Objective:To analyze the clinicopathological characteristics of atypical teratoid/rhabdoid tumors (AT/RT) and the causes of pathological misdiagnosis, and summarize diagnostic strategies.Methods:A case series study was conducted.Specifically, the data of 5 misdiagnosed(misdiagnosed group) and 8 confirmed AT/RT cases(confirmed group) in the Department of Pathology of Xi′an Children′s Hospital from January 2010 to December 2018 were retrospectively analyzed.Hematoxylin-eosin and immunohistochemical staining were performed to analyze clinical features, morphology, and immune phenotypes.Rates were compared between the misdiagnosed and confirmed groups by a Fisher′s exact test.Means were compared using an independent sample t-test.Medians were compared by a Mann-Whitney U test. Results:(1)There were 4 males and 1 female in the misdiagnosed group, with a median age of 24 months.In this group, 4/5 tumors were located in the posterior cranial fossa, and 1/5 tumors were located in the spinal cord.Morphologically, rhabdoid cells were detected in 3/5 cases, and the other 2/5 cases consisted of small embryonal cells.Immunohistochemically, INI1 and BRG1 expressions were absent in 4/5 and 1/5 cases, respectively.All of them showed multiple immunephenotypes.There were 7 males and 1 female in the confirmed group, with a median age of 22 months.In the confirmed group, 4/8 tumors were located in the supratentorial region and 4/8 tumors were located in the infratentorial region.Rhabdoid cells, deficient INI1 expression and multiple immunephenotypes were observed in all 8 cases.(2)The percentage of rhabdoid cells in the misdiagnosed group was significantly lower[0.45(0, 0.46)] than that in the confirmed group[0.55(0.40, 0.85)]( Z=-2.064, P=0.039). Conclusions:The causes of misdiagnosis of AT/RT are variable sites of occurrence, diverse histomorphology, multiple phenotypes in immunohistochemistry and rare BRG1 deficiency.For high-grade rhabdoid, epithelioid, and/or embryonic small cell tumors, AT/RT should be differentiated and immunohistochemistry protocols should include INI1 and BRG1.

Objective:To analyze the clinicopathological characteristics of atypical teratoid/rhabdoid tumors (AT/RT) and the causes of pathological misdiagnosis, and summarize diagnostic strategies.Methods:A case series study was conducted.Specifically, the data of 5 misdiagnosed(misdiagnosed group) and 8 confirmed AT/RT cases(confirmed group) in the Department of Pathology of Xi′an Children′s Hospital from January 2010 to December 2018 were retrospectively analyzed.Hematoxylin-eosin and immunohistochemical staining were performed to analyze clinical features, morphology, and immune phenotypes.Rates were compared between the misdiagnosed and confirmed groups by a Fisher′s exact test.Means were compared using an independent sample t-test.Medians were compared by a Mann-Whitney U test. Results:(1)There were 4 males and 1 female in the misdiagnosed group, with a median age of 24 months.In this group, 4/5 tumors were located in the posterior cranial fossa, and 1/5 tumors were located in the spinal cord.Morphologically, rhabdoid cells were detected in 3/5 cases, and the other 2/5 cases consisted of small embryonal cells.Immunohistochemically, INI1 and BRG1 expressions were absent in 4/5 and 1/5 cases, respectively.All of them showed multiple immunephenotypes.There were 7 males and 1 female in the confirmed group, with a median age of 22 months.In the confirmed group, 4/8 tumors were located in the supratentorial region and 4/8 tumors were located in the infratentorial region.Rhabdoid cells, deficient INI1 expression and multiple immunephenotypes were observed in all 8 cases.(2)The percentage of rhabdoid cells in the misdiagnosed group was significantly lower[0.45(0, 0.46)] than that in the confirmed group[0.55(0.40, 0.85)]( Z=-2.064, P=0.039). Conclusions:The causes of misdiagnosis of AT/RT are variable sites of occurrence, diverse histomorphology, multiple phenotypes in immunohistochemistry and rare BRG1 deficiency.For high-grade rhabdoid, epithelioid, and/or embryonic small cell tumors, AT/RT should be differentiated and immunohistochemistry protocols should include INI1 and BRG1.

To investigate the clinical efficacy of extended thymectomy by subxiphoid approach video-assisted thoracoscopic surgery(VATS) for myasthenia gravis. Methods We retrospectively analyzed the clinical date of 64 cases of myasthenia gravis treated by subxiphoid approach VATS in the same surgical team from September 2015 to April 2018. The patients were equally divided into 4 groups(A, B, C and D) according to the date of operation. Comparisons were made among the four groups in operation time, blood loss during operation, rate of conversion to thoracotomy, postoperative complications, postoperative hospital stay, duration and amount of postoperative chest tube drainage, frequenlly of surgery. The operative effect of different stage was analyzed. Results There were no intraoperative deaths. 1 patient(group A) was converted to thoracotomy. 3 patients(2 cases of group A; 1 case of group D) had lung infection. 1 patient(group B) developed myasthenia crisis after surgery, and the rest patients showed obvious improvement in postoperative myasthenia symptoms. No significant differences were found in postoperative complications, rate of conversion to thoracotomy, postoperative hospital stay, duration and amount of postoperative chest tube drainage among the 4 groups(P >0. 05). The operation time was significantly longer in group A(186. 25 ± 25. 79) min than the other 3 groups [B(128. 75 ± 16. 28) min, C(135. 00 ± 21. 29) min, D(128. 75 ± 19. 62)min], P <0. 05. The blood loss in surgery was significsntly more in group A(110. 00 ±38. 82)ml than that in the other 3 groups[B(63. 75 ±28. 26)ml, C(58. 13 ±27. 86)ml, D(58. 75 ±25. 00)ml], P <0. 05, while no statistical difference was found among group B, C and D. The frequency of surgery was increased from 1. 6 cases in group A to 2. 3, 2. 7 and 2. 7 cases one month in B, C and D, respectively. Conclusion The results of the present study have shown that subxiphoid approach VATS thymectomy is safe and feasible for the treatment of MG patients. For thoracic surgeons with certain experience in thoracoscopic technique, a plateau of the surgical skill of the subxiphoid opproach can be reached after learning curve procedures.