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Atypical Fibroxanthoma: The Washington University Experience.

BACKGROUND
Atypical fibroxanthoma (AFX) is a rare dermal neoplasm typically occurring on sun-exposed skin in the elderly. As AFX remains a diagnosis of exclusion, updated characterization and treatment assessments are necessary to support informed diagnosis and management.


OBJECTIVE
Characterization of contemporary AFX and surgical outcomes by Mohs micrographic surgery (MMS) and conventional local excision (LE).


METHODS
Retrospective cohort analysis of all cases of AFX at our institution from January 2000 through July 2016.


RESULTS
Among 75 cases with median age at diagnosis 73 years, most occurred on the head and neck (68) independent of age. Most treated cases (42) underwent MMS alone, with median tissue removal greater for LE (2.6 cm, 4.5 cm) than MMS (0.6 cm, 1.2 cm). Over a median 26 months of follow-up, 6 recurrences were observed among 50 cases, with metastases in 2 cases. Intent-to-treat recurrence rates were 3.4% for MMS and 25% for LE. One nonrecurrent and 2 recurrent cases received revised diagnoses after initial treatment, yielding a true recurrence rate of 8.5%.


CONCLUSION
Despite diagnostic confounding by similar pathologies, surgical treatment of AFX remains effective. Tissue-sparing resection by MMS affords the potential for cosmetic and reconstructive advantage, without compromising recurrence compared with conventional excision.