Radical resection of T1 pancreatic adenocarcinoma with a pseudocyst of the tail due to acute obstructive pancreatitis: report of a case

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.