protuberans must be ruled out by immunohistochemical techniques. In spite of its rarity, the recognition of AFX is important in order to avoid inappropriately aggressive treatment.