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Reference: Boils CL, Nasr SH, Walker PD, Couser WG, Larsen CP. Update on endocarditis-associated glomerulonephritis. Kidney Int. 2015 Jun;87(6):1241-9. #TeachingPoints #kidneypath #renal #pathology

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considering the potential adverse outcome if a patient with endocarditis was mistakenly treated for ANCA-associated glomerulonephritis with cytotoxic agents in lieu of antibiotics.

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glomerulonephritis without endocapillary proliferation. Further, 28% of the patients with endocarditis-associated glomerulonephritis had positive serologic studies for ANCA. Therefore, it is important to maintain a high index of suspicion for infective endocarditis-associated glomerulonephritis...

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Crescentic glomerulonephritis is most commonly an autoimmune-related glomerulonephritis (e.g. ANCA, anti-GBM disease, lupus nephritis). However, a recent case series (reference below) found that more than 50% of cases of endocarditis-associated glomerulonephritis show a crescentic pattern of...

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Of note, myoglobin casts and hemoglobin casts cannot always be distinguished from each other on morphology alone. And, in most cases immunoperoxidase staining for hemoglobin and myoglobin can easily facilitate differentiation. #DiagnoseThis #renalpath #kidneypath #pathology #rena

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Arkana Labs @arkanalabs.bsky.social · 08/10/2026

The photomicrograph shows beaded, lightly pigmented casts within tubules that are consistent with myoglobin casts and below, an immunoperoxidase stain for myoglobin confirms this diagnosis.

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There’s no better place to gain exposure to renal pathology. At Arkana, we offer a mid-career subspecialization that gives you the opportunity to deepen your expertise and explore the world of renal pathology. Learn more: bit.ly/4zf1MkG #RenalPathology #Pathology #PathTwitter

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Arkana Labs @arkanalabs.bsky.social · 07/10/2026

Here's today's #eyeSCANdy! This scan is showing intestinal giardia in a renal biopsy. Photo courtesy of Dr. Stephen Bonsib. #renal #pathology #kidneypath

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The images show lymphocytic tubulitis as well as an eosinophil-rich interstitial inflammatory infiltrate. These findings are consistent with acute interstitial nephritis... #renalpath #kidneypath #pathology #renal #pathtwitter

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The crystals are characteristically black by Jones methenamine silver stain(C). #TeachingPoints #kidneypath #renal #pathology

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The morphologic findings of 2,8-DHA crystals on renal biopsy are shown here. Small, needle-shaped, brownish crystals are present within the tubular lumens and epithelial cells (A and D) that are highly birefringent when examined under polarized light (B).

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2,8-DHA nephropathy has also been reported to recur in the renal allograft resulting in rapid allograft failure. Prompt and accurate diagnosis of this disorder is important so that treatment through pharmacologic inhibition of xanthine dehydrogenase can be initiated.

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The clinical presentation of this often-misdiagnosed disease is widely variable among patients homozygous for APRT mutations, ranging from asymptomatic in some to reddish-brown diaper stains in infants to recurrent nephrolithiasis, and even CKD in the absence of nephrolithiasis.

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Arkana Labs @arkanalabs.bsky.social · 30/09/2026

Adenine phosphoribosyl transferase (APRT) deficiency results from an autosomal recessive enzyme defect of purine metabolism and leads to 2,8-dihydroxyadenine (2,8-DHA) crystalline nephropathy.

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Today’s #eyeSCANdy! Acellular SEM of membranous GN, stage IV. Note the distinct craters and circular orifices of the incompletely bridged reticular BM. Inset: TEM showing thickened GBM with discrete crater (arrow) and partially bridged and resorbed deposits. Photo courtesy of Dr. Stephen Bonsib.

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In the native kindney, this finding is most commonly seen in cryoglobulinemic vasculitis (which was the case for this patient). The differential diagnosis would include other forms of vasculitis such as ANCA-associated diseases. #TeachingPoints #kidneypath #renal #pathology

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rheumatoid factor. While the intima is inflamed and edematous, the media is relatively intact without inflammation or necrosis. Intimal arteritis is a pattern of vascular inflammation most commonly encountered in the transplant setting where it represents a rejection process.

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This photomicrograph shows an artery with intimal edema and inflammation in a renal biopsy from a 56 year old male with renal failure and nephrotic-range proteinuria. The patient's serologic work-up revealed evidence of an HCV infection and a positive.. #TeachingPoints #kidneypath #renal #pathology

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While this patient was not obese nor had premature delivery at birth, the biopsy showed around 70% global sclerosis and a second diagnosis of hyperfiltration injury was rendered, likely due to acquired reduced nephron mass secondary to glomerular/nephron loss from the underlying Fabry disease.

