An unusual presentation of lymphoma

Abstract This case illustrates an unusual presentation of diffuse large B cell lymphoma (DLBCL) with florid central nervous system disease and an isolated right coronary artery lesion. Differentials included primary central nervous system lymphoma with IgG4-related disease of the right coronary artery, versus Stage IV DLBCL of the right coronary artery with CNS involvement. This case posed a diagnostic conundrum and challenged the choice of optimal treatment.