T2-hyperintense, Non-Gadolinium-enhancing, Diffusion-Restricted Symmetrical Curvilinear Lesion of the Anterior Pons: a Rare Radiological Pattern of Leptomeningeal Metastatic Disease Secondary to Likely Lung Adenocarcinoma

Leptomeningeal carcinomatosis is a devastating sequelae of metastatic cancer. It has protean manifestations on imaging. An elderly woman presented to our tertiary centre with symptoms suggestive of a cerebrovascular accident. Investigations revealed no evidence of this. There was clinical, contextual and radiological evidence of an underlying neoplasm.Magnetic resonance imaging (MRI) demonstrated evidence of a rare morphology (anterolateral pontine leptomeningeal enhancement) in the presence of a probable concomitant lung adenocarcinoma. Other reports have previously described this same neuroradiology, seemingly always in association with lung adenocarcinoma.The purpose of this report is to highlight an unusual case and discuss its peculiarity and pathophysiology. Our patient is the latest documented of a small cohort with this constellation of clinical and neuroradiological features.This study demonstrates the importance of differential diagnosis in stroke medicine, specifically the need to consider neoplastic phenomena in patients admitted following putative cerebrovascular events.