Expression of a melanoma-tumor-associated antigen as demonstrated by a monoclonal antibody (D6.1) in cytopathologic preparations of human tumor cells from effusions and needle aspirates.

Immunocytopathologic studies were performed on 79 fine needle aspiration biopsies (FNABs) and effusions from 13 melanomas and 57 other human neoplasms with the monoclonal antibody (MAb) D6.1 raised against a partially purified melanoma-tumor-associated antigen (MTAA). The purposes of these studies were (1) to evaluate the ability of MAb 6.1 to react with melanoma cells in cytopathologic preparations and (2) to define the spectrum of reactivity of MAb D6.1 in cytopathologic preparations of non-melanomas. Cytocentrifuge preparations of the cytopathologic specimens were permitted to react with the primary antibody and were then stained by the avidin-biotin-immunoperoxidase method. Thirteen of 13 FNABs of malignant melanomas exhibited staining reactivity with MAb D6.1. Among the nonmelanoma tumors tested, staining reactivity was observed in 30 of 57 specimens. Among specific neoplasms, staining was present in 5 of 11 adenocarcinomas of the breast, 2 of 7 ovarian adenocarcinomas and 5 of 6 metastatic adenocarcinomas from the colon. Among 17 lung cancers examined, staining was noted in 4 of 7 adenocarcinomas, 3 of 4 large-cell undifferentiated carcinomas and 2 of 3 poorly differentiated squamous-cell carcinomas. Two small-cell undifferentiated carcinomas and one carcinoid failed to stain. Three of three adenocarcinomas of the pancreas showed staining. Among the remaining neoplasms examined, one specimen each of carcinoma of the prostate and the cervix and one carcinoma of undetermined primary exhibited staining. Two malignant lymphomas did not stain. Staining of mesothelial cells was observed in three of nine benign effusions.(ABSTRACT TRUNCATED AT 250 WORDS)