ABSTRACT
In this study, 25 conjunctival naevi and 25 conjunctival and choroidal melanomas were retrospectively collected and subjected to immunohistochemical staining using monoclonal antibodies S- 100 protein and HMB-45 using biotin streptavidin amplified system. Also, a quantitative DNA analysis was performed using Feulgen stain and measured by the CAS 200D image analyzer. Studied cases included 17 benign naevi, 8 dysplastic naevi and 25 malignant melanomas. S-100 protein and HMB-45 were highly sensitive markers to identify malignant melanoma of conjunctiva [sensitivity 100% for both]. Conjunctival naevi were 100% protein, while only four cases of dysplastic melanocytic naevi [DMN] were positive for HMB-45 [50% of DMN]. Aneuploidy was detected in 22 cases of malignant melanomas and only nine cases, eight DMN and one compound naevus [CN], showed aneuploid DNA distribution pattern and four of them were positive for HMB-45 and all for S-100 protein