A 56-year-old Japanese man developed a cerebral hemorrhage and was diagnosed with plasma cell-type multicentric Castleman's disease (MCD) based on the findings of an inguinal lymph node biopsy in addition to clinical findings, including hypergammaglobulinemia, anemia and elevation of the levels of CRP and serum IL-6. Although a renal biopsy showed nephrosclerosis, the levels of serum lipids and apolipoprotein were low. Following the initiation of treatment with anti-interleukin-6 receptor antibodies, the hypergammaglobulinemia, anemia, CRP level and serum lipid profile improved. However, inflammation due to overproduction of IL-6 persisted, and atherosclerotic vascular events occurred as critical complications, even though the serum levels of lipids were very low.