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Archive: September 2020

Diabetic Polyneuropathy

Diabetic Polyneuropathy, Hyaline thickening, neuro notes, arkana laboratories, muscle biopsy
This is an interesting common vascular finding in a sural nerve biopsy taken from an adult diabetic patient with paresthesias.  This photomicrograph shows hyaline thickening of an endoneurial blood vessel wall (black arrow, right of center) due to reduplication of perivascular basement membrane material and plump endothelial cells with associated narrowing of the vascular lumina.  These vascular changes are commonly seen in the setting of diabetic polyneuropathy and contribute to the myelinated axonal loss observed (i.e. axonopathic process) (toluidine blue stained thick section prepared from glutaraldehyde-fixed Epon resin-embedded tissue, 1000x oil immersion).

Diagnose This (September 21 ,2020)

Endothelialitis, arkana laboratories, diagnose this, renal pathology, kidney pathology
Q:What is this finding and what is the significance in the transplant setting?   The light microscopic image depicts an artery with endothelialitis characterized by mononuclear cell inflammation under the arterial intima. This finding is compatible with a diagnosis of acute vascular rejection, grade IIA. Importantly, vascular rejection need not be seen in association with interstitial inflammation or tubulitis and for scoring purposes, the worst artery present (i.e. showing the most severe arteritis) dictates the overall v- score. Finally, vascular rejection can be seen not only in pure T-cell mediated rejection but can also be seen with acute antibody-mediated rejection.

Perifascicular Atrophy in Dermatomyositis

Perifascicular Atrophy, neuro notes, Arkana Laboratories, muscle biopsy
What histologic finding is observed in this case?     Answer:  Perifascicular Atrophy in Dermatomyositis   This case shows an acquired inflammatory myopathy with well-developed perifascicular atrophy.  Generally speaking, acquired inflammatory myopathies may be morphologically grouped into three categories: Polymyositis, Dermatomyositis, and Inclusion Body Myositis.  The classification of acquired inflammatory myopathies has undergone recent refinement, and additional entities show characteristic morphologic and clinical features (see Pestronk reference).  In the realm of acquired inflammatory myopathies, perifascicular atrophy is characteristic of dermatomyositis. The finding of skin rash in a characteristic distribution on physical exam is helpful, but is not always present (i.e. involvement...

Twitter Poll (September 16, 2020)

Fibrillary glomerulonephritis, arkana laboratories, twitter poll
Answer: C Fibrillary glomerulonephritis is a rare disease affecting less than 1% of all native kidney biopsies and is due to fibrillary deposits of immunoglobulin that by electron microscopy are randomly arranged fibrils of approximately 18-20 nm in diameter. Clinically patients will present with proteinuria and hematuria. Histologically it can show several patterns within glomeruli including mesangial proliferative, membranoproliferative, or even a crescentic pattern of glomerular injury. Positive staining with the DNAJB9 stain is extremely useful in identifying this disease as it is around 98% sensitive and 99% specific for Fibrillary GN. Associations with Fibrillary GN include autoimmune disease, infection...

New Neuropathology Series: Neuro Notes

neuro notes, neuropathology, arkana laboratories
Introducing Neuro Notes!🚨   This new series by our neuropathologists, Dr. Wilson and Dr. Mrachek, will be highlighting cases, diagnosing neuropathological diseases, and making other observations in their unique neuropathology practice.   Below are ATPase enzyme histochemical stains from a skeletal muscle biopsy:   Image 1- pH 9.6 (Type II dark, Type I pale) Image 2- pH 4.6 (Type I dark, Type 2A pale, Type 2B intermediate) Image 3- pH 4.3 (Type I dark, Type II pale).  

Our Friend and Colleague: Robin Ollis

Robin Ollis, Arkana Employee, Arkana Laboratories
We lost a dear friend and colleague this week. Yesterday we said goodbye to Robin Ollis, our Assistant Lead for Electron Microscopy. Robin joined Arkana in 2011 and since then, he has not only served thousands of patients, but he also has trained, coached, and championed dozens of teammates. He was incredibly kind and such a joyful person to work with and we are honored to have been able to call him "one of us" for as long as we did. He will be incredibly missed. 

Diagnose This (August 31 ,2020)

Alport Syndrome, COL4A5, COL4A3, COL4A4, Alport, X-linked, Hearing loss, GBM multilamellation
Q: What is your diagnosis based on this IF staining pattern in a patient with hematuria and proteinuria?   The immunofluorescence image is that of an Alport panel. The red staining highlights the alpha 2 subunit of collagen type IV while the green staining is that of the alpha 5 subunit of collagen type IV. The image shows segmental loss of the alpha 5 staining of type IV collagen along the glomerular basement membranes compatible with Alport syndrome. Alport syndrome is an inherited disease secondary to mutations in the alpha 3, 4, and 5 subunits of type IV collagen. The...