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.
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).
(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.
(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.