FLOW CYTOMETRIC ANALYSIS OF CELLULARY DNA CONTENT IN SYNOVIAL SARCOMA AND CLINICOPATHOLOGICAL CORRELATION

Synovial sarcoma is a distinct tumor with uncertain histogenesis and unpredictable prognosis. Flow cytometric DNA analysis which is being investigated for its prognostic significance in various tumors in the last ten years, has found limited application in soft tissue tumors as well. In this work, we aimed to investigate the correlation between the DNA content and proliferative activity of the synovial sarcomas and clinicopathologic characteristics. To the 22 synovial sarcoma cases examined in our pathology department flow cytometric analysis was applied. Of these cases 14 (60.9%) had aneuploid, 9 (39.1 %) had diploid DNA content. In tumors with aneuploidy average S phase fraction was high (12.23%), in diploid tumors was low (5.61%) (P<0.01). In cases with high mitotic activity the average S phase fraction was 11.29%, in cases with low mitotic activity it was 6.96% (P=0.05). High grade nuclear atypia was found in 54% of aneuploid tumors, was not present in diploid tumors. Low mast cell counts were observed in 66% of the cases with aneuploid DNA content, which is an indication of bad prognosis. Cellularity, histological subtype, secondary changes do not affect the aneuploidy or diploidy of the tumor. In this preliminary study with limited number of cases with follow-up, some indications have been observed that in synovial sarcoma some prognostic hints could be obtained with DNA analyses.

Keywords: Synovial sarcoma-flow cytometry-dna analysis