Incidental Brain Stem Metastasis detected on Whole-Body PET/CT in a Known Case of Adenocarcinoma of the Esophagus: A Qualitative Comparative Case Report with CE-MRI

Abstract

Brain stem metastasis in esophagogastric cancer is relatively rare, with an overall incidence ranging from 1.6% to 5.1% across patient cohorts, and is generally associated with poor prognosis. The median overall survival of such patients ranges from 4 to 6 months. Brain stem metastasis in esophagogastric cancer subtypes can be detected on routine F-18-fluoro-deoxyglucose ( ¹⁸ F-FDG) positron emission tomography/computed tomography (PET/CT) imaging. Here, we present a case of a 52-year-old male, a known case of esophageal adenocarcinoma post six cycles of chemotherapy, with persisting complaints of dysphagia and nausea. The patient underwent a whole-body ¹⁸ F-FDG PET/CT scan after obtaining informed written consent for response assessment. The scan revealed FDG-avid thickening at the gastroesophageal junction and a low-grade FDG-avid, enhancing, space-occupying lesion in the brain stem involving the pons in the right paramedian location with mild perilesional edema. The efficacy was compared with contrast-enhanced magnetic resonance imaging (CE-MRI). This study highlights the potential role of whole-body PET/CT imaging in detecting rare sites of brain metastasis in esophagogastric subtypes noninvasively and with high efficacy in comparison to CE-MRI.