Gd-DTPA enhancement of cranial nerves on MR imaging. Neoplastic lesions

This study describes a radiological finding - enhancement of cranial nerves and correlates patients' clinical findings and outcome. Seven patients with enhancement of cranial nerves on postcontrast MR were retrospectively reviewed. Cranial nerves having contrast enhancement were optic, oculomotor, trigeminal, facial, acoustic, glossopharyngeal, vagus and accessory nerves. The patients' underlying diseases were malignant lymphoma (3), leukemia (1 patient) and metastatic tumor (2 lung, 1 rectum cancer). Most of the cases (4 out of 7) developed parenchymatous lesion later. Seven patients had CSF cytology study, positive in 3 cases, negative in 4 cases at first spinal tap. In 1 case (case 5) of negative cytology, elevated CEA (carcinogen antibody) was noted. In 2 cases, initial symptoms were sudden hearing loss. Autopsy was done for 1 case of metastatic tumor involving cranial nerves. Contrast MR is a useful examination for depicting cranial nerve involvement with neoplastic change.