Kuang-Yu Jen, MD, PhD

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

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