Computed tomography features of cerebral spread of malignant melanoma

The CT features of cerebral involvement by metastatic malignant melanoma are described in 28 patients. The most common locations of the primary lesion were the trunk and lower limbs. There was a high incidence of extracerebral metastasis at the time of diagnosis of cerebral involvement. Headache and behavioral changes were the most frequent presenting symptoms; 7% of patients with asymptomatic. The cerebral metastases were classified by size (< 1 cm, 1-4 cm, > 4 cm), with more than half measuring 1-4 cm. The larger lesions usually occurred singly. Peritumoral edema was detected in 89% of patients, hemorrhage in 19%, pressure signs on the ventricles in 37%, midline deviation in 15%, and leptomeningeal spread in 11%. No correlation was noted between size of tumor and other radiological features. Unilateral involvement was documented in 44% of cases. In the majority of patients the metastases were located at the periphery of the brain, mostly in the temporal and parietal lobes. Neuroimaging studies of the brain in asymptomatic patients with malignant melanoma may reveal occult metastases and influence the choice of treatment.