Objective:To investigate the expression level of synaptophysin (Syn), tissue neuronal cell adhesion molecule 56 (CD56) and chromogranin A (CgA) in 92 primary esophageal small cell carcinoma (PESC) and to explore its repationship with clinicopathological features and clinical outcome. Methods:Immunohistochemical studies of CD56, CgA, and Syn were performed in 92 paraffin-embed-ded tissues with clinical-related information obtained from 500,000 esophageal and gastric cardia carcinoma databases established by Henan Key Laboratory for Esophageal Cancer Research of the First Affiliated Hospital of Zhengzhou University in Henan, China. Binary logistic regression was used to analyze the correlations of CgA, Syn, and CD56 expression with clinicopathological features. Kaplan-Mei-er survival analysis and Cox proportional hazards regression models were performed for univariate and multivariate survival analyses. Log-rank test was used to compare the difference in survival rates. Results:The CgA-positive expression rate in PESC at lower segment of esophagus (72.2%) was higher than those at the middle and lower segments (41.1%, 10.0%) (P=0.001). The expression level of CD56, CgA, and Syn was not correlated with gender (P=0.262, 0.998, 0.931), age (P=0.250, 0.998, 0.703), tumor invasion (P=0.253, 0.997, 0.061), and lymph node metastasis (P=0.767, 0.998, 0.613). Univariate analysis showed no survival influence in patients with and without lymph node metastasis (P=0.563). Multivariate survival analysis showed that patients with PESC mixed squamous cell car-cinoma (HR=2.58;95%Cl, 1.11-5.98) and higher CgA protein expression (HR=1.87;95%Cl, 1.02-3.43) exhibited a longer survival time than those with pure PESC and without CgA expression. Conclusion:Tissue CgA level was associated with tumor location in PESC. His-tological type and tissue CgA expression were independent important prognostic factors, and lymph node metastasis exerted no influ-ence on survival in PESC.

Objective:To characterize the histopathological subtypes and their clinicopathological parameters of gender and onset age by common, rare and sparse primary esophageal malignant tumors (PEMT).Methods:A total of 272 437 patients with PEMT were enrolled in this study, and all of the patients were received radical surgery. The clinicopathological information of the patients was obtained from the database established by the State Key Laboratory of Esophageal Cancer Prevention & Treatment from September 1973 to December 2020, which included the clinical treatment, pathological diagnosis and follow-up information of esophagus and gastric cardia cancers. All patients were diagnosed and classified by the criteria of esophageal tumor histopathological diagnosis and classification (2019) of the World Health Organization (WHO). The esophageal tumors, which were not included in the WHO classification, were analyzed separately according to the postoperative pathological diagnosis. The χ 2 test was performed by the SPSS 25.0 software on count data, and the test standard α=0.05. Results:A total of 32 histopathological types were identified in the enrolled PEMT patients, of which 10 subtypes were not included in the WHO classification. According to the frequency, PEMT were divided into common (esophageal squamous cell carcinoma, ESCC, accounting for 97.1%), rare (esophageal adenocarcinoma, EAC, accounting for 2.3%) and sparse (mainly esophageal small cell carcinoma, malignant melanoma, etc., accounting for 0.6%). All the common, rare, and sparse types occurred predominantly in male patients, and the gender difference of rare type was most significant (EAC, male∶ female, 2.67∶1), followed with common type (ESCC, male∶ female, 1.78∶1) and sparse type (male∶ female, 1.71∶1). The common type (ESCC) mainly occurred in the middle thoracic segment (65.2%), while the rare type (EAC) mainly occurred in the lower thoracic segment (56.8%). Among the sparse type, malignant melanoma and malignant fibrous histiocytoma were both predominantly located in the lower thoracic segment (51.7%, 66.7%), and the others were mainly in the middle thoracic segment.Conclusion:ESCC is the most common type among the 32 histopathological types of PEMT, followed by EAC as the rare type, and esophageal small cell carcinoma and malignant melanoma as the major sparse type, and all of which are mainly occur in male patients. The common type of ESCC mainly occur in the middle thoracic segment, while the rare type of EAC mainly in the lower thoracic segment. The mainly sparse type of malignant melanoma and malignant fibrous histiocytoma predominately occur in the lower thoracic segment, and the remaining sparse types mainly occur in the middle thoracic segment.