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颈部血管瘤为先天性疾病，是血管在胚胎发育的过程中，使血管的某一阶段发育障碍，使其形态停止在该阶段。血管瘤是由大量增生的血管所构成。胚胎早期，原始脉管是一种单纯由内皮细胞组成的管状物，它们在间质中间形成一个致密的网。以后随着各器官的发育，原始脉管网逐渐分化成与器官联系的许多血管丛和淋巴管丛。
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