Delayed Uptake on 123I-IMP SPECT as a Diagnostic Clue in Cranial Vault Lymphoma in a 25-Year-Old Man: A Case Report.

Lymphoma involving the cranial vault is an extremely rare condition that is often difficult to diagnose preoperatively because its imaging findings mimic those of other skull tumors. We report a case of diffuse large B-cell lymphoma of the cranial vault in a 25-year-old man presenting with a rapidly enlarging frontal mass. Magnetic resonance imaging demonstrated marked diffusion-weighted hyperintensity, and 123I-IMP SPECT showed increased tracer uptake with further accumulation on delayed images. These findings raised suspicion of malignant lymphoma before surgery. Histopathological examination confirmed diffuse large B-cell lymphoma. This case suggests that 123I-IMP SPECT may provide useful adjunctive information for raising suspicion of lymphoma among cranial vault tumors and may contribute to improved preoperative diagnosis.