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Interestingly, the perihilar focal segmental glomerulosclerosis identified here was present in numerous glomeruli as well as marked glomerulomegaly. #renalpath #kidneypath #pathology #renal #pathtwitter

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As suspected, extensive accumulation of intra-podocyte myeloid bodies (a.k.a. zebra bodies, myelinosomes) are seen in all podocyte cell bodies examined (see image below). And, subsequent testing revealed Fabry disease in this patient. #renalpath #kidneypath #pathology #renal #pathtwitter

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And, while myeloid bodies can be seen in patients on chloroquine or hydroxychloroquine therapy, they are typically sparse or focal in these settings. #renalpath #kidneypath #pathology #renal #pathtwitter

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However, if you look closely you will notice that the podocyte cell bodies are very large and vacuolated. This finding is uncommon and is typically seen in the setting of Fabry disease (and usually very difficult to appreciate, unlike in this example).

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Arkana Labs @arkanalabs.bsky.social · 23/09/2026

This photomicrograph of a Jones silver stain is interesting in that it shows two findings. First, at 10 o’clock an area of hyalinosis at the perihilar region is present and compatible with perihilar focal segmental glomerulosclerosis. #renalpath #kidneypath #pathology #renal #pathtwitter

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Here is today’s #eyeSCANdy! Acellular scanning EM from a biopsy with membranous glomerulonephritis showing depressions and larger "craters" along the subepithelial aspect of the basement membrane. Photo courtesy of Dr. Stephen Bonsib. #renal #pathology #kidneypath

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Arkana Labs @arkanalabs.bsky.social · 21/09/2026

The immunofluorescence study is negative. What is your diagnosis? #DiagnoseThis #nephtwitter #pathtwitter #renal #kidneypath

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Arkana Labs @arkanalabs.bsky.social · 16/09/2026

Here is today’s #eyeSCANdy! Acellular scanning EM showing "craters" at high power on the subepithelial aspect of the glomerular basement membranes from a biopsy with membranous glomerulonephritis Photo courtesy of Dr. Stephen Bonsib. #renal #pathology #kidneypath

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Arkana Labs @arkanalabs.bsky.social · 09/09/2026

What enzyme is deficient in this patient’s disease? A. Acid alpha-glucosidase B. Glycogen phosphorylase C. Glucose-6-phosphate translocase D. Myophosphorylase #NeuroNotes #neuropath #pathology #neuromuscularpath #PathX #PathTwitter

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Arkana Labs @arkanalabs.bsky.social · 09/09/2026

Clinical History: The patient is a young child a year prior to the current biopsy to have compound heterozygous GAA variants. Hex4 levels were initially elevated but since initiating enzyme replacement therapy, the levels have dropped within normal limits.

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Arkana Labs @arkanalabs.bsky.social · 09/09/2026

Here is today’s #eyeSCANdy! Acellular scanning EM of a glomerulus with membranous glomerulonephritis, stage II showing diffuse reticular appearance of GBM elaboration. Photo courtesy of Dr. Stephen Bonsib. #renal #pathology #kidneypath

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Arkana Labs @arkanalabs.bsky.social · 03/09/2026

“A”, “B”, “C” and “D” are all part of a Schwann cell subunit. “A” is a denervated non-myelinating Schwann cell profile; “B” is the nucleus of a non-myelinating Schwann cell; “C” is a collagen pocket

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Arkana Labs @arkanalabs.bsky.social · 03/09/2026

The correct answer is D! The small diameter unmyelinated axon marked by “D” shows microtubules and intermediate filaments within its axoplasm. These are best seen on high magnification images.

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Arkana Labs @arkanalabs.bsky.social · 03/09/2026

Dr. Rhee gave 70-80 hours a week to her last job, and watched it quietly take a toll on her life and health. She got to a point where she was questioning whether she could stay in medicine at all. Learn more : www.arkanalabs.com/careers/renal-pa…

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Arkana Labs @arkanalabs.bsky.social · 02/09/2026

In the supplied medium and high magnification images from electron microscopy, which of the labeled structures represents an intact unmyelinated small diameter axon? A. B. C. D. #NeuroNotes #neuropath #pathology #neuromuscularpath

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Arkana Labs @arkanalabs.bsky.social · 02/09/2026

Clinical History: This 40-year-old patient presented with progressive neuropathic symptoms affecting their distal lower extremities and hands. A sural nerve biopsy was performed.

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- diagnosis of C3 glomerulopathy is rendered. Reference Link: www.ncbi.nlm.nih.gov/pubmed/24429... #renalpath #kidneypath #pathology #renal #pathtwitter

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- immunofluorescence. Because of this and other masked lesions (such as some cryoglobulinemic GNs and paraprotein-related GNs) predilection for staining with C3 only by routine immunofluorescence, we suggest paraffin retrieved immunofluorescence be done on all C3 only staining cases before a -

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Membranous-Like glomerulopathy with Masked IgG Kappa Deposits is a relatively new diagnostic category that typically affects young females, often displaying vague autoimmune symptomatology, and can easily be mistaken for C3 glomerulopathy due to its masked staining qualities on routine paraffin -

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