A 53-year-old male visited his primary physician for epigastric and
back pain. Abdominal-enhanced computed tomography (CT) revealed a simple
cyst of the pancreatic tail attached to the stomach. A distal main pancreatic duct (MPD) was clearly dilated, but no pancreatic
tumor was identified around the
stenosis of MPD by CT scan and magnetic resonance cholangiopancreatography (MRCP). Endoscopic retrograde pancreatography (ERP) revealed
stenosis and distal dilation of the MPD located between the body and tail of the pancreas. Endoscopic ultrasound (EUS) revealed a low density mass of 7 mm in size with distal dilation of the MPD. With the suspicion of a small
pancreatic cancer, the patient underwent distal
pancreatectomy and
splenectomy with
lymph node dissection (D2). On histopathological evaluation, a small pancreatic
adenocarcinoma of 6 mm in size was detected around the
stenosis of MPD. Final pathological diagnosis was moderately differentiated invasive ductal
adenocarcinoma of the pancreas with no
lymph node metastasis (Japan Pancreatic Society (JPS) classification 7th edition; Pbt, TS1 (6 mm), tub2, intermediate type, INF β, ly1, v1, ne1, mpd(-), pT1b, pN0, pM0, stage IA,PCM(-), DCM(-) and the Union International Control
Cancer (UICC) classification of malignant
tumors 6th edition; pT1, pN0, pM0, stage IA, R0). We herein reported a patient who underwent radical resection for T1 pancreatic
adenocarcinoma of 6 mm in diameter which caused
acute pancreatitis and a pseudocyst due to obstruction of the MPD.