[Antigen pattern in choroid melanoma in correlation with immunoscintigraphy]

Abstract

We have reported that the sensitivity of immunoscintigraphy in ocular melanoma is fairly low in comparison with (metastasizing) cutaneous melanoma. No significant correlation was found between the histological data for ocular melanoma and the immunoscintigraphic results. We therefore wanted to see whether we could demonstrate an antigen pattern that was different from that of cutaneous melanoma, which might explain our previous results. Our study comprised tumor tissue from 20 patients with ocular melanoma who had undergone previous immunoscintigraphic examination. Using immunohistochemical techniques, tumor immunoreactivity was investigated against 225.28S, the antibody used for immunoscintigraphy, on cryosections in 12 cases, and against anti-HMB-45, and anti-S-100 and anti-vimentin on paraffin sections in all 20 patients. In summary, there was marked immunohistochemical heterogeneity, and none of the antibodies examined showed a significant correlation with immunoscintigraphy. Even 225.28S that was used for the immunoscintigraphic examination did not retrospectively allow a predictable immunoscintigraphic outcome. When comparing our results with the literature on cutaneous melanoma we were also able to confirm differences in immunoreactivity with regard to the other antibodies. We conclude that the comparatively poor results in ocular immunoscintigraphy obtained with 225.28S are due to antigenic differences between ocular and cutaneous melanoma.