局灶性结节状增生中变异肝细胞结节的检出及其与肝细胞腺瘤的比较

Identification of nodules of altered hepatocytes from focal nodular hyperplasia, with comparison to hepatocellular adenoma

目的研究局灶性结节状增生（FNH）与变异肝细胞病灶（FAH）和结节（NAH）的关系，并对其微血管结构以及细胞增生活性与肝细胞腺瘤（HCA）进行对比观察。方法对5例患者的6个经典FNH和9例患者的10个HCA进行组织学观察，应用免疫组织化学方法检测CD34、Ki-67抗原和细胞角蛋白19（CK19）表达，计算Ki-67标记指数以反映细胞增生活性。结果6个FNH病变中均检测到多个FAH和NAH。HCA和FNH组织中均有CD34标记的微血管，但其密度和分布不同。HCA中微血管弥漫存在；FNH中微血管呈灶性或小结节状分布，主要存在于NAH中。CK19标记显示，FNH中胆小管和胆管阳性，NAH和HCA均为阴性。FNH中，73个NAH的Ki-67标记指数（2．8％）明显高于FNH内NAH未累及的肝实质（0．6％），但与HCA（1．8％）相比差异无统计学意义。结论经典FNH中常见NAH形成，NAH与周围肝实质不同，具有较高的细胞增殖活性以及类似于HCA的CD34阳性微血管结构。

Objective Focal nodular hyperplasia （FNH） is composed of multiple hyperplastic liver cell nodules, but its pathogenesis has not been elucidated. Foci （FAH） or nodules of altered hepatocytes （NAH） are precursors of hepatocellular adenoma （HCA） and carcinoma. This study aimed at identifying FAH and NAH from FNH and evaluating their role in FNH development. Methods 6 FNH lesions from 5 patients and 10 HCA from 9 patients were examined histologically, and expression levels of CD34, cytokeratin 19（CK19） and Ki-67 antigen were demonstrated immunohistochemically. Proliferative activity was evaluated by Ki-67 antigen-labeling indices （Ki-67 LI）. Results Multiple FAH and NAH were identified in all of the 6 FNH lesions. While microvasculatures were demonstrated by CD34 immunoreactivity in both HCA and FNH, their density and distribution were different in these two lesions, being diffuse in HCA and focal or nodular, mainly within NAH. CK19 expression was found in FNH, localized in duetal and ductular cells, but not within NAH and HCA. Average Ki-67 LI of 73 NAH （2.8 %） was shown to be higher than that of the whole FNH lesions （0.6 %）, and had no statistical difference comparable to that of HCA （1.8 %）. Conclusion Multiple NAH are present in all classical FNH lesions. Unlike the surrounding parenehyma, NAH lesions are more proliferative and equipped with CD34-positive microvasculatnres as in HCA.