Supplementary Material for: Endoscopic diagnosis of epithelial subtypes of superficial non-ampullary duodenal epithelial tumors using magnifying narrow-band imaging.

Introduction: Superficial non-ampullary duodenal epithelial tumors (SNADETs) include low-grade adenoma (LGA) and high-grade adenoma or carcinoma (HGA/Ca), and are classified into two different epithelial subtypes, gastric-type (G-type) and intestinal-type (I-type). We attempted to distinguish them by endoscopic characteristics including magnifying endoscopy with narrow-band imaging (M-NBI).
Methods: Various endoscopic and M-NBI findings of 286 SNADETs were retrospectively reviewed and compared between G- and I-types and histological grades. M-NBI findings were divided into four patterns based on the following vascular patterns; absent, network, intrastructural vascular (ISV), and unclassified. Lesions displaying a single pattern were classified as mono-pattern and those displaying multiple patterns as mixed-pattern. Lesions showing CDX2 positivity were categorized as I-types and those showing MUC5AC or MUC6 positivity were categorized as G-types based on immunohistochemistry.
Results: Among 286 lesions, 23 (8%) were G-type and 243 (85%) were I-type. More G-type lesions were located oral to papilla (91.3％ vs 45.6％, P<0.001), and had protruding morphology compared to those of I-types (65.2% vs 14.4%, P<0.001). The major M-NBI pattern was ISV in G-type (78.2% vs 26.3％, P<0.001), and absent for I-type (0% vs 34.5%, P=0.003). Three endoscopic characteristics; location oral to papilla, protruding morphology and major M-NBI pattern (ISV) were independent predictors for G-type. Mixed-pattern was more common in HGA/Ca than LGA for I-type (77.0% vs 58.8%, P＝0.01); however, there was no difference for those in G-type.
Conclusion: Endoscopic findings including M-NBI is useful to differentiate epithelial subtypes.

引言：浅表非壶腹十二指肠上皮肿瘤（Superficial non-ampullary duodenal epithelial tumors, SNADETs）包含低级别腺瘤（low-grade adenoma, LGA）与高级别腺瘤或癌（high-grade adenoma or carcinoma, HGA/Ca），并可分为胃型（gastric-type, G-type）、肠型（intestinal-type, I-type）两种不同上皮亚型。本研究尝试通过包括窄带成像放大内镜（magnifying endoscopy with narrow-band imaging, M-NBI）在内的内镜特征对其进行鉴别。
方法：本研究对286例SNADETs的各类内镜及M-NBI表现进行回顾性分析，并对比G型与I型肿瘤及不同组织学分级之间的差异。根据血管形态特征，M-NBI表现被分为四种模式：无血管模式、网状血管模式、结构内血管（intrastructural vascular, ISV）模式及未分类模式。仅表现为单一模式的病变归类为单模式型，表现为多种模式的病变归类为混合模式型。根据免疫组化结果，CDX2阳性的病变被归类为I型，MUC5AC或MUC6阳性的病变被归类为G型。
结果：在286例病变中，23例（8%）为G型，243例（85%）为I型。G型病变更多位于乳头口侧（91.3% vs 45.6%，P<0.001），且相较于I型病变更易呈隆起型形态（65.2% vs 14.4%，P<0.001）。G型的主要M-NBI模式为ISV模式（78.2% vs 26.3%，P<0.001），而I型则以无血管模式为主（0% vs 34.5%，P=0.003）。三项内镜特征——乳头口侧位置、隆起型形态及主要M-NBI模式（ISV模式）为G型的独立预测因素。对于I型病变，混合模式在HGA/Ca中较LGA更为常见（77.0% vs 58.8%，P=0.01）；但在G型病变中则无此差异。
结论：包括M-NBI在内的内镜表现可有效鉴别上皮亚型。