We encountered a case of follicular lymphoma in a patient with high levels of serum CA125. On examination, abdominal lymph node swelling and hepatosplenomegaly were observed. The CA125 level decreased during treatment and was normalized at complete remission. An immunohistochemical assay of the lymphoma cells, however, failed to demonstrate any CA125. Several reports have described that CA125 might be produced by mesothelial cells in response to cytokines released by the lymphoma cells, and increased levels of CA125 have been significantly associated with abdominal involvement. It is possible that CA125 will become a useful marker in the observation of the progression of malignant lymphoma in the abdomen.
