Primary CNS lymphoma associated with streptococcal abscess: an autopsy case

This report describes a case of streptococcal abscess in the nodules of a primary central nervous system (CNS) lymphoma. Magnetic resonance imaging (MRI) of the brain revealed multiple lesions with ringlike enhancement over the bilateral frontal, right temporal, and left parietal lobes. On admission, acute brain edema occurred following angiography, which resulted in respiratory arrest. Autopsy findings showed that the ringlike enhanced lesions on MRI were streptococcal abscesses localized in the lymphoma nodules. The lymphoma was classified as non-Hodgkin, diffuse large cells of B-cell lineage. No other lymphoma mass was found extracranially. An immunohistochemical study showed that the lymphoma cells were positive for leukocyte common antigen, Epstein-Barr virus, bax, and bcl-XL, and negative for L-26 and bcl-2. This case demonstrated that an opportunistic streptococcal abscess developed in primary CNS lymphoma in a patient without acquired immunodeficiency syndrome (AIDS), though a few similar cases have been reported in patients with AIDS.