Intraocular Tumor-Associated Lymphangiogenesis: A Novel Prognostic Factor for Ciliary Body Melanomas With Extraocular Extension

Abstract

Purpose: : To evaluate whether intraocular tumor-associated lymphangiogenesis contributes to prognosis of ciliary body melanomas with extraocular extension and to study its association with other tumor characteristics.

Methods: : Twenty consecutive patients enucleated for a malignant melanoma of the ciliary body with extraocular extension were followed-up retrospectively. Lymphatic vessels were identified using LYVE-1 and podoplanin as specific immunohistochemical markers for lymphatic vascular endothelium. Kaplan-Meier and Cox regression analyses of melanoma-specific survival were performed.

Results: : Intraocular LYVE-1-positive and podoplanin-positive lymphatic vessels could be detected in twelve (60%) of the twenty ciliary body melanomas with extraocular extension. A higher number of lymphatic vessels was associated with larger tumor size (p=0.009), presence of epithelioid cells (p=0.030), heavy pigmentation (p=0.021), presence of vascular networks (p=0.045), and high microvascular density (p=0.001). Melanoma-specific mortality rates increased significantly with the presence of intraocular LYVE-1-positive and podoplanin-positive lymphatic vessels (p=0.008). A hazard ratio of 6.75 indicated the presence of lymphatic vessels as a strong prognostic factor (p=0.020).

Keywords: tumors • melanoma • oncology