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Archive: September 2018

Twitter Poll (September 26, 2018)

ANSWER: D Hall’s stain is used to confirm the presence of bile casts. This technique uses the oxidizing action of Fouchet’s reagent to convert the bile pigment (bilirubin) into an easily identifiable green color (biliverdin). Bile pigments appear green against a yellow background. The color ranges from olive green to emerald green, depending upon the concentration of bilirubin. REFERENCES: Hall MJ. A staining reaction for bilirubin in sections of tissue. Amer J Clin Path, 1960; 34:313-316. Luna LG. Manual of Histologic Staining Methods of the Armed Forces Institute of Pathology, 3rd ed., McGraw-Hill, N.Y., c. 1968, p.174. van Slambrouck CM,...

A source of myoglobinuria…

The image shows a frozen cross section of skeletal muscle from a patient with rhabdomyolysis, which included the full clinical syndrome of muscle pain, weakness, dark urine, and markedly elevated serum creatine kinase.  The image shows three necrotic fibers engulfed by macrophages (arrow).  So what causes such muscle injury?  The broad differential diagnosis includes trauma, drugs (e.g. statins, alcohol, heroin, cocaine), toxins (e.g. metabolic poisons, animal venom), inflammatory myopathy, immune-mediated necrotizing myopathy (e.g. anti-HMG CoA reductase associated myopathy), infection (e.g. EBV, influenza), paraneoplastic myopathy, and metabolic myopathy (e.g. disorders of glycolysis, lipid metabolism, mitochondria).

Dr. Velez Visit

Dr. Juan Carlos Q Velez stopped by this morning for a visit.  After a quick tour, he spoke to us about Hepatorenal AKI: Hemodynamic and Parenchymal Correlates of Pathogenesis.  After which, he stayed for our daily case conference.  

Arkana Vandal

Our on-call board has been vandalized.  Dr. Larsen can "neither confirm nor deny any allegations," but we have our suspicions...    

Fungus Microabscess

Cortical microabscess formation is a clue to the presence of an infectious organism.  Various bacteria, viruses, fungi, and even parasites may cause similar appearing lesions.  This biopsy is taken from a renal transplant patient with acute kidney injury and microscopic hematuria.  The low-power image shows a densely mixed cellular infiltrate involving the tubulointerstitium (Fig. 1).  Higher magnification shows tubulitis with intratubular leukocytes and rare structures suspicious for fungal elements (Fig. 2).  Gomori methenamine silver staining confirms the presence of budding yeast forms (Fig. 3 arrow) with hyphae and pseudohyphae.  Fungal isolates from urine culture showed colony morphology characteristics consistent with...

Arkana Physician Spotlight: Dr. Silva

Dr. Fred Silva joined Arkana Laboratories in 2011 following 12 years of service as the Executive Vice President and Secretary-Treasurer of the United States and Canadian Academy of Pathology. During that time, he also served as Adjunct Professor of Pathology at Emory University in Atlanta, as well as Visiting Clinical Professor at the Medical College of Georgia in Augusta. Dr. Silva received his BS and MD from the University of Oklahoma. He trained at Columbia University College of Physicians and Surgeons in New York City where he also served as Assistant Professor in Surgical and Renal Pathology. In 1980, he...

DNAJB9 helps uncover dual pathology…

This case illustrates the utility of immunohistochemical staining for DNAJB9, a recently described biomarker for fibrillary glomerulopathy (see reference).  The renal biopsy is taken from a 68-year-old man with a history of cirrhosis (cause unknown) who presents with mild microscopic hematuria, non-nephrotic range proteinuria, and chronic renal failure.  Glomeruli show diffuse mild mesangial matrix expansion.  Immunofluorescence shows granular mesangial IgA (2+) and smudgy mesangial and capillary wall IgG (2+) staining.  Electron microscopy (not shown) shows both immune complex-type and fibrillary deposits involving glomerular capillary basement membranes and mesangium.  Immunohistochemical staining for DNAJB9 shows mesangial staining.  Although IgA immunofluorescence staining may...

Not Quite Nodular

This biopsy came from a 70-year-old gentleman with acute renal failure. He had a known history of diabetes, hypertension, and chronic kidney disease.  His baseline serum creatinine is between 1.7 mg/dl and 1.9 mg/dl and was found to be elevated up to 2.9 mg/dl. Proteinuria was quantified as 0.2 g/g on urine protein to creatinine ratio.  Urinalysis showed trace blood and protein.  While processing the clinical information, one has to admit that this clinical presentation is not an unusual one.  A fair number of patients will have a decline in renal function that reflects the reality of an already struggling...

Membranous Glomerulopathy in Obesity-Related Glomerulopathy

The patient is a 57-year-old female, with a history of morbid obesity and persistent mild proteinuria (approximately 1 gm), who now presents with nephrotic syndrome and a UPCR of 10.5 g/g. Renal function is normal with a serum creatinine of 0.5 mg/dl. The biopsy shows marked glomerulomegaly with focal areas of perihilar segmental glomerulosclerosis (Fig 1 and 2). Additionally, the capillary loops appear mildly thickened, with frequent subepithelