A 77-year-old man was admitted because of high fever and general malaise. Whole-body CT showed large bilateral adrenal masses and para-aortic lymphadenopathy. Needle biopsy of the adrenal mass revealed mononuclear tumor cells within the lumens of small vessels, indicating the features of angioendothelial lymphoma. Immunohistochemically, these tumor cells were B cell lineage (positive for LCA, Mx-pan B, MB-1, and negative for factor VIII-related antigen, UEA-1, QB/ENDO 10). We used a modified CHOP therapy (500 mg of cyclophosphamide, 40mg of 4'-o-tetrahydropyranyl doxorubicin, 2mg of vindesine, and 50 mg of prednisolone) due to the patient's advanced age and general condition. Following the first course of this modified CHOP, the adrenal masses and para-aortic lymph nodes decreased dramatically in size, and his subjective symptoms also improved remarkably. Following three courses of modified CHOP, the patient developed dementia and disturbance of consciousness. Brain MRI revealed enhanced multiple nodular lesions. A diagnosis of multiple brain metastasis was made and modified CHOP and radiation therapy were begun, which relieved his symptoms for some time. However, he later died of pneumonia with severe leukopenia. A postmortem examination was performed. Microscopic examination showed no residual tumor cells in the adrenal gland. brain lymph nodes, or other organs. These results suggest that modified CHOP and radiation therapy may have beneficial anti-tumor effects against angioendothelial lymphoma.