A Systematical Study On The Length Of Cardiac Mucosa And The Histological And Histochemical Characters Of The Cardiac Mucosa And Esophageal Glands

1 BACKGROUND AND OBJECTIVEThe increasing incidence of the adenocarcinomas of the gastroesophageal junction(GEJ) in many countries has attracted the attention of more and more scholars worldwide.Especially,the gastric cardia cancer shows increasing trend in China.However,no agreement on the definition and diagnostic standards of gastric cardia adenocarcinomas has been achieved so far,which is mainly attributed to the uncertainty of exact localization of cardia.Traditionally,the cardia was referred to be the conjunction region between the distal esophagus and stomach.Hitherto,a number of studies on cardiac mucosa have been reported,among which the main difference was confined to the length,origin and relationship with carcinogenesis in the gastroesophageal junction.The diagnostic standard of gastric cardia adenocarcinomas is not unified,for the localization and definition of cardia are still in dispute.This situation makes it difficult to make correct division of the tumor.Therefore,it is rather urgent to define the gastric cardia in the research of the adenocarcinomas of GEJ.The esophageal glands at GEJ were composed of mucous cells and located within the esophagus,and the relationship between these glands and the adenocarcinomas of GEJ remained unclear up to now.So,defining the localization of gastric cardia and studying esophageal glands would be crucial for better understanding Barrett's esophagus and gastric cardia adenocarcinomas.As a result,this study aims to measure the length of cardiac mucosa and analyse the histological and histochemical characters of gastric cardiac as well as of esophageal glands on the surgically resected specimens with esophageal cancer or gastric cardia adnocarcinoma.2 MATERIALS AND METHODS2.1 SubjectsIn this study,214 surgically resected specimens were provided by Linzhou Center Hospital and Yaocun Esophageal Cancer Hospital,Henan Province,China,among which 123 were males and 91 were females,with the age ranged between 47 and 72 years(median 61±5 years).No patients received preoperative radiotherapy or chemotherapy.Of the 214 specimens under survey,128 belong to esophageal cancer, whose distal tumors margin were located＞5cm from the GEJ;whereas the rest 86 samples were with gastric cardia cancer,in which the distance between the tumors and the GEJ were＞1.5cm.2.2 Tissue samples processingOnly the specimen with integrated and clear GEJ was considered here.The dissected tissue contained a part of esophagus 2cm above the GEJ and partial gastric cardia 3cm beneath the GEJ.The tissue was fixed with 85%ethanol,embedded by paraffin,and serially cut into sections with thickness of 5μm.2.3 MethodsFor the obtained two neighboring sections of the same tissue,the first one was stained with HE whereas another one was stained with AB-PAS.The stained slides were evaluated using the optical microscope and measurement software.SPSS13.0 was adopted for statistical calculation,and P＜0.05 was considered as statistically significant. 3 RESULTS3.1 Shrinkage of esophageal and gastric cardia tissueObvious shrinkage is observed for esophageal specimens after resection and fixation,and the shrinkage rates were 42%and 31%,respectively.No significant difference between these two rates was observed(P＞0.05).Similarly,the gastric cardia specimens also showed the shrinkage to esophagus after either resection or fixation,and the rates were 32%and 24%,respectively.The difference between the two rates was significant(P＜0.05).The total shrinkage rates for esophagus and gastric cardia from resection to fixation were 64%and 49%,respectively(P＜0.05).3.2 The gastric cardiac mucosaThe gastric cardiac glands were composed of mucous cells.After stained with HE, the cytoplasm of mucous cell was colored lightly,and these glands were often lobulated and have an inconstant architecture.These glands were dark red stained with AB-PAS.The gastric cardiac mucosa was 1.45±0.43cm(ranging from 0.51era to 2.4cm). The mean lengths of cardiac mucosa with and without gastroesophageal reflux disease were 1.47cm and 1.33cm,respectively.The difference was insignificant(P＞0.05).The mean lengths of cardiac mucosa in the cases with and without esophageal glands were 1.34cm and 1.53cm,respectively.The difference was not statistical significance (P＞0.05).3.3 The esophageal glandsThe total incidence rate of esophageal glands was 56%.In esophageal and gastric cardia cancer the rates were 54%and 58%,respectively.The rates of with and without gastroesophageal reflux disease were 61%and 51%,respectively.The all different rates have no statistical significance(P＞0.05).The esophageal glands were mainly composed of mucous cells.Stained with AB-PAS,they showed the same color with the gastric cardiac glands.4 CONCLUSIONS3.1 The dynamic shrinkage is observed for esophageal and gastric cardia specimens after resection and fixation.The shrinkage rate in esophagus is higher than in gastric cardia,which varies under different conditions of resection and fixation.3.2 The gastric cardiac mucosa is a common tissue with normal structure,which separates the distal portion of esophageal squamous epithelium from the gastric fundic mucosa instead of arising secondary to gastroesophageal reflux disease.The mean length of the mucosa is 1.45cm,and is close to 3cm in-situ.3.3 The esophageal gland is a normal tissue,and it varies markedly among different individuals.Its histological and histochemical characters are all similar to the gastric cardiac gland.