A solitary brain metastasis from gastroesophageal junction adenocarcinoma 13 years after curative multimodality treatment: a case report and review of the literature

Abstract

Brain metastases in gastroesophageal adenocarcinoma are uncommon and can cause substantial neurological morbidity. Here, we report the case of a 58-year-old patient who developed a solitary brain metastasis thirteen years after curative-intent multimodality treatment for a Siewert type II gastroesophageal junction adenocarcinoma (GEJA). The intracranial lesion was initially radiologically suspected to be a primary brain tumour, while systemic restaging showed no extracranial disease. Histopathology, immunohistochemistry, clinical history, and methylome profiling supported metastatic recurrence from the prior GEJA. This case is noteworthy for the exceptionally long disease-free interval, the brain-only presentation after routine oncological surveillance had ended, and the diagnostic importance of tissue confirmation and integrated pathological assessment when a new intracranial lesion appears many years after curative treatment. This case supports maintaining late metastatic recurrence in the differential diagnosis of symptomatic brain lesions without implying a role for routine neuroimaging in asymptomatic long-term survivors.