Monoclonal antibodies in detection of choroidal melanoma

Three monoclonal antibodies (MoAbs) prepared against cutaneous melanomas were tested against one group of 12 choroidal melanomas with indirect immunofluorescence in frozen sections. A fourth MoAb was tested in paraffin sections of a second group of 47 choroidal melanomas. One MoAb (NKI-M7) did not react with choroidal melanoma, even though it had a high sensitivity for cutaneous melanoma. A second MoAb (NKI-M6) showed a positive reaction with only 2/12 choroidal melanomas. The third MoAb (NKI/beteb) reacted with all choroidal melanomas, regardless of the cell type. MoAb NKI/C-3 was positive with 38/47 (81%) choroidal melanomas. We conclude that NKI/C-3 and NKI/beteb have a high sensitivity for both cutaneous and choroidal melanomas in frozen sections. Of these two antibodies NKI/beteb was the most specific for cutaneous naevi and melanomas.