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Archive: May 2018

Twitter Poll (May 30, 2018)

cholesterol emboli
ANSWER: C The kidney is the most common organ affected by cholesterol emboli in about 75% of the cases, followed by skin (35-70%), spleen (30-55%), lower gastrointestinal tract (18-48%), eyes (6-25%) and other organs such as brain, thyroid and adrenals (4-20%).   REFERENCES: Fries C, Roos M, Gaspert A, Vogt P, Salomon F, Wüthrich RP, Vavricka SR, Fehr T.  Atheroembolic disease--a frequently missed diagnosis: results of a 12-year matched-pair autopsy study. Medicine (Baltimore). 2010 Mar;89(2):126-32. doi: 10.1097/MD.0b013e3181d5eb39. Scolari, Francesco; Ravani, Pietro. Atheroembolic renal disease. The Lancet;  Vol. 375, Iss. 9726,  (May 8-May 14, 2010): 1650-60. Scolari F, Tardanico R, Zani R, Pola A, Viola BF, Movilli E, Maiorca R. Cholesterol crystal embolism: A...

IgA Nephropathy Oxford Scoring

IgA Nephropathy Oxford classification and scoring
The IgA nephropathy Oxford Classification was first published in 2009 by a working group of nephrologists and renal pathologists representing the Renal Pathology Society and International IgA Nephropathy Network. The lesions currently scored include mesangial hypercellularity, endocapillary hypercellularity, segmental sclerosis, tubular atrophy/interstitial fibrosis, and cellular/fibrocellular crescent formation. Two of these lesions, crescent formation (A) and mesangial hypercellularity (B), are shown here.  For the purposes of the Oxford classification, mesangial hypercellularity is defined as >3 mesangial cell nuclei in a mesangial area not adjacent to the vascular pole (in sections cut to 3-micron thickness).

Evaluating Eosin-Stained Frozen Section Slides Using Fluorescence Microscopy

fluorescence microscopy
As published decades ago by Bonsib et al. (see reference), fluorescence microscopy of eosin-stained frozen section slides can be a valuable tool in providing diagnostic clues in kidney biopsies.  The fluorescent properties of eosin dye allow for nice visualization of glomerular capillary and larger vascular basement membranes.  Consequently, various disease processes which disrupt these structures can often be detected using eosin-stained frozen section slides.  The presence of glomerular fibrin, for example, is easy to recognize using this method (see the image showing fibrinogen staining), and indicates a disease process causing glomerular capillary rupture, such as ANCA-related or immune complex-mediated glomerulonephritis. ...

Bile Stained Calcium Oxalate Crystals

stained calcium deposits
A renal biopsy was performed on this 75-year-old female who presented with acute liver failure, jaundice and acute renal failure (serum creatinine 6.4 mg/dl). The predominant biopsy findings are those of acute tubular injury with scattered translucent crystals which show a fan-like morphology (Fig 1) and birefringence upon polarization (Fig 2), consistent with calcium oxalate crystals. Due to the paucity of these crystals, they are favored to represent non-specific deposition in the setting of ongoing tubular injury. Interestingly, the deposited calcium oxalate crystals are bile-stained (Fig 1), a phenomenon which may be seen in the setting of hyperbilirubinemia. Although not...

Pushing Glass (May 25, 2017)

Large B-cell Lymphoma, arkana laboratories, pushing glass
The patient is a 74 year-old female who presents with a sudden rise in creatinine to 5.0. A week ago at her annual physical, her creatinine was 1.0. She presents to the hospital with dehydration and flu like symptoms. She has a history of hypertension and CLL which is followed by oncology. What is the best diagnosis? 1. Acute interstitial nephritis 2. Chronic lymphocytic leukemia 3. Large B-Cell Lymphoma arising from chronic lymphocytic leukemia 4. Acute tubular injury The best answer is (Answer 3) Large B-cell lymphoma arising from chronic lymphocytic leukemia. The biopsy shows a very brisk interstitial infiltrate...

2,8 DHA Crystalline Nephropathy

2,8 DHA Crystalline Nephropathy
The renal biopsy shown here has crystals present within the tubular lumens and cytoplasm with a brownish appearance by H&E (A) that are strongly silver positive on the Jones methenamine silver stain (B). The crystals are birefringent when viewed under polarized light (C).  These findings are characteristic of 2,8 DHA crystal deposition in the kidney resulting from a deficiency of adenine phosphoribosyltransferase. 2,8 dihydroxyadeninuria is an autosomal recessive disease resulting from pathogenic variants in the APRT gene. It is an important disease to recognize as treatment with a low purine diet and allopurinol therapy blocks formation of 2,8 DHA and...


Adenovirus, interstitial hemorrhage and edema
This allograft biopsy shows the characteristic features of adenovirus infection. There is prominent interstitial hemorrhage and edema (Fig. 1), acute tubular injury with viral cytopathic effect and positive immunohistochemical cytoplasmic and nuclear staining for adenoviral antigen (Fig. 2), and foci of tubular necrosis (Fig. 3). The differential diagnosis for this morphology in the transplant setting includes other viral infection (e.g. polyomavirus, CMV, HSV), acute rejection, and drug-related acute interstitial nephritis.

Client Spotlight: Dr. Fidel Barrantes-Ramirez

Dr. Fidel Barrantes-Ramirez, Client spotlight
This month we would like to shine the spotlight on Dr. Fidel Barrantes-Ramirez of Renal Medicine Associates in Albuquerque, NM.   Dr. Fidel Barrantes-Ramirez has special interests in education in kidney disease, health literacy (especially in disadvantaged and minority communities), kidney transplantation outcomes in the elderly and other high-risk groups, and in translational medicine. He believes a well-informed patient always does better. This strong belief led him to author two educational books titled “The First Hundred Days after Kidney Transplant Surgery” and “All About Kidney Transplant. A practical guide for patients, caregivers and providers.” His passion to improve patient education...

Diagnose This (May 21, 2018)

Myoglobin Casts
What is your diagnosis?   ​   ​ ​   ​   ​ ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​ ​   ​ ​   ​ ​   ​ ​     ​   ​   ​ ​...