This article is protected by copyright. All rights reserved. Background: Atypical fibroxanthoma (AFX) and pleomorphic dermal sarcoma (PDS) share clinical, pathological, immunohistochemical and molecular features, though PDS is associated with a more aggressive behavior. Methods: We revised 71 tumors fulfilling criteria for AFX and PDS to further stratify their biological potential. Results: Lesions predominate on the scalp of elderly men, were frequently ulcerated, one case presented necrosis, one vascular, and another perineural invasion. Fifty-one tumors were limited to reticular dermis (71.8%), 20 invaded subcutaneous tissue, focally in 13 cases (18.3%), and diffusely in seven (9.9%). A significant more frequent subcutaneous invasion was observed in tumors showing predominantly spindle compared to pleomorphic/mixed cell morphology (p= 0.02). At a follow-up of 17-125 months, 4 cases recurred locally, 4, 6, 10 and 13 months after surgery; no metastases were observed. Three tumors were composed of spindle cells, and one of clear cells. Three cases had margins focally involved, the fourth case had clear margins. Conclusion: Depth of invasion and state of margins are criteria predicting prognosis in AFX/PDS; in addition, spindle cell morphology seems to be related to a more infiltrative pattern of growth and consequently aggressiveness. Grouping these tumors on a morphologic base could contribute to clarify their different biological behavior.