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Renaut Body

Renaut body, neuro notes, muscle biopsy, neuropathology
Figure 1: Cross section of sural nerve with Renaut Body (arrow) and background moderate diffuse axonopathic process.  Plastic embedded thick section stained with Toluidine blue, original magnification x400. A 65-year-old female presents with complaint of numbness and tingling in her hands and feet with gradual progressive onset. She is diabetic, and clinical work-up shows no positive autoantibodies. Nerve conduction studies show electrodiagnostic findings of a mixed sensory and motor polyneuropathy.  The clinical differential diagnosis includes diabetic polyneuropathy versus chronic inflammatory demyelinating polyradiculoneuropathy (CIDP).  A sural nerve biopsy is performed.  What is the structure indicated by the arrow in this image...

Twitter Poll (February 3, 2021)

SAP, Serum amyloid protein P, twitter poll, renal pathology, arkana laboratories
Answer: C) SAP Serum amyloid protein P (SAP) has been found to be a highly sensitive and specific marker for the diagnosis of Membranous-Like Glomerulopathy with Masked IgG Kappa Deposits. Of note, while these cases show light chain restriction by immunofluorescence, most patients do not have evidence of an underlying paraprotein. For further information about this interesting entity, please see the following references. References Larsen CP, Sharma SG, Caza TN, et al. Serum amyloid P deposition is a sensitive and specific feature of membranous-like glomerulopathy with masked IgG kappa deposits. Kidney Int 2020 Mar;97(3): 602-608. Larsen CP, et al. Membranous-like...

Arkana Live – February 2021

february, Renal Intratubular Casts, january, december, Endocarditis-Related Glomerulonephritis, Infection-Related Glomerulonephritis, Light Microscopy, august, FSGS, september, october, July, Arkana Live, arkana laboratories
Did you enjoy the last Arkana Live? Don't miss part 2! Join us on February 13th as Dr. Zeljko Dvanajscak will be continuing his session on casts.   Register here: Arkana Live February 2021  

Denervation MCQ

Denervation MCQ, Denervation type changes, neuropathology, neuro notes, arkana laboratories
Frozen section of skeletal muscle stained with nonspecific esterase. (Original magnification:  100x) A 45-year old male firefighter with diabetes mellitus presents with chief complaint of lower back pain, right proximal thigh weakness, and minimally elevated CPK. Spine imaging shows multi-level degenerative joint disease and moderate spondylolisthesis.  A skeletal muscle biopsy is obtained from the patient’s right thigh.  What findings are seen in the esterase stained frozen section shown of the right rectus femoris?   Answer: The findings are those of mild active/ongoing denervation-type change. The muscle fibers of interest are variably atrophic and acutely angulated with a suggestion of a...

Episode 1: Representativeness

Using Therapy to Guide a Diagnosis, knowing the therapy, Severity of Change, principles of pathology, representativeness, arkana labs, renal path
🚨New Series Alert! 🚨   Dr. Silva offers his advice as a leader in kidney pathology along with pearls that all pathologists, nephrologists, and physicians should know in his new series, Principles of Pathology. Tune in each week for a new episode!  

Diagnose This (January 25, 2021)

Asteroid Body, Sarcoidosis, renal pathology, arkana laboratories, pathology of the kidney
What is the name of the finding at the end of the arrow and what condition is it classically associated with?       ​ ​   ​   ​ ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​ ​...

Satellite Cells

Satellite Cells, Neuro Notes, neuropathology, arkana laboratories
An adult patient with proximal muscle weakness presents with CK 4400 and skeletal muscle biopsy of the thigh shows frequent regenerating and necrotic muscle fibers. In this electron micrograph of skeletal muscle, what are the structures indicated by the black arrows? Satellite cells are a normal population of undifferentiated cells within a skeletal muscle fiber that is capable of differentiating into myoblasts (i.e. stem cell-like properties), hence providing a source to produce new myotubes, as well as regeneration after injury (i.e. necrotizing myopathy).  The figure demonstrates satellite cells between the basal lamina and plasma membrane.  One of the satellite cells...