The silver impregnation stain is a key method of identifying basement membranes in human tissue, and its application in renal pathology is nearly universal. Notice in this image (Fig 1) how clearly demonstrating the capillary basement membrane using the silver stain allows one to distinguish cells within the capillary lumens from those “extracapillary” cells which are forming the glomerular crescent. In 1951, David B. Jones, MD, reported the development of a periodic acid silver reaction adapted specifically for the kidney which better highlighted basement membranes (American Journal of Pathology, Dec 1951: 991-1009). Most renal pathologists still rely heavily on the Jones...
- Published: April 11, 2017
- By: Arkana Author
Dr. Amin joined Arkana Laboratories in 2016 after successful completion of fellowships in cardiovascular pathology (2015) and renal pathology (2016) at The Mayo Clinic, Rochester. Dr. Amin is involved with our social media team and produces many of our "Pushing Glass" case presentations. In his free time, Dr. Amin enjoys playing the guitar and spending time with family. Interesting Fact: When Dr. Amin was a kid, he wanted to be an astronomer or a biologist. We’re glad he ultimately decided to pursue renal pathology and glad to have him as a part of the Arkana Laboratories family!
Figure 1: PAS-stained section showing a glomerulus with a membranoproliferative pattern of glomerular injury characterized by mesangial matrix expansion and hypercellularity, associated with endocapillary proliferation, glomerular basement membrane double contour formation and accentuation of the lobular architecture. Furthermore, the capillary loops show frequent, large, PAS-positive pseudothrombi, highly suspicious for cryoglobulinemic glomerulonephritis. Cryoglobulins are circulating immunoglobulins that precipitate at 4°C and redissolve at 37°C. They are classified into three types according to the immunochemical composition of the immunoglobulins. Type I cryoglobulins are composed of a single monoclonal immunoglobulin, usually IgM, and are commonly associated with lymphoproliferative disorders such as Waldenstrom macroglobulinemia,...
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Diffuse and nodular glomerulosclerosis is the classic appearance of diabetic glomerulopathy. Note the variability in mesangial areas in this one glomerulus. Some show only mesangial matrix increase while others demonstrate nodule formation. This section is stained with silver methenamine Masson Trichrome (SMMT). With this stain, the mesangium is black indicating that it is all matrix increase with no immune complex type deposits and no infiltrative processes such as amyloid or the fibrils of fibrillary glomerulopathy among others. (SMMT 400x)
We're at the UAMS KIDNEYCon today! Dr. Shree Sharma is teaching at the renal biopsy session this morning. Illustration by our very own Dr. Steve Bonsib!
Some days you just need a king-size bed all to yourself. That's precisely what Rosie prefers. Rosie belongs to Merri, who leads our billing team in Minnesota.
Granular capillary loop staining for thrombospondin type-1 domain-containing 7A (THSD7A). Our understanding of the pathogenesis of membranous glomerulopathy was transformed with the discovery that most cases of ‘idiopathic’ MN are due to autoantibodies directed against the phospholipase A2 receptor (PLA2R) protein.(1) More recently, thrombospondin type-1 domain-containing 7A (THSD7A) protein was described as a second antigenic target of autoantibodies in this disease.(2) Recent reports have implicated malignancy as the underlying etiology in some cases of THSD7A-associated MN.(3-5) 1. Beck LH, Bonegio RG, Lambeau G, et al. M-type phospholipase A2 receptor as target antigen in idiopathic membranous nephropathy. N Engl J Med...
- Published: April 5, 2017
- By: Arkana Author
Before the daily case conference, you can often find one of our physicians having a teaching session around our multi-head scope. We enjoyed having PGY-4 resident Dr. Marjorie David over the past two weeks!
A very common vascular histologic finding in patients with hypertensive nephrosclerosis is arteriosclerosis. In advanced lesions, such as this example, there is prominent intimal fibrosis with narrowing of the vessel lumen. The replacement of smooth muscle cells in the tunica media by fibrous tissue is thought to result from collagen and elastic tissue synthesis by myointimal cells. The degree of intimal fibrosis is thought to be more closely associated with elevated blood pressure than the degree of hyaline arteriolosclerosis.