CT findings of solitary intracranial metastasis

The authors retrospectively reviewed and analyzed CT scans of fifity patients with solitary intracraniallesion selected from 118 patients who had been confirmed to have itracranial metastasis from 1979 to 1985. Theresults were as follows: 1. The most common primary tumors with solitary metastasis, in order of frequency, werelunch cancer(25), breast cancer(6), choriocarcinoma(5), colon cancer(5). lymphoma(2) and others(7). 2. Precontrastscans obtained in 35 cases showed cystic very low density in 20%, slightly low density in 9%, isodensity in 20%, high density in 51% when he densities of the lesions were compared with that of the normal brain tissue 3. Aftercontrast enhancement 43 out of 50 showed one of 4 patterns of enhancement. Homogeneous enhancement withoutnecrosis were found in 26%, homogeneous enhancement with necrosis in 18%, ring-enhancement in 26% and irregularenhancement in 16%. No enhancement was found in 14%. 4. The locations of hte metastatic lesions were intrassxialin 45 and extraaxial in 5. Among the intrassxial lesions, the parietal lobe was the most common location (22). Extrassxial metastases were epidural (3), calvarial(1) and leptomeningeal(1). 5. Degrees of surrounding edema weremild in 32%, moderate in 19% and severe in 49%.