Radiological features of primary central nervous system lymphoma

Radiological features of 12 cases of primary malignant lymphoma of the central nervous system with histological confirmation were reviewed. Ten patients had primary intracranial lymphoma, and two spinal. Angiography yielded no specific findings. CT appearances varied widely. Any positive relationships were not found between histologic types of tumors and patterns of contrast enhancement in the present cases as well as in those reported previously. Gd-DTPA was used in two patients. All lymphomas showed low to isointensity signals on T1-WI and high signal intensities on rho-WI and T2-WI. Although MRI gave no additional informations to those on CT with regard to the differential diagnosis, it proved to be a very accurate, non-invasive method of providing better delineation of tumor on multiplanar basis. Use of Gd-DTPA improved quality of T1-WI by markedly enhancing the tumor. It is generally difficult to distinguish primary from secondary spinal lymphoma, but two spinal epidural lymphomas in the present series were considered primary, as we could detect no other lesion elsewhere in the body. We expect that MR imaging would lead to an improvement in the detection of lesion in the paravertebral area.