A cerebral clue in the stomach: Brain lesion leads to discovery of hidden gastric cancer.

introduction and importanceBrain metastases from gastric adenocarcinoma are exceptionally rare, comprising only 0.1-0.16 % of all brain metastases. These cases present unique diagnostic challenges, particularly when neurological manifestations precede gastrointestinal symptoms. Understanding such atypical presentations is crucial for timely diagnosis and appropriate management. CASE PRESENTATION: An 82-year-old male presented with non-specific neurological symptoms including dizziness, fever, and seizures, without any reported symptoms of primary gastric involvement. Initial neuroimaging revealed a left frontal brain lesion, which upon biopsy was confirmed to be an undifferentiated carcinoma. Subsequent positron emission tomography-computed tomography identified a primary gastric tumor with evidence of systemic metastatic spread. CLINICAL DISCUSSION: The case highlights the diagnostic complexity of brain metastases from gastric cancer, particularly when presenting without primary site symptoms. A comprehensive multi-modality diagnostic approach, including neuroimaging, histopathological analysis, and molecular studies, was essential for establishing the definitive diagnosis. Treatment involved a coordinated multi-disciplinary strategy combining systemic chemotherapy (capecitabine and oxaliplatin) with targeted brain radiation therapy.

conclusionThis case emphasizes the importance of maintaining a broad differential diagnosis and considering rare metastatic patterns, even in clinically atypical scenarios lacking primary tumor symptoms. It also underscores the value of comprehensive diagnostic evaluation and multi-disciplinary collaboration in managing such complex oncological cases.