Nakashima O, Kojiro M
First Department of Pathology, Kurume University School of Medicine, Japan.
Gan To Kagaku Ryoho. 1996 Jun;23(7):827-34.
Recent advances in various diagnostic imagings have made possible early diagnosis of hepatocellular carcinoma (HCC). Grossly, small HCCs of the early stage up to around 1.5 cm in diameter are vaguely demarcated from surrounding liver tissue. Such minute tumors are classified as small HCC with indistinct margins. Histologically, these tumors consist of uniform distribution of well-differentiated cancerous tissues, which are characterized by increased cell density with increased nuclear/cytoplasmic ratio, irregular thin-trabecular pattern with occasional pseudoglandular structure, and frequent fatty and/or clear cell change. In all small HCCs with indistinct margins, varying numbers of portal tracts are contained within the cancerous tissues. None of them represents invasion of the portal vein or intrahepatic metastasis. Thus, small HCC with indistinct margins is considered to be HCC of the earliest stage that can be clinically detected at this moment. Along with the increase of resected small HCCs, hyperplastic lesions such as adenomatous hyperplasia (AH) and atypical AH, which are difficult to differentiate from well-differentiated HCC have also been found. Atypical AH is considered a borderline malignancy. Some focal nodular hyperplasias and liver cell adenomas are also difficult to differentiate from well-differentiated HCC. It should be recalled that some metastatic tumors such as carcinoid tumor, renal cell carcinoma and hepatoid adenocarcinoma also resemble HCC.
各种诊断成像技术的最新进展使肝细胞癌（HCC）的早期诊断成为可能。大体上，直径达1.5 cm左右的早期小肝癌与周围肝组织界限不清。这种微小肿瘤被归类为边界不清的小肝癌。组织学上，这些肿瘤由分化良好的癌组织均匀分布组成，其特征为细胞密度增加、核/质比增加、呈不规则细小梁状结构并偶见假腺管结构，以及常见脂肪和/或透明细胞改变。在所有边界不清的小肝癌中，癌组织内均包含数量不等的门静脉分支。它们均不代表门静脉侵犯或肝内转移。因此，边界不清的小肝癌被认为是目前临床上能够检测到的最早阶段的肝癌。随着切除的小肝癌数量增加，还发现了一些难以与高分化肝癌相鉴别的增生性病变，如腺瘤样增生（AH）和非典型AH。非典型AH被认为是一种交界性恶性肿瘤。一些局灶性结节性增生和肝细胞腺瘤也难以与高分化肝癌区分。应当记住，一些转移性肿瘤，如类癌、肾细胞癌和肝样腺癌也与肝癌相似。
