[Clinicopathologic features, diagnosis and treatment with solid-pseudopapillary tumor of the pancreas: a report of 33 cases]. - Chun-hui Yuan; Dian-rong Xiu; Xue-ying Shi; Zhao-lai Ma; Zhi-fei Li; Ming Tao; Yi-mu Jia; Jing-Wei Xiong; Tong-lin Zhang (Zhonghua wai ke za zhi [Chinese journal of surgery], 2012)