Fırat TATLIDIL, Seda GÜN
Annals of Clinical and Analytical Medicine - 2026;17(6):588-593
Aim: Kaposi sarcoma (KS) is a vascular neoplasm associated with human herpesvirus 8 (HHV-8). While conventional endothelial markers, such as CD31 and CD34, are well-established, the expression patterns of lymphatic markers (D2-40, Prox1) and the transcription factor FLI-1 across histological stages remain underexplored. Methods: Archival tissue from 80 HIV-negative KS patients was retrospectively analyzed. Lesions were staged as patch (n = 10), plaque (n = 25), or nodular (n = 45). Immunohistochemical staining for CD31, CD34, D2-40, FLI-1, Prox1, and HHV-8 was performed, with semi-quantitative assessment of staining extent (focal/diffuse) and intensity (weak/strong). Chi-square tests compared patterns across stages and markers (p<0.05). Results: All markers showed high sensitivity (95-100%). Staining extent and intensity were independent of stage for most markers (p>0.05), except D2-40 intensity, which increased significantly with progression (p=0.008). Nodular stage revealed significant discordances, where Prox1 extent was more frequently focal compared to the diffuse staining of HHV-8, CD31, D2-40, and FLI-1 (p<0.05). Conclusion: D2-40, Prox1, and FLI-1 are reliable diagnostic adjuncts, with D2-40 intensity correlating with advanced stages, suggesting a role in progression. These findings refine KS phenotyping and highlight potential pathogenic insights.
