A monoclonal antibody useful for the differential diagnosis between malignant lymphoma and nonhematopoietic neoplasms.

A monoclonal antibody designated as T29/33, which recognizes a major cell surface glycoprotein of hematopoietic cells, was tested as a possible tool to distinguish lymphoma from nonhematopoietic tumors having a similar morphologic appearance by light microscopy. Each of the 40 lymphomas studied by immunofluorescence and/or immunoperoxidase on frozen sections revealed the presence of the corresponding antigen, whereas 110 control tumors of various nonhematopoietic origins were negative. It was concluded that the T29/33 antibody may be of value in resolving the diagnostic problems presented by tumors in which the differential diagnosis is between non-Hodgkin's lymphoma and nonlymphoid tumors.