[1105] Clinicopathologic Analysis of Ovarian Clear Cell Carcinoma: Comparison of Cases with and without Adenofibromatous Components and Implications for Pathogenesis

C Zhao, R Barner, R Kurman, M Stamatakos, R Vang. Magee-Womens Hospital of UPMC, Pittsburgh, PA; Armed Forces Institute of Pathology, Washington, DC; Johns Hopkins Hospital, Baltimore, MD

Background: Ovarian clear cell carcinomas (OCCC) with an adenofibromatous (AF) background (CCC w/ AF) have been shown to have some clinicopathologic differences compared with CCC without AF components (CCC w/o AF). The purpose of this study was to assess the clinicopathologic similarities and differences in a large number of these 2 types of CCCs and determine whether there is evidence for 2 different lines of pathogenesis.
Design: OCCC from the AFIP were re-reviewed. 427 OCCC were included and subdivided into CCC w/ AF (n=141) and CCC w/o AF (n=286). CCC w/ AF included cases with a cytologically benign and/or malignant AF components. Cases were assessed for various clincopathologic features.
Results: CCC w/ AF more frequently had pure tubulocystic architectural patterns (27% vs. 7%, p<.001). CCC w/o AF more frequently had a predominantly cystic gross appearance (42% vs. 21%, p<.001), advanced stage disease (43% vs. 21% stage >I, p <0.001), destructive patterns of stromal invasion (94% vs. 39%, p<.001), pure solid architectural patterns (15% vs. 1%, p<.001), higher grade (43% vs. 14% grade 3, p<.001), and non-CCC carcinoma component (10% vs. 4%, p=.04). The frequency of endometriosis (E-osis) in the ipsilateral ovarian tumor in CCC w/ AF (11%) was lower than in CCC w/o AF (20%, p=.03), but the difference between both tumors for the frequency of E-osis in the contralateral normal ovary or in extra-ovarian sites (15% vs. 20%, respectively) was not significant. Both tumor groups showed no differences in patient age, tumor size, bilaterality, presence of tumor on the ovarian surface, and other histologic architectural patterns.
Conclusions: OCCC w/ AF and OCCC w/o AF have certain differences in their clinicopathologic profiles. CCC w/o AF exhibit features that generally correlate with more aggressive behavior, such as higher stage. The fact that E-osis was associated with a subset of CCC w/ AF and that the frequency of E-osis in CCC w/o AF was similar suggest that AF- and E-osis-associated pathways of pathogenesis of CCC are not independent of one another. Given the higher grade, higher stage, and more frequent destructive patterns of stromal invasion in CCC w/o AF, some CCC w/o AF may represent tumor progression of CCC w/ AF in which the AF component has been overgrown. This should be taken into consideration for future pathogenesis studies of CCC.
Category: Gynecologic

Monday, March 9, 2009 2:15 PM

Platform Session: Section C, Monday Afternoon