CRP-20

CRP-20

Clinical History

The patient is a 24 year old while male. Systemic sclerosis. Presented with acute renal failure and hypertension and is now on dialysis. Rule out scleroderma renal crisis. BUN 22, creatinine 4.3; normal complements. Urinalysis shows 3+ protein and 3+ blood.

Gross Description

Received in transport media are two cores measuring 11 and 14 mm in length and 2 mm in diameter. Three 1-mm pieces are submitted for EM, and the remaining tissue is bisected and equally divided for immunofluorescence and light microscopy.

Pathology

Case CRP-020 Trichrome

Microscopic Description, Immunofluorescence, and Electron Microscopy

Microscopic Description

Light Microscopy

Sections contain two fragments of renal cortex. There are about forty-five glomeruli per level. All of the glomeruli are similar and show severe ischemic atrophy. They appear rather solid and hypocellular, and the mesangium has a peculiar fibrillar appearance. There is focal mesangiolysis with red cell fragments in the mesangium. The silver stain shows marked thickening of the glomerular basement membranes and numerous double contours along the capillary loops. A number of the glomeruli contain fibrin thrombi and fibrinoid necrosis in the capillary loops. PASH and trichrome stains show diffuse mild interstitial fibrosis and focal chronic tubular atrophy. There is also acute tubular injury, manifested by irregular dilatation, epithelial simplification and sloughing. There is mild interstitial inflammation, and occasional examples of tubulitis are noted. The most striking change in the biopsy is in the vessels. Virtually every arterial vessel, including arterioles, interlobular arteries, and small arcuate arteries, is affected. There is mucoid intimal thickening, and large masses of fibrin are present under the endothelium as well as in the lumina. There is also infiltration of thickened intima by red blood cells, many of which are fragmented. However, there is essentially no inflammation associated with these vascular lesions.

Immunofluorescence

There are twenty-eight glomeruli in the sections. There is 2+ focal and segmental mesangial staining for IgM, Clq and C3. There is no glomerular staining for IgG, IgA, albumin or light chains. There is C3 staining in the vessels. There is no staining of the tubular basement membranes.

Electron Microscopy

Three thick sections containing a total of twelve glomeruli are available. Ultrastructural examination reveals markedly increased mesangial matrix. The glomerular basement membranes are severely thickened and wrinkled. The subendothelial space is markedly expanded and contains loose granular material. The visceral cell foot processes are completely effaced, and many of the capillary loops are partially or completely denuded. No immune complex deposits are identified. Several vessels are completely occluded by masses of fibrin.

Diagnosis and Comments

Kidney, needle biopsy - Scleroderma

These features are typical of scleroderma, and in conjunction with the clinical history are entirely consistent with scleroderma renal crisis. The presence of thrombosis in virtually all the vessels, coupled with secondary severe ischemic changes in the glomeruli and tubules, suggests that extensive scarring is inevitable. Significant recovery of renal function is very unlikely.

Renal failure is the severe reduction of renal function and often leads to reduced urinary output.

Blood urea nitrogen (BUN) is used as a measure of the glomerular filtration rate and is increased in renal failure.