A Case of Rheumatoid Arthritis Presenting with Renal Thrombotic Microangiopathy Probably due to a Combination of Chronic Tacrolimus Arteriolopathy and Severe Hypertension

Figure 2

Light micrographs of renal tissues. (a) A glomerulus (asterisk) is mildly enlarged, showing focal segmental glomerulosclerosis while another glomerulus exhibits collapsed capillary tuft (arrowhead). Dilated tubules with flattened epithelial cells containing proteinaceous casts are present (arrow) (periodic acid-Schiff stain; original magnification x200). (b) Several glomeruli have collapsed capillary tufts (arrows). There is an extensive striped pattern of interstitial fibrosis and tubular atrophy (Elastica–Masson staining; original magnification x200). (c) A glomerulus is globally sclerotic (asterisk). There is organized thrombus formation within an afferent arteriolar lumen (arrowhead). Concentric intimal hyperplasia of arterioles forming “onion skin” lesion is noted (arrow) (periodic acid-Schiff stain; original magnification x200). (d) Glomerular capillary wall is segmentally thickened showing double contour (arrow) (periodic acid-Schiff stain; original magnification x400). (e) Arteriolar lumina are occluded by fibrous intimal thickening with recanalization. Nodular hyalinosis of arterial walls is noted (arrow) (periodic acid-Schiff stain; original magnification x400). (f) An arteriolar wall shows circumferential and transmural hyalinosis forming peripheral nodules (periodic acid-Schiff stain; original magnification x400).

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