[471] Atypical Fibroxanthoma (AFX): Clinicopathologic Characteristics and Natural History in a Large Single-Institution Series

TW McCardle, JS Zager, M Bui, S Shah, A Patel, VK Sondak, JL Messina. H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL; University of South Florida College of Medicine, Tampa, FL

Background: AFX is a cutaneous sarcoma of probable fibrohistiocytic origin related to pleomorphic sarcoma (malignant fibrous histiocytoma). The typical presentation is a rapidly growing nodule on sun-exposed skin of the elderly, & complete excision is considered curative in most cases. While its behavior is generally low-grade, there is controversy regarding diagnostic criteria, optimal surgical tx, adjuvant tx, & the natural history of the dz. We herein present a large single-institution series of AFX, including clinicopathologic characteristics & outcomes, stratified by tx type.
Design: An IRB-approved, retrospective review of the electronic medical record, pathology database, & cancer registry was performed on all pts dx'ed w/ AFX & tx'ed at our institution from (1990-2008). Demographics, tumor size, location, immunostains used, surgery type including excision size & margins, adjuvant tx, & outcomes were compiled.
Results: 47 pts w/ AFX were analyzed, 34 M & 13 F. Median age 74.0 yrs(38-92). Locations included: H&N(40), extremities(4), & trunk(3). Median tumor size was 1.8 cm(0.2-6.0 cm). Vimentin was positive in 16/17(94.1%), CD68 in 24/26(92.3%) & CD10 in 7/7(100%) cases. W/a median f/u interval of 13.5 mos., 8 (17%) pts recurred w/a median time to recurrence of 33.4 mos. 40 pts were tx'ed w/ wide excision (WE), 4 pts w/ Mohs surgery, 1 pt w/ Mohs & WE, 1 pt w/ radiotherapy (XRT); 1 pt had no further tx. Median width of excision was 3.2cm(0.67.0cm), w/ a median margin of excision of 1.6cm. 39 pts had negative margins; 7(17.9%) pts were tx'ed w/ XRT, of these 1(14.3%) recurred. 6/39(15.4%) pts w/ negative margins & no XRT recurred. 8 pts had positive margins; 2 received XRT & did not recur. 6 received no further tx, & 2(33%) recurred. Irrespective of margin status, 1/9(11.1%) pts tx'ed w/ XRT recurred, while 7/38(18.4%) pts not receiving XRT recurred. 9(19%) pts died w/ a median time to death of 36 mo's; 1 of these was confirmed to be due to AFX. One case had metastatic dz.
Conclusions: AFX occurs in elderly individuals, predominantly on the H&N. Pts w/ positive margins recurred more often compared to negative surgical margins. However, the risk is reduced w/ XRT. A subpopulation of recurrent tumors may behave in a more aggressive fashion. The mortality rate is low in AFX, but this biased due to its elderly population.
Category: Dermatopathology

Tuesday, March 10, 2009 1:00 PM

Poster Session IV # 61, Tuesday Afternoon