Fibroxantoma atípico versus sarcoma pleomórfico dérmico

Atypical fibroxanthoma (FXA) is a little-known superficial mesenchymal tumor that generally occurs in photoex posed areas of older adults (1). It has an intermediate degree of malignancy due to its capacity for recurrence, and it is estimated that it comprises up to 0.2% of skin tumors (2). It has very similar histological features to undiffer entiated pleomorphic sarcoma, a high-grade, aggressive tumor with a poor prognosis. Subtle aspects, such as the clinical history and location of the lesion, are key to a more accurate diagnosis. The case report describes an elderly patient with a scalp lesion and diagnosis of “vascular malformation” without further clinical information, which made the diagnosis and differentiation between these two entities difficult,