Long weekend often brings urgent cases. Here is one that was STATed, ended up showing anti-GBM GN. Diffuse crescents (nearly 100%). Linear IgG. #RenalPath

Unfortunately, great cases are almost always not good for the patient. This one has light chain cast nephropathy and deposition dz. PAS-weak casts with cellular reaction. Super bright kappa (lambda neg). Powdery electron-dense material along TBM and mostly mesangium #RenalPath

What do you want to know?.

Not sure why a flood of AA-amyloid from heroin users recently. 3 cases in the last month! IHC is SAA. #RenalPath

Deceased donor biopsy with prominent ATI, some areas of frank tubular necrosis, and collapsing glomerulopathy likely due to ischemia. #RenalPath

Super subtle case of AL-amyloid. I like the combo of IF and LM polarization on Congo red. Very focal amyloid on EM. IF showed rare foci of weak mesangial lambda-restricted staining, correlating to patient's paraproteinemia. #RenalPath

My first cardiac biopsy post. Not sure if #CardiacPath is the right tag. AL-amyloid in heart with kappa restriction (lambda completely negative). Amorphous light pink material in between muscle fibers. Congo red positive.

Urate within the medulla of someone with gout. Crystals washes out with FFPE but happened to catch one on IF frozen sections. Amorphous material can be seen on FFPE sections as well. #RenalPath

AA-amyloid due to IV drug use. We get a good number of these in Northern California, but prevalence depends on location. Possibly related to type of heroin (black tar in particular). #RenalPath

Examples of acute T cell-mediated rejection findings: tubulitis and endotheliitis. This case had a good number of eosinophils, but patient history of non-compliance and endotheliitis (no abx use) strongly favors rejection rather than drug allergy #RenalPath

Nice example of chronic active antibody-mediated rejection with transplant glomerulopathy (and severe arteriolar hyalinosis from years of CNI use). Plenty of double contours and glomerulitis! #RenalPath

I feel like I keep getting great examples of anti-VEGF-induced TMA. Here is one w/ nice EM showing prominent subendothelial widening with flocculent material and new GBM formation. LM with capillary lumen closure, fragmented RBCs, and GBM reduplication. #RenalPath

Older individual with monoclonal gammopathy, proteinuria, worsening renal function. On bx, widespread eosinophilic crystalline inclusions in proximal tubules, kappa-restricted on IF. EM with abundant rhomboid crystals. Light chain proximal tubulopathy. #RenalPath

Good article pointing out some unique findings in such cases:

Another bevacizumab-related (anti-VEGF) glomerulopathy. Many classify this as a "chronic TMA" pattern (note the extensive double contours), although it has it's own unique features that is not typical of TMA, like the hyaline thrombi/aggregates. #RenalPath

Patient with prior Roux-en-Y gastric bypass and now with renal dysfunction. Frequent oxalate crystals. Associated cellular reaction and inflammation as well as some scarring. Widespread tubular injury. Oxalate nephropathy likely 2/2 malabsorption from bypass. #RenalPath

Holy moly! 3 month surveillance bx with abundant polyomavirus (SV40 stain) - easily pvl3. Some ugly looking nuclei with inclusions. I guess that's one reason to do surveillance. Slow graft function but Cr settled ~2 mg/dL. No Cr spike. #RenalPath

A subtle case of amyloid. Congo red under Texas Red filter is great for picking up amyloid. #RenalPath

Patient on bevacizumab (VEGF-inhibitor). Bx with widespread GBM reduplication/complexity. Often referred to as "chronic" TMA pattern of injury. VEGF is needed for endothelial health but this drug disrupts this pathway resulting in a chronic "endotheliopathy". #RenalPath

Nice example of sarcoidosis in kidney bx. Numerous well-formed non-caseating granulomas. Many multinucleated giant cells and some have calcifications. #RenalPath

Just wanted to spread the word that @UCDPath is hiring renal pathologists! Please see link below if interested:.#RenalPath.