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

Abstract

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.

Keywords: early gastric cancer; exclusive brain metastases; leptomeningeal metastases; lymphogenous pathway; metastatic cerebellar tumor.

Fig. 1

A 0-IIc-type early gastric cancer on the posterior wall of the upper stomach (endoscopical findings; A, arrow, and Specimen; B, arrow) limited to the mucosal layer without lymphovascular invasion (C, hematoxylin–eosin stain, original magnification 12.5×, scale bar was 2 mm). Tumor mainly consisted of poor differentiated adenocarcinoma and signet-ring cell carcinoma (D, hematoxylin–eosin stain, original magnification 200×, scale bar was 100 μm). Tumor cells are positive for both CK 7 and CK 20.

Fig. 2

Cranial MRI revealed multiple nodules involving the bilateral cerebellar hemispheres, which were hypointense on T₁WI (A), hyperintense on T₂WI (B), and the tumors showed enhancement on gadolinium-enhanced T₁WI with leptomeningeal metastases through the cerebellar folia (C).

Fig. 3

Numerous nodules measuring 15–30 mm were located in the cerebellar hemisphere (A, arrow head), and compressed aqueduct and fourth ventricle (A, arrow). Microscopic finding revealed that the tumor mainly consisted of poor differentiated adenocarcinoma (B, hematoxylin–eosin stain, original magnification 200×, scale bar was 100 μm). There were leptomeningeal metastases that adenocarcinoma cells were scattered in the subarachnoid space through the medulla oblongata to the whole cerebrum, and were abundant around the cerebellum (C, hematoxylin–eosin stain, original magnification 200×, scale bar was 100 μm).