Minute pancreatic carcinoma with initial symptom of acute pancreatitis

We experienced a case of minute pancreatic carcinoma in a 59‐year‐old man who complained of upper abdominal pain after drinking alcohol. Abdominal ultrasonography (US) revealed dilatation of the main pancreatic duct (MPD). Abdominal computed tomography (CT) and magnetic resonance cholangiopancreatography (MRCP) showed slight dilatation of the MPD and its obstruction near the portal vein. Endoscopic retrograde cholangiopancreatography (ERCP) demonstrated occlusion of the MPD, and cytology of aspirated pancreatic juice was negative for malignancy. With the diagnosis of benign localized obstruction of the MPD, the patient underwent surgery. There was a clear demarcation of hardness and color of the pancreas on the left margin of the superior mesenteric vein, and the caudal pancreas was hard and fibrotic. Intraoperative US revealed slight dilatation of the MPD, and the aspiration cytology result was class IV. First, segmental resection of the pancreas was performed, but pathological examination of frozen section showed neither malignancy nor stenotic lesion. An additional small portion of the proximal pancreas was resected. The specimen included a ductal carcinoma, 5mm in diameter. Accordingly, a pylorus‐preserving pancreatoduodenectomy was performed. Microscopically, the minute carcinoma had already penetrated the duct wall and infiltrated lymph vessels and veins. The patient has been under close observation at our outpatient clinic, and so far there have been no signs of recurrence. To improve the poor prognosis of pancreatic cancer, we should be alert to the occurrence of acute pancreatitis as an initial symptom.