Abstract
Purpose:
Ocular melanoma is the most common primary eye tumor observed in adults. It has been reported that conjunctival or ciliary body melanoma are associated with lymphatic metastasis due to the induction of lymphangiogenesis. However, the formation of lymphatic vessels in choroidal melanoma is a subject that has not well investigated. The purpose of this present study was to investigate if the discriminative expression of podoplanin (D2-40) is confirmed in choroidal melanoma in comparison to conjunctival melanoma.
Methods:
This study involved 22 patients (13 males and 9 females) with conjunctival melanoma (12 cases) or choroidal melanoma (10 cases). To visualize the podoplanin or macrophage, anti-podoplanin (D2-40) or anti-CD68 antibody was used. The area covered by a podoplanin-positive structure or CD68-positive cells was determined using National Institutes of Health (NIH) image software. Moreover, the number of podoplanin-positive vascular lumen was counted in both groups.
Results:
The number of podoplanin-positive vascular lumen was found to be significantly less in the cases with choroidal melanoma than in those with conjunctival melanoma (p=0.004). However, no difference of podoplanin or CD68 expression was found between conjunctival melanoma and choroidal melanoma. Moreover, no discriminative podoplanin or CD68 expression was found between the metastatic and non-metastatic groups.
Conclusions:
The findings of this study show that the number of podoplanin-positive lymphatic lumen, but not podoplanin expression, in choroidal melanoma was significantly less than in conjunctival melanoma. This data implicates that the formation of lymphatic lumen in melanoma might depend on the location of the tumor formation.
Keywords: 744 tumors •
554 immunohistochemistry •
453 choroid: neovascularization