An autopsy case of malignant lymphoma with a high serum CA 125 level occurring only in the brain and pericardium.

We report an autopsy case of a central nervous system (CNS) B-cell type lymphoma followed by cardiac tamponade. In this case, lymphoma cells which occurred primarily in the pericardium appear to metastasize to the brain and gradually increase in size in spite of control of the CNS lesion. The serum carbohydrate antigen 125 (CA 125) level was highly elevated and the autopsy findings showed the involvement of lymphoma only in the pericardium rather than the CNS, and the pericardium, not the tumor cells, was immunohistochemically positive for CA 125. Through this rare case, two things are suggested: first, the serum CA 125 level is elevated when B-cell type lymphoma infiltrates the coelomic epithelium; second, CA 125 is overproduced and secreted by the pericardium but not the lymphoma cells. Measurement of the serum CA 125 level may become a diagnostic marker for the infiltration of malignant lymphoma in the coelomic epithelium such as the pericardium, peritoneum or pleura.