Fajardo Luis Felipe
Stanford University School of Medicine and Veterans Affairs Health Care System, Palo Alto, California 94304-1290, USA.
Acta Oncol. 2005;44(1):13-22. doi: 10.1080/02841860510007440.
This article presents a brief description of the effects of ionizing radiation in human tissues, as seen by the Pathologist. The lesions that occur in multiple organ/tissues will be discussed, dividing them into those that affect (a) the parenchyma or epithelia, (b) the stromal elements, and (c) the blood vessels. Since not all lesions fit into these patterns, the exceptions will be described as characteristic organ lesions. Unless specified otherwise the alterations presented are those that result from electromagnetic radiation (x-rays and gamma rays) as used for clinical radiation therapy. Most of the material presented will be delayed injury (i.e. months-to-years after exposure). The epithelial/parenchymal lesions include atrophy, necrosis, metaplasia, cellular atypia, dysplasia, and neoplasia. The common stromal lesions--the best recognized by pathologists--include fibrosis, fibrinous exudates, necrosis (with a paucity of cellular inflammatory exudates), and atypical fibroblasts. The vascular lesions are quite consistent: most often they affect the microvessels (capillaries, sinusoids) producing lethal and sublethal damage to the endothelial cells, with capillary rupture or thrombosis. Medium-size vessels show neointimal proliferation, fibrinoid necrosis, thrombosis, or acute arteritis. Damage in large vessels is less common; it occurs more in arteries than in veins and includes neointimal proliferation, atheromatosis, thrombosis and rupture (a dramatic complication). Some of the characteristic organ lesions are veno-occlusive liver disease, acute radiation pneumonitis, permanent bone marrow hypoplasia or aplasia, and colitis cystica profunda. Neoplasms are a well-recognized delayed complication of radiation and will not be described in detail. It is important to remember that there are no pathognomonic features of injuries produced by ionizing radiation. Nonetheless, although not specific individually, the combined features are characteristic enough to be recognized.
本文简要描述了病理学家所观察到的电离辐射对人体组织的影响。将讨论发生在多个器官/组织中的病变，并将它们分为影响（a）实质或上皮、（b）间质成分和（c）血管的病变。由于并非所有病变都符合这些模式，将把例外情况描述为特征性器官病变。除非另有说明，所呈现的改变是由临床放射治疗中使用的电磁辐射（X射线和γ射线）引起的。所呈现的大多数材料将是延迟性损伤（即暴露后数月至数年）。上皮/实质病变包括萎缩、坏死、化生、细胞异型性、发育异常和肿瘤形成。常见的间质病变——病理学家最容易识别的——包括纤维化、纤维素渗出、坏死（细胞炎性渗出物较少）和非典型成纤维细胞。血管病变相当一致：最常影响微血管（毛细血管、血窦），对内皮细胞造成致死性和亚致死性损伤，伴有毛细血管破裂或血栓形成。中等大小的血管表现为内膜增生、纤维蛋白样坏死、血栓形成或急性动脉炎。大血管损伤较少见；更多发生在动脉而非静脉，包括内膜增生、动脉粥样硬化、血栓形成和破裂（一种严重并发症）。一些特征性器官病变是肝静脉闭塞病、急性放射性肺炎、永久性骨髓发育不全或再生障碍以及深部囊性结肠炎。肿瘤是公认的辐射延迟并发症，将不详细描述。重要的是要记住，电离辐射所致损伤没有特异性特征。尽管如此，虽然单个特征不具特异性，但综合特征足以被识别。
