食管胃交界处的心脏粘膜是否正常或化生是有争议的。试图解决这个问题的研究受到了使用浅层捏活检的限制,异常食道切除通常是因为癌症,或尸检标本,其中胃中的组织自溶掩盖了组织学发现。
我们对7次心跳切除的新鲜固定的食道和胃进行了组织学和免疫组织化学研究,已故器官捐献者,无食道或胃病史,食管炎和胃炎的组织学证据很少或没有。
所有受试者都有心脏粘膜,由粘液腺和血氧腺与表面小窝上皮的混合物组成,在食管胃交界处.都有独特的结构,我们称之为致密粘液腺(CMG),在组织学和免疫组织化学上与心脏粘膜的粘液腺相同,在食管鳞状上皮和,迄今没有描述,在整个胃底未发炎的氧化粘膜中。
这些发现支持心脏粘膜作为正常的解剖结构,并不支持心脏粘膜总是化生的假说。然而,他们确实支持我们的新假设,即在反流性食管炎的背景下,反流诱导的鳞状上皮损伤暴露了下方的CMG(可能比鳞状上皮对酸-消化性损伤更有抵抗力),这些CMG的增殖作为伤口愈合过程的一部分来修复酸消化性损伤,可能导致它们扩张到粘膜表面,被认为是柱状衬里食道的心脏粘膜。
Whether cardiac mucosa at the esophagogastric junction is normal or metaplastic is controversial. Studies attempting to resolve this issue have been limited by the use of superficial pinch biopsies, abnormal esophagi resected typically because of cancer, or autopsy specimens in which tissue autolysis in the stomach obscures histologic findings.
We performed histologic and immunohistochemical studies of the freshly fixed esophagus and stomach resected from 7 heart-beating, deceased organ donors with no history of esophageal or gastric disease and with minimal or no histologic evidence of esophagitis and gastritis.
All subjects had cardiac mucosa, consisting of a mixture of mucous and oxyntic glands with surface foveolar epithelium, at the esophagogastric junction. All also had unique structures we termed compact mucous glands (CMG), which were histologically and immunohistochemically identical to the mucous glands of cardiac mucosa, under esophageal squamous epithelium and, hitherto undescribed, in uninflamed oxyntic mucosa throughout the gastric fundus.
These findings support cardiac mucosa as a normal anatomic structure and do not support the hypothesis that cardiac mucosa is always metaplastic. However, they do support our novel hypothesis that in the setting of reflux esophagitis, reflux-induced damage to squamous epithelium exposes underlying CMG (which are likely more resistant to acid-peptic damage than squamous epithelium), and proliferation of these CMG as part of a wound-healing process to repair the acid-peptic damage could result in their expansion to the mucosal surface to be recognized as cardiac mucosa of a columnar-lined esophagus.