Exclusive Cerebellar and Leptomeningeal Metastases from Early Gastric Cancer 14 Months after Proximal Gastrectomy: An Autopsy Case Report

We report a rare autopsy case in which the patient received gastrectomy after an endoscopic diagnosis of early gastric cancer, and had deteriorated due to exclusive metastatic cerebellar tumors identified 14 months after surgery. A 65-year-old male was diagnosed as having a 0-IIc-type early gastric cancer on the posterior wall of the upper stomach by gastrointestinal endoscopy in search of a cause of epigastralgia, and thus received proximal gastrectomy and pyloroplasty. Although the tumor was in the early stages and limited within the mucosal layer, adjuvant chemotherapy was started by using S-1 80 mg daily due to evidence of metastasis into lymph node #3 at the lesser curvature. Evidence of both recurrence and metastases was not detected by CT scans of the chest, abdomen, and pelvis, and the chemotherapy was completed 12 months after surgery. However, the patient was admitted to hospital 14 months postoperatively due to dizziness and gait disturbance. Cranial MRI (Magnetic Resonance Imaging) revealed multiple tumors in the bilateral cerebellar hemispheres with additional leptomeningeal involvement. The patient died 2 weeks after admission. An autopsy revealed metastatic cerebellar tumors and leptomeningeal lesions from the early gastric cancer, and obstructive hydrocephalus due to metastatic cerebellar tumors. To our knowledge, this case is the first report of metastasis exclusive to the cerebellum and leptomeninges from early gastric cancer limited to the mucosal layer.