Leptomeningeal carcinomatosis is a rare and devastating disease consisting of cerebral spinal fluid dissemination of malignancy with invasion into the meninges. While MR findings of meningeal carcinomatosis have been widely described, we report a new MRI pattern in a 56-year- old patient with lung adenocarcinoma, which consisted in extensive and symmetric lesions in the anterior parts of the cerebral peduncles and of the pons spreading toward the middle cerebellar peduncles.