Gastric carcinoma metastatic to the bone marrow: immunoperoxidase identification of KMO-1 antigen in MGG-destained aspirate.

A case is presented that illustrates the application of the immunoperoxidase technique to the May-Grünwald-Giemsa (MGG)-destained bone marrow aspirate. The cytologic findings in a MGG-stained smear of the bone marrow suggested a metastatic epithelial tumor. Subsequently, a positive reaction to KMO-1, a monoclonal antibody raised against a colon carcinoma cell line, was demonstrated in tumor cells in the MGG-destained smear sample as well as in the paraffin-embedded section of the primary gastric cancer. The demonstration of the cancer-associated antigen in the MGG-destained material may be useful in establishing the diagnosis of metastatic tumor in the bone marrow.