Secondary malignant lymphoma of the central nervous system with delayed high uptake on 123I-IMP single-photon emission computerized tomography. Case report.

A case of secondary central nervous system (CNS) lymphoma with high uptake in the delayed image of N-isopropyl-[123I]-p-iodoamphetamine (125I-IMP) single-photon emission computerized tomography (SPECT) is presented. Previous to this report, only six cases of brain tumor with high uptake on the delayed 123I-IMP SPECT scan have been reported, two of which were CNS malignant lymphomas. Of 19 brain tumors examined with 123I-IMP SPECT at Kameda General Hospital, this case was the only one that showed high uptake in the delayed image. These data imply that 123I-IMP SPECT, which has now become rather obsolete as a tumor-imaging method, can be useful in diagnosing CNS malignant lymphoma.