Background: The differential diagnosis of mucoepidermoid carcinoma (MEC) from neoplasm undergoing mucinous features brings more pitfalls to pathologists. Combining specific MAML2 gene rearrangement and histological characteristics may be the solution. Methods: Twenty-five tumors with mucinous components were selected for differential diagnosis of MEC. All the cases were detected for MAML2 gene rearrangement. The cases diagnosed as MEC were classified into four variants: classic, oncocytic, Warthin-like, and nonclassified, and they were graded using the Brandwein system. The histological characteristics of non-MECs were summarized for differential diagnosis. Univariate survival analysis was performed on MECs. Results: There were 16 MECs; 62.5% were MAML2 rearranged. For the low-, intermediate-, and high-grade MECs, the rate of rearrangement was 83.3%, 100%, and 28.6%, respectively. Both the oncocytic and Warthinlike MECs were MAML2 rearranged. For the classic and nonclassified MECs without MAML2 rearrangement, non-keratinized squamoid cells and distinctive mucinous cells were essential diagnostic criteria. On survival analysis, all the disease progression occurred in high-grade MECs (p = 0.038). Nine cases were diagnosed as non-MECs: pleomorphic adenoma with mucinous metaplasia showed no ex-capsular involvement; metaplastic Warthin tumor appeared with overt keratinization and residual oncocytic bilayered epithelium; mix squamous cell and glandular papilloma showed an endobronchial papillary growing pattern; adenosquamous carcinoma was accompanied by squamous carcinoma in situ of the overlying mucosa. All the non-MECs were negative for MAML2 rearrangement. Conclusion:The application of combining MAML2 rearrangement and histological characteristics is helpful in the differential diagnosis between MEC and other tumors with mucinous components.

Background: Despite great progress of surgery and other treatments, the prognosis of patients with esophageal squamous cell carcinoma (ESCC) is still very poor. HER2 has strong therapeutic implications in certain cancers, such as breast cancer and gastric cancer. However, literature on the frequency of HER2 expression in ESCC is scarce. In the present study, HER2 expression and gene amplification and the association of HER2 status with clinicopathological characteristics were evaluated in a large cohort of Chinese ESCC patients.Methods: A total of 857 consecutive patients who received radical esophagectomy without neoadjuvant chemotherapy were included in this retrospective study. HER2 expression was analyzed by immunohistochemistry (IHC), and its correlation with clinicopathological parameters was assessed. In addition, 65 cases, including 13 HER2 overexpression (3+) cases and 52 HER2 equivocal (2+) cases from the 857-case cohort, were selected to construct tissue microarrays (TMAs). Another 104 ESCC cases, which included 1 HER2 overexpression (3+) case, 3 HER2 equivocal (2+) cases and 100 HER2 negative (1+/0) cases, were also selected for TMA construction. Dual-color in situ hybridization (DISH) was performed on the TMAs to assess HER2 gene amplification.Results: We found HER2 overexpression (3+) status in 1.5% (13/857) of cases and HER2 equivocal (2+) status in 6.1% (52/857) of cases. HER2 expression was significantly associated with gender. HER2 equivocal (2+) expression was more likely to occur in females (P=0.028). Regarding the 169 cases analyzed by DISH, 14 (of 14, 100%) HER2 overexpression (3+) cases, 10 (of 55, 18.2%) HER2 equivocal (2+) cases, and 0 (of 100, 0%) HER2 negative (1+/0) cases showed HER2 gene amplification. HER2 gene amplification was not significantly associated with clinicopathological characteristics such as age, gender, tumor differentiation, pT stage, pN stage, pM stage and pTNM stage (P>0.05).Conclusions: Approximately 2% of the Chinese ESCC patients had HER2 overexpression based on IHC. HER2 expression was significantly associated with gender, HER2 gene amplification was not significantly associated with clinicopathological characteristics. IHC and DISH had a high concordance rate. These results provide valuable insight for the future treatment of ESCC.

Background: Recently, copy number alteration (CNA) of 9p24.1 were demonstrated in 10% of diffuse large b-cell lymphoma (DLBCL), with gene expression and mutation profiles that were similar to those of primary mediastinal large B-cell lymphoma(PMBCL). However, their CNA-based profile and clinical impact still remain unclear. Methods: Multiplex ligation-dependent probe amplification were employed to investigate the prevalence of JAK2/PD-L2 amplification in DLBCL and their CNA-based pattern of driver genes. The clinical outcome and characteristics were also analyzed. Results: Using unsupervised hierarchical clustering, a small group of DLBCL (11.7%, 9/77) was clustered together with PMBCL as Cluster_2, demonstrating amplification of JAK2 (100%,9/9) and PD-L2 (77.8%,7/9). This subgroups of DLBCL demonstrated significant higher expression of PD-L1 than those with MYD88 L265P mutation(p=0.011). And they exhibited dismal OS and PFS as compared with DLBCL_others(p=0.021 and 0.015, respectively), which is similar to DLBCL with MYD88 L265P mutation. Conclusions: DLBCL with amplification of JAK2/PD-L2 exhibits CNA pattern that is similar to PMBCL, and worse clinical outcome that resembles those with MYD88 L265P mutation.