Atypical fibroxanthoma of the scalp following hair transplantation in a 35-year-old male

Surgical excision margins for fibrohistiocytic tumors, including atypical fibroxanthoma and undifferentiated pleomorphic sarcoma: A probability model based on a systematic review

BACKGROUND

Mohs micrographic surgery or wide local excision is the treatment of choice for fibrohistiocytic tumors with metastatic potential, including atypical fibroxanthoma (AFX) and cutaneous undifferentiated pleomorphic sarcoma (cUPS). Since margin clearance is the strongest predictor of clinical recurrence, improved recommendations for appropriate surgical margins help delineate uniform excision margins when intraoperative margin assessment is not available.

OBJECTIVE

To determine appropriate surgical wide local excision margins for AFX and cUPS.

METHODS

Literature search (Ovid MEDLINE, Embase, Web of Science, and Cochrane Library from inception to March 2020) to detect case-level data. Estimation of margins required using a mathematical model based on extracted cases without recurrences.

RESULTS

Probabilistic modeling based on 100 cases extracted from 37 studies showed peripheral clearance margin (ie, wide local excision margin) calculated to clear 95% of all tumors was 2 cm for AFX and 3 cm for cUPS. AFX tumors 1 cm or less required a margin of 1 cm.

LIMITATIONS

Data were extracted from published cases.

CONCLUSIONS

Atypical fibroxanthoma removed with at least a 2-cm peripheral excision margin is less likely to recur. Smaller tumors 1 cm or less can be treated with a more conservative margin. Margin-control surgical techniques are recommended to ensure complete removal while minimizing surgical morbidity.

Atypical fibroxanthoma--a retrospective immunohistochemical study of 42 cases

PURPOSE

Atypical fibroxanthoma is a cutaneous dermal malignancy that presents on the sun-damaged skin of elderly people. It requires a definitive diagnosis, from a high-grade sarcoma to a nonmesenchymal neoplasm. The recommended treatment protocol differs from similar histologically related tumors; thus, a diagnosis of atypical fibroxanthoma should fulfill strict histologic and immunohistochemical stain criteria. The use of these standards will exclude other skin malignancies, including malignant fibrous histiocytoma, angiosarcoma, malignant melanoma, and squamous cell carcinoma. This study was performed with the aim of identifying key immunostains to develop diagnostic criteria.

MATERIALS AND METHODS

Forty-two cases were studied retrospectively over a 10-year period using a panel of immunostains.

RESULTS

The average age at presentation was 78 years, with a male predominance. The scalp was found to be the most common site of occurrence, although other investigators have found the forehead, cheeks, nose, and ears as the prevailing sites of presentation.

CONCLUSIONS

An extensive panel of immunohistochemical stains can be used to prove a diagnosis of atypical fibroxanthoma.