Duplication of the muscularis mucosae in Barrett esophagus: An underrecognized feature and its implication for staging of adenocarcinoma
Duplication of the muscularis mucosae in Barrett esophagus: An underrecognized feature and its implication for staging of adenocarcinoma
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DOI：
10.1097/pas.0b013e318093e3bf
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发表时间：
2007-11-01
影响因子：
5.6
通讯作者：
Wu, Tsung-Teh
中科院分区：
文献类型：
--
作者：
Abraham, Susan C.;Krasinskas, Alyssa M.;Wu, Tsung-Teh
浸润深度是食管腺癌最重要的预后指标之一。与胃肠道的其他区域不同，巴雷特化生中的食道经常出现粘膜肌层（MM）的重复，但这一特征尚未得到充分认识，而且它对表面侵袭性腺癌适当分期的影响尚不清楚。我们首先随机选择了50例Barrett食管（BE）高度异型增生或T1腺癌的食管切除术，以评估MM重复对BE及其组织学特征的敏感性和特异性，包括MM重复累及Barrett段的百分比，重复肌层的起源，20例食管鳞状细胞癌切除术作为对照。接下来，为了研究多发性骨髓瘤重复的临床意义，我们评估了30例局限于多发性骨髓瘤区域的浅表腺癌的BE切除术。每例病例被分类为：浸润深度（内部多发性骨髓瘤，多发性骨髓瘤之间的空间，或外部多发性骨髓瘤），血管淋巴浸润，淋巴结转移率。我们在50例BE切除中的46例（92%）中观察到MM重复，涉及5%至> 90%的Barrett段，而在20例（0%）切除的鳞状细胞癌中没有MM重复，P < 0.0001。在5例（10%）病例中，MM局灶性三重。外部MM与鳞状上皮下的单个MM连续，表明外部MM代表“原始”肌肉层。重复MM之间的空间主要由类似于粘膜下层的松散纤维血管组织组成;在15例（30%）病例中，还存在纤维化区域或连接2个MM层的细肌束。侵犯多发性骨髓瘤的30例中，10例（33%）仅侵犯内部骨髓瘤，12例（40%）侵犯骨髓瘤间间隙，8例（27%）侵犯外部骨髓瘤。5例（17%）有血管淋巴管浸润，3例（10%）有淋巴结转移，1例侵犯内部骨髓瘤，1例侵犯骨髓瘤间间隙，1例侵犯外部骨髓瘤。这些数据表明，MM重复是BE的特征性发现，但它可能对浅表腺癌的正确分期造成困难。在我们的重复MM患者中，17%的血管淋巴浸润率和10%的淋巴结转移率表明，尽管这些肿瘤在技术上位于粘膜内，但它们仍具有侵袭性。
Depth of invasion is one of the most important prognostic indicators in esophageal adenocarcinoma. Unlike other regions of the gastrointestinal tract, the esophagus in Barrett metaplasia frequently develops duplication of the muscularis mucosae (MM), but this feature is underrecognized, and its effect on appropriate staging of superficially invasive adenocarcinoma is unclear. We first randomly selected 50 esophageal resections for high-grade dysplasia or T1 adenocarcinoma in Barrett esophagus (BE) to evaluate the sensitivity and specificity of MM duplication for BE and its histologic characteristics, including percentage of the Barrett segment involved by MM duplication, origin of the duplicated muscle layer, and appearance of the tissue between duplicated MM. Twenty esophageal resections for squamous cell carcinoma served as controls. Next, to study the clinical significance of MM duplication, we evaluated 30 resections for BE that had superficial adenocarcinoma confined to regions of duplicated MM. Each case was classified as: depth of invasion (inner MM, space between duplicated MM, or outer MM), angiolymphatic invasion, and rate of lymph node metastasis. We observed MM duplication in 46 of 50 (92%) BE resections, involving 5% to > 90% of the Barrett segment, in contrast to none in 20 (0%) resected squamous cell carcinoma, P < 0.0001. In 5 (10%) cases, the MM was focally triplicated. The outer MM was continuous with the single MM beneath squamous epithelium, suggesting that outer MM represents the "original" muscle layer. The space between duplicated MM predominantly consisted of loose fibrovascular tissue similar to submucosa; in 15 (30%) cases, there were also areas of fibrosis or thin muscle strands joining the 2 MM layers. Of 30 adenocarcinomas invading duplicated MM, 10 (33%) invaded only inner MM, 12 (40%) invaded the space between MM, and 8 (27%) invaded the outer MM. Angiolymphatic invasion was present in 5 (17%) cases, and nodal metastases in 3 (10%, 1 case each of invasion into inner MM, between MM, and outer MM). These data show that MM duplication is a characteristic finding in BE, but it can pose difficulty in proper staging of superficial adenocarcinomas. The 17% rate of angiolymphatic invasion and 10% rate of lymph node metastases in our patients with invasion into duplicated MM suggest that these tumors can behave aggressively despite their technically intramucosal location.