系统性淀粉样变性的超微病理诊断

The ultrapathological diagnosis of systemic amyloidosis

目的:应用光镜(LM)及透射电镜(TEM)观察不同部位淀粉样物质的沉积及超微结构特点,为系统性淀粉样变性提供可靠的病理诊断依据。方法:对21例临床拟诊为系统性淀粉样变性病例的肾脏,腹壁脂肪和直肠粘膜活检组织按常规进行LM及TEM标本制备及病理检查。结果:LM观察显示淀粉样物质在肾脏,腹壁脂肪和直肠粘膜沉积阳性率分别为76.2%(16/21)、38.1%(8/21)和9.5%(2/21),TEM观察显示淀粉样物质为排列不规则,中等致密,不均匀的絮状结构,直径约为10nm的纤维丝状结构,排列杂乱呈密网状,局灶区可排列呈束状,无分支,无颗粒状结构沉积。在肾脏节段系膜区、系膜旁区和节段基膜上皮下区以及腹壁脂肪和直肠粘膜的细小动脉内皮细胞基膜下,其阳性率分别为90.5%(19/21)、66.7%(14/21)和42.9%(9/21)。结论:电镜超微病理观察可以对系统性淀粉样变性提供可靠的诊断依据,肾脏活检的阳性率最高,对难于进行肾脏活检的病例可采用较安全的腹壁脂肪或直肠粘膜活检。

Objective： To observe the histological and ultrastructure features of systemic amyloidosis by using light microscope（LM） and transmission electron microscope（TEM）.Methods： The biopsy specimens of kidney,adipose tissue of abdominal wall and rectal mucous membrane were obtained from 21 patients with systemic amyloidosis and processed by routine HE and Congo red stain for LM and thinsection for EM.Results： Under LM,the percentages of positive amyloid deposits in the biopsy specimens of kidney,adipose tissue of abdominal wall and rectal mucous membrane were 76.2%（16/21）、38.1%（8/21）and 9.5%（2/21）respectively.Under TEM,the amyloid deposits have the moderate-density,nonuniform cottony appearance.The amyloid fibrils are relatively straight,nonbranching,without granules and arranged reticulately and about 10 nm in diameter.The percentages of positive amyloid fibrils found in specimens of kidney,adipose tissue of abdominal wall and rectal mucous membrane were 90.5%（19/21）、66.7%（14/21）and 42.9%（9/21） respectively.Conclusion： Electron microscopic examination is an important aid in the ultrapathological diagnosis of systemic amyloidosis,especially in the early stage.The biopsy of both adipose tissue of abdominal wall and rectal mucous membrane is useful and safe in the diagnosis of systemic amyloidosis as well.