Atypical fibroxanthoma (AFX) is an uncommon cutaneous neoplasm of pleomorphic myofibroblast-like cells. Diagnosis requires exclusion of other undifferentiated spindle and pleomorphic cell neoplasms by immunohistochemistry. We report two patients with p63-non-reactive spindle cell neoplasms which resembled AFX but demonstrated anomalous dot-like immunolabeling with antibodies to high molecular weight keratin and keratin 5. One case recurred locally, suggesting such lesions may behave aggressively. Whether these lesions represent keratin-positive dermal sarcomas or poorly differentiated carcinomas is debatable. Regardless of exact classification, our experience suggests such cases should be managed as high-risk non-melanoma skin cancers.
- atypical fibroxanthoma
- dot-like keratin
- squamous cell carcinoma
ASJC Scopus subject areas
- Pathology and Forensic Medicine