Multicenter study of serous cystic neoplasm of the Japan pancreas society

There have been only a few reports on follow-up results of serous cystic neoplasm (SCN) of the pancreas. The frequency of malignancy and surgical indication of SCN are not determined yet. In this multi-institutional study of the Japan Pancreas Society, a total of 172 patients with SCN were enrolled. The mean follow-up period was 4.5 years. Surgical resection was performed in 90 patients, whereas the remaining 82 were simply observed. Of all patients, 20% were symptomatic. The tumor was located in the pancreatic head (39%), body (35%), and tail (22%). The mean diameter of the tumor was 4.1 cm. None of the patients showed distant or lymph node metastasis except for liver metastasis found in 2 patients (1.2%). No patient died during the follow-up. The preoperative diagnosis did not correctly identify SCN in 57 (63%) of 90 resected cases. A honeycomb appearance, which is one of the most characteristic findings of SCN, could be diagnosed better by endoscopic ultrasonography than by other imaging diagnostic modalities. Surgical resection should be considered only when clear distinction from other surgical diseases is difficult, when symptoms or mass effects are present, and when the tumor size is large.