Introduction : Acinar cell carcinoma of pancreas is an uncommon malignant neoplasm that about 1-2% of pancreatic neoplasm. This case report is about acinar cell carcinoma of the pancreas with stomach and pericolic adipose tissue invasion.

Methods : A 73-year old man was visit the local clinic with a 2-month history of epigastric pain and 5kg weight loss for 1-month, Abdomen USG shown about 12cm pancreatic tail mass. The patient was admitted in our hospital. CT scans show that a huge, 12cm, solid and necrotic mass in the anterior aspect of the pancreas body tail, extending to the upper body posterior gastric serosal surface. EUS revealed the mass contained multiple cystic portion and compress the upper body to posterior wall of stomach. Colonoscopy was failed to pass the lesion because of narrowing lumen.

Results : Distal pancreatectomy, gastric wedge resection and colonic segmental resection were done. The pathological report showed acinar cell carcinoma, pancreatic tail to body with invasion to the stomach and pericolic adipose tissue, no involvement of spleen.

Conclusions : Adjuvant chemotherapy was done. The patient is wellbeing without any recurrence within two years after the operation.