Pathological differential diagnosis of solid-pseudopapillary neoplasm and endocrine tumors of the pancreas

AIM:To investigate differential points of solid-pseudo-papillary neoplasm (SPN) of the pancreas and pancre-atic endocrine tumor (PET).METHODS:Ten cases of SPN and fourteen cases of PET were studied in this retrospective study. Clinical and pathologic features,immunostaining reactions and β-catenin gene mutations were analyzed.RESULTS:The mean age of SPN patients was 25.6 years and these patients had no specific symptoms. The mean diameter of the tumors was 11.0 cm,9/10 cases were cystic or a mixture of solid and cystic structures,and there was hemorrhage and necrosis on the cut surface in 8/10 (80%) cases. Characteristic pseudo-papillary structure and discohesive appearance of the neoplastic cells were observed in all 10 (100%) cases. The results of immunostaining showed that nuclear expression of β-catenin and loss of E-cadherin in all the cases,was only seen in SPN. Molecular studies discov-ered that 9/10 (90%) cases harbored a point mutation of exon 3 in β-catenin gene. On the other hand,the mean age of PET patients was 43.1 years. Eight of 14 cases presented with symptoms caused by hypoglyce-mia,and the other 6 cases presented with symptoms similar to those of SPN. The mean size of the tumors was 2.9 cm,most of the tumors were solid,only 3/14 (21%) were a mixture of solid and cystic structures,and macroscopic hemorrhage and necrosis were much less common (3/14,21%). Histologically,tumor cells were arranged in trabecular,acinar or solid patterns and demonstrated no pseudopapillary structure and discohesive appearance in all 14 (100%) cases. The results of immunostaining and mutation detection were completely different with SPN that membrane and cytoplastic expression of β-catenin without loss of E-cadherin,as well as no mutation in β-catenin gene in all the cases. CONCLUSION:Both macroscopic and microscopic features of SPN are quite characteristic. It is not difficult to distinguish it from PET. If necessary,immunos-taining of β-catenin and E-cadherin is quite helpful to make the differential diagnosis.

Expressions of Livin and Smac and their correlation in endometriosis

Objective: To explore the expression of Livin (a new member of inhibitors of apoptosis proteins) and second mitochondria-derived activator of caspases (Smac) in endometriosis (EMs), and the relationship of Livin and Smac with menstrual cycle and clinical staging of EMs, as well as correlation analysis. Methods: 60 cases of patients, who were given laparoscopic surgery or laparotomy operation due to EMs (confirmed by post-operative pathological examinations) in Department of Obstetrics and Gynecology of the Third Affiliated Hospital of Inner Mongolia Medical College from October 2010 to April 2012, were selected and included into the study group. The study group was subdivided into the eutopic group and the ectopic group, each of which contained 30 cases (16 cases for the proliferative phase, 14 cases for the secretory phase). 30 samples of normal endometrial tissues were chosen as the control group. Immuno-histochemical method (SP) was used to determine the expression of Livin and Smac proteins in each group, with statistical analysis conducted to the results. Results: The expression of Livin in eutopic and ectopic endometrial tissues in EMs was significantly higher than that in normal endometrial tissues in the control group, and the difference was statistically significant (χ2 = 12.510, p < .05);The expression of Smac in eutopic and ectopic endometrial tissues in EMs was significantly lower than that in normal endometrial tissues in the control group, and the difference was statistically significant (χ2 = 19.530, p < .05). The expression of Livin and Smac in the eutopic and the ectopic endometrial tissues in EMs had no correlation to clinical staging (χ2 = 0.741 and χ2 = 0.002 respectively, all p > .05);In the eutopic and the ectopic endometrial tissues in EMs, the expression of Livin was negatively correlated to the expression of Smac (rs = -0.933 and rs = -0.867 respectively, all p < .05). Conclusions: The high expression of Livin and the low expression of Smac enhance the abilities of hyperplasia and anti-apoptosis of ectopic endometrial cells, which leads to the occurrence and development of EMs.