Caption: An
atypical fibroxanthoma, in a 94-yearold woman, who presented with a 1-month history of an asymptomatic, pink nodule on her left eyebrow: She had a history of nonmelanoma skin cancers on the face.
Atypical fibroxanthoma is a diagnosis of exclusion.
Morphologically and immunohistochemically, the features were consistent with
atypical fibroxanthoma. The closest resection margin was found to be 3 millimetres located superiorly.
Kossard, "Procollagen 1 expression in
atypical fibroxanthoma and other tumors," Journal of Cutaneous Pathology, vol.
Many secondary changes have been described in
atypical fibroxanthoma, such as keloidal areas, myxoid or chondroid changes, osteoclast-like giant cells, sclerosis, fibrosis, pigmentation, hyalinization, or hemorrhagic areas (1-3, 11-19).
Atypical fibroxanthoma (AFX) has been a topic for debate since the 1960s, when Helwig (1) coined its present name.
The differential diagnosis of atypical spindle cell neoplasms on sun-damaged skin includes
atypical fibroxanthoma (AFX), spindle cell or desmoplastic melanoma (see melanocytic neoplasms below), spindle cell SCC, and leiomyosarcoma.
Atypical fibroxanthoma (AFX) is a rare neoplasm that shows worrisome clinical and histologic features, but typically carries a good prognosis.
Recent studies showed that CD99 labeled 17 of 17 cases (100%) and 19 of 26 cases (73%) of
atypical fibroxanthoma, with most showing a moderate to strong staining pattern.
Cases with atypical cytologic characteristics may simulate
atypical fibroxanthoma, leiomyosarcoma, malignant peripheral nerve sheath tumors, other sarcomas, or sarcomatoid carcinomas.
Both squamous cell carcinoma and
atypical fibroxanthoma arise on sun-damaged skin.
It has also been demonstrated recently in the majority of xanthomatous skin lesions, (8)
atypical fibroxanthomas, typical dermatofibromas, and occasional epithelioid dermatofibromas.
