Floret Cells in Lipomatous Lesions of Orbit
HZ Amer, NM Mirani. UMDNJ-NJMS, Newark, NJ
Background: Lipomatous lesions of the orbit include pleomorphic lipoma (PL) and subconjunctival prolapsed fat (SPF). These lesions consist of mature fat and multinucleated giant cells with a floret-like pattern, which are CD34 +, S-100 -, and CD68 -. It has been reported that floret cells in SPF are an age related degenerative process. In this study we assess the presence of floret cells and dense collagen in orbital PL and SPF.
Design: We identified 18 lipomatous orbital lesions from 1990 to 2008. 8 were clinically called orbital mass and diagnosed as lipoma, however upon further inquiry were confirmed to be SPF. 10 were diagnosed as PL based on clinical and morphological ground. All 18 cases were assessed for the presence of floret cells and collagen. CD34, S-100, and CD68 was performed on 17 of 18 cases (1 case of SPF was excluded in absence of floret cells).
Results: In our study, both SPF and PL affected males more than females (14/18, 77%), non-whites more than whites (11/13, 84.6%), and mainly occurred over the age of 55 (14/18, 77%). The majority of lesions measured 1-2 cm (15/18, 83%). 7 of 8 SPF cases had infrequent floret cells (>15 in 2/7, 28.5%). 3 of 8 cases showed dense collagen. All floret cells stained for CD34.
All 10 cases of PL had numerous floret cells (>15 floret cells in 6/10, 60%), that stained for CD34, and dense collagen was seen in 8 of 10 cases. The mature adipocytes stained for S-100, and CD68 stained histiocytes.
|N||DENSE COLLAGEN||>15 FLORET CELLS|
Conclusions: In our study SPF and PL is mainly seen in non-white males over the age of 55, and measure 1-2 cm. Floret cells and dense collagen, features suggestive of PL, can also be seen in SPF, but are relatively less numerous. Floret cells and dense collagen are therefore not pathognomonic for PL but rather reflect a degenerative process. Floret cells of these lesions stain for CD34, and do not stain for CD68 or S-100.
Tuesday, March 10, 2009 9:30 AM
Poster Session III # 215, Tuesday Morning