[A case of mediastinal cancer of unknown primary with elevation of serum concentrations of interleukin-6].

Interleukin-6(IL-6)is an inflammatory cytokine. It's produced by monocyte, lymphocyte, vascular endothelial cell, and fibroblast. Elevation of serum concentrations of IL-6 is reported a lot of kind of diseases, such as cancer, infection, inflammatory diseases. But it is production mechanism was still unknown. A 67-year-old man was referred to our hospital because of treatment against the large mediastinal cancer of unknown primary. He had complication with superior vena cave syndrome. After he was exposed to irradiation, the tumor size was reduced, his symptoms were improved and the serum IL-6 level was decreased.