医学英语：癌细胞扩散

4As a pathologic entity, cancer is defined by its properties of uncontrolled local proliferation of cells,

作为病理学实体，癌症指的是细胞恶性繁殖，且不可控，

with invasion of adjacent normal structure and by distant spread, or metastasis, via the bloodstream of lymphatic or within a body cavity.

并破坏周边正常细胞组织，通过淋巴系统或在体腔内完成转移。

As a biologic entity, the malignant cell is defined by its ability to grow in tissue culture without the need for attachment to a firm surface

作为生物体，肿瘤细胞的恶性性质是由下面因素决定的：在组织培养时，它无需附着于坚固的表面就能生长，

and by its loss of responsiveness to growth regulatory signals that cause differentiation and suppress proliferation.

并且它对能够引起分化和抑制增生的生长调节信号没有反应。

Many malignant cells preserve the growth and antigenic properties characteristic of fetal cells，

许多肿瘤细胞会继续增长，以及具有抗原性的癌胚细胞，

secrete proteins characteristic of fetal tissues ( such as the a-fetoprotein of hepatocellular carcinomas and germ-cell tissues) ,

还可分泌具有癌胚组织特性的蛋白质（例如肝癌细胞的甲胎蛋白和生殖细胞组织），

and appear to be frozen in an early state of differentiation that recapitulates a specific stage in normal organ development.

在正常器官生长的特殊阶段-分化，癌细胞处于冷冻状态。

For example, malignancies arising from the lymphoid system reflect all stages and types of B-and T-lymphocyte development and preserve the same complex of immunoglobulin

例如，淋巴系统中恶性肿瘤会体现在所有阶段，T淋巴细胞和B淋巴细胞的发展也同样如此，它保留了免疫球蛋白的复杂性，

and T-cell receptor gene rearrangement and cell surface proteins ( and in some cases potential for future differentiation) found in normal counterparts of the immune system.

T细胞受体基因重排以及细胞表面蛋白质（在许多情况下，这些细胞会继续分化），我们可以在正常的免疫系统中发现。

These properties have become the basis for classification, diagnosis, and even treatment of tumors,

这些特性是进行分类、诊断甚至是治疗的基础，

as, for example, classification of lymphoid tumors based on reactivity with monoclonal antibodies.

例如根据单克隆抗体为基础的淋巴细胞分类。

While the above characteristics are typical of most cancer cells, they are not universal.

上述特性适用于多数癌细胞，但它们不是普遍的。

Some endocrine-related tumors, for example, not only maintain well-differentiated morphologic features of their tissue of origin

例如一些内分泌相关肿瘤，它们在形态上就维持了组织初期的良好分化，

but also retain endocrine function and produce bioactive hormonal substances typical of the mature tissue, as in pheochromocy-tomas.

还保留了内分泌功能，并产生了成熟组织具备的生物活性激素，比如同嗜铬细胞瘤。