Objectives: 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.
Methods: 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.
Results: 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.
Conclusions: 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.