Department of Radiology, Mayo Clinic, 200 First St SE, Rochester, MN 55905, USA.
Radiographics. 2011 Oct;31(6):1569-82. doi: 10.1148/rg.316115519.
Amyloidosis is a heterogeneous group of disorders and may be classified as systemic or localized on the basis of the distribution of amyloid deposition. Infrequently, the urinary tract and supporting retroperitoneum may be involved, and the imaging findings are nonspecific and diverse. Localized amyloidosis usually involves the bladder and often mimics malignancy. Less frequently, the ureter, renal pelvis, and urethra are involved. The most common findings of amyloid deposition are focal or diffuse wall thickening in the urinary tract with intramural calcification that often results in ureteral obstruction. When the renal parenchyma is involved, patients generally develop nephrotic-range proteinuria, and the kidneys appear atrophic with cortical thinning. In systemic amyloidosis, amyloid may infiltrate the retroperitoneal and pelvic soft tissues, encasing the urinary tract, with diffuse soft-tissue thickening and slowly progressive calcification. In both localized and systemic amyloidosis, amyloid lesions are characteristically hypointense at T2-weighted magnetic resonance imaging. Because myeloma or lymphoma is often present with systemic amyloidosis, biopsy is necessary to diagnose the condition. Amyloid lymphadenopathy characteristically appears as nodal enlargement with calcification and low attenuation at computed tomography. Radiologists should be familiar with the imaging features of amyloidosis that, in the appropriate clinical context, may indicate the diagnosis.
淀粉样变性是一组异质性疾病，可以根据淀粉样物质沉积的分布进行系统性或局限性分类。偶尔，尿路和支持它的腹膜后间隙可能会受到累及，影像学表现是非特异性和多样化的。局限性淀粉样变性通常累及膀胱，且常类似于恶性肿瘤。输尿管、肾盂和尿道受累较少见。淀粉样物质沉积的最常见表现是尿路的局灶性或弥漫性壁增厚，伴壁内钙化，常导致输尿管梗阻。当肾实质受累时，患者通常会出现肾病范围的蛋白尿，肾脏出现萎缩，皮质变薄。在系统性淀粉样变性中，淀粉样物质可能会浸润腹膜后和骨盆软组织，包裹尿路，导致弥漫性软组织增厚和缓慢进展性钙化。在局限性和系统性淀粉样变性中，淀粉样物质病变在 T2 加权磁共振成像上呈特征性低信号。由于骨髓瘤或淋巴瘤常伴有系统性淀粉样变性，因此需要进行活检以明确诊断。淀粉样淋巴结病的特征是淋巴结肿大伴钙化和 CT 上的低衰减。放射科医生应该熟悉淀粉样变性的影像学特征，这些特征在适当的临床背景下可能提示诊断。
