A cardiac myxoma with interleukin-6 production and cerebral metastasis.

The occurrence of cerebral metastasis from cardiac myxoma is extremely rare. We present a 70-year-old man who had atrial myxoma with two metastatic myxomas in his brain. Histopathologic examination revealed a benign myxoma. An elevated interleukin-6 (IL-6) concentration in the serum, and immunohistochemical staining of the primary myxoma by an anti-IL-6 monoclonal antibody confirmed interleukin production by the myxoma. The IL-6-positive myxoma cells were closely attached to the cerebral endothelial cells. This suggests that IL-6 production by the atrial myxoma may have been an important factor for intravascular metastasis or embolization.