[1197] Immunohistochemistry of Nodular Fasciitis of the Head and Neck.

Eric K Morgen, Paul Carter, Ilan Weinreb, Ayman Al-Habeeb, Danny MD Ghazarian. University Health Network, Toronto, ON, Canada; University of Toronto, ON, Canada

Background: Nodular fasciitis (NF) is a reactive soft-tissue lesion that usually presents in the trunk and extremities but has also been described in the head and neck. Accurate diagnosis of NF is important to exclude malignancy, and is often possible based on age, body-site, clinical presentation, histology, and immunohistochemistry (clasically vimentin+, SMA+, MSA+, S100-, desmin-). However, some cases remain difficult to distinguish from malignant lesions such as leiomyosarcoma, DFSP, low-grade myofibroblastic sarcoma, and Evans tumour, and a better characterization of NF protein expression could be helpful. To our knowledge, the published literature contains few cases evaluated for calponin (28/28 in one series), CD10 (1/3 in one series), and CD34 (0/10 in two series), and none for PGP 9.5, factor XIIIa, and CD56. This pilot study aims to investigate these less-well-characterized markers in NF of the head and neck.
Design: We searched the hospital database for cases diagnosed as NF from 1992 to 2010 and selected those originating in the head and neck. Original slides for these cases were reviewed, appropriate paraffin blocks were selected, and 7-micron sections were cut onto charged glass slides. Sections were stained for SMA, calponin, CD10, CD34, PGP 9.5, Factor XIIIa, and CD56. The presence (and compartment) or absence of staining was recorded.
Results: Six cases of NF fit our criteria. All were diagnosed by pathologists in subspecialty practice. Immunoreactivity is described in table 1.

Table 1. Immunohistochemistry Results
AntigenCases Staining PositiveCompartment
SMA6 of 6cytoplasmic
calponin6 of 6nuclear
CD106 of 6cytoplasmic and membranous
PGP 9.56 of 6nuclear and cytoplasmic
Factor XIIIa3 of 6nuclear and cytoplasmic
CD340 of 6 
CD560 of 6 

Conclusions: Based on this series of head and neck NF cases, SMA, calponin, CD10, and PGP 9.5 are consistently positive, Factor XIIIa is equivocal, and CD34 and CD56 are negative. These results confirm a well-established consensus for SMA, support initial findings for calponin and CD34, diverge from a previous result for CD10, and represent newly-reported findings for PGP 9.5, Factor XIIIa, and CD56. This immunoprofile sheds little new light on the histogenesis of NF. However, we propose that immunoreactivity for SMA, calponin, CD10, and PGP 9.5, combined with the traditional clinical and histologic features of NF, will be helpful in distinguishing NF from its mimicks.
Category: Head & Neck

Wednesday, March 2, 2011 9:30 AM

Poster Session V # 141, Wednesday Morning


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