RESUMEN
Objective: To describe the CT and MR features of CNS lymphoma (both PCNSL and SLCNS groups) and to determine whether there is a difference. Methods: A retrospective study of CNS lymphoma in 100 patients at the department of Medicine, Siriraj Hospital, Mahidol University, during January 1997 – September 2002, for neuroimaging analysis. We retrospectively analyzed all available CT and MR findings of these patients by a neuroradiologist who was blinded to the patients’ clinical histories. The imaging studies were evaluated for density in CT, intensity in MR, pattern of enhancement, leptomeningeal enhancement, number of lesions, location and degree of edema. For MRI of spines, we additionally classified 4 menifestations: osseous lymphoma, spinal epidural lymphoma, lymphomatous meningitis and intramedullary lymphoma. Results: Only 33 CTs of the brain, 12 MRs of the brain and 11 MRs of spines were available for retrospective evaluation in this study. For CTs of the brain, most of the lesions showed hyperdensity on non-contrast CT (45% in PCNSL and 59% in SLCNS) with homogenous enhancement on contrast CT (78% in PCNSL and 75% in SLCNS). Eleven percent of ring enhancement lesions in PCNSL and eight percent in SLCNS were found in all patients with HIV infection. For MRs of the brain, most lesions of PCNSL and SLCNS showed hypo-isointensity in both T1W and T2W and homogenous enhancement. Locations of PCNSL were found in cerebral white matter and corpus callosum (55.5%) and basal ganglia (33.3%). SLCNS were found in cerebral white matter (50%), cavernous sinus (37.5%), basal ganglia (6.25%) and brainstems (6.25%). Conclusion: CNS lymphoma has been increased in Thailand. Imaging findings in PCNSL and SLCNS groups were not difference in this study. The pattern of imaging findings of CNS lymphoma in Thailand was similar to CNS lymphoma in the world.