血管扩张Angiectasis · 肝 · 肝胆系统 · NTP ntp-0423
诊断要点：血管扩张只要作为独立事件存在，就应记录并分级，但若与另一病变（如灶性病变或肿瘤）相关，则不应诊断。
病变描述
局灶性（focal） 和 多灶性（multifocal） 血管扩张（angiectasis）（Figure 1、Figure 2）可自发发生，且随动物年龄增长而更频繁出现，但也可由亚硝胺（nitrosamines）等化学物质引起。其由扩张的血窦腔隙构成，内衬外观正常的内皮细胞（endothelial cell）（Figure 3）。在较大的扩张腔隙中，内皮细胞可增生以衬覆扩张的腔隙。邻近血管扩张腔隙的肝细胞可正常或轻度萎缩。血管扩张与囊性变性（cystic degeneration）的鉴别在于内皮衬覆的通道内存在红细胞。显著（marked） 的血管扩张病例与血管瘤（hemangioma）之间的区分常不明确。
诊断与分级建议（NTP 共识）
血管扩张只要作为独立事件存在，就应记录并分级，但若与另一病变（如灶性病变或肿瘤）相关，则不应诊断。扩张腔隙的数量及其扩张程度将影响分级。任何提示治疗诱导的血管扩张的迹象均应记录、分级，并在病理学叙述中描述。
图谱
英文原文
展开 NTP 官方英文描述与建议
Comment：
Focal and multifocal angiectasis ( Figure 1 and Figure 2 ) occurs spontaneously, and more frequently as animals age, but it can also be caused by chemicals such as nitrosamines. It consists of dilated sinusoidal spaces that are lined by normal-appearing endothelial cells ( Figure 3 ). In larger dilated spaces, endothelial cells may multiply to line the dilated spaces. Hepatocytes adjacent to angiectatic spaces may be normal or slightly atrophic. Angiectasis is distinguished from cystic degeneration by the presence of erythrocytes in endothelial-lined channels. The distinction between marked cases of angiectasis and hemangioma is often unclear.
Recommendation：
Angiectasis should be documented and graded whenever present as an independent event but should not be diagnosed if it is associated with another lesion, such as a focus or a neoplasm. The number of dilated spaces and their degree of dilation will influence grading. Any indication of treatment-induced angiectasis should be recorded, graded, and described in the pathology narrative.
来源与引用
原始条目：https://ntp.niehs.nih.gov/atlas/nnl/hepatobiliary-system/liver/Angiectasis
图谱总目录：NTP Nonneoplastic Lesion Atlas。 内容属美国联邦政府作品（公有领域），可引用；引用时请标注来源。
建议引用格式：NTP Nonneoplastic Lesion Atlas. Angiectasis (liver). LabSmart 中文版：
https://www.labsmart.cn/ntp/liver-angiectasis.html
中文图谱总页（可展开对照全部 595 条）：https://www.labsmart.cn/ntp-atlas.html#liver-angiectasis