Solid Pseudopapillary Tumor Of Pancreas:clinical And Immunohisto Chemical Features Of 26 Cases

Objective: To investigate the tissue origin, biological characteristics, pathological diagnosis criteria and prognostic factors of SPT. Methods:HE staining and immunohistochemical staining were carried out on the 26 cases of SPT specimens. Meanwhile we randomly selected 10 cases of normal pancreatic tissue surrounding the tumor, 10 cases of pancreatic neuroendocrine tumors and 10 cases of pancreatic cancer as a control group, and collected information of patients. Results: 26 cases on average age of 29.4 years.Two were male,the other were female,male to female ratio was 1:12 in this series. Among them 11 cases of nerve invasion or metastasis. 5 cases(19.2%) showed mild to moderate cellular atypia, 18 cases of hemorrhagic necrosis, 11 cases of mitotic figures. CD10 expressed in 23 cases;β-catenin expressed in 22 cases, as a nucleus or nuclear / cytoplasm abnormal immune response; α1- antitrypsin expressed in 22 cases; chromogranin A expressed in 7 cases; synaptophysin expressed in 10 cases; S-100 protein expressed in 2 cases; Nestin protein expressed in 12 cases; insulin receptor expressed in 3 cases; glucagon receptor expressed in 2 cases; pS2 protein expressed in 7 cases; PR expressed in 18 cases; ER expressed in 2 cases;Ki-67 expressed in 9 cases;PCNA expressed in 13 cases;E-cadherin did not expressed in membrane of all 26 cases, including 6 cases had abnormal plasma cells in the immune response. Conclusions:SPT cells were separated by wrapping around fibrovascular arranged to form multiple layers of false papillae, which was of important diagnostic value. We can use α1-antitrypsin CD10, PR and β-catenin as pathological indicators of this tumor. Suggesting that the tumor has infiltrated the invasion and metastasis of malignant features such as E-cadherin and β-catenin expression in the SPT. We found no correlation between the cellular atypia, hemorrhage and necrosis, Ki-67 proliferation index and PCNA expression and invasion, metastasis and recurrence. Progesterone receptor expressed in SPT, suggesting that the development of SPT had something to do with sex hormones.