LAUSR

AFX: atypical fibroxanthoma dVIN: differentiated-type vulvar intraepithelial neoplasia UPS: undifferentiated pleomorphic sarcoma INTRODUCTION The term atypical fibroxanthoma (AFX) was first used in 1963 by Helwig et al to indicate a typically nodular ulcerative tumor arising on sun-exposed skin of the head and neck of the elderly. Furthermore, AFX has been described after radiation therapy and in immunosuppressed patients, specifically in transplant patients or in HIV-positive patients. A diagnosis of AFX requires most caution, because it implies a biologically benign lesion that must be differentiated from malignant cutaneous tumors. Here we underline the problems of differential diagnosis and therapeutic management of AFX in a previously unrecognized site, providing a description of its clinical and pathologic features, which could assist both the clinician and pathologist in avoiding misdiagnosis and relative unnecessary treatment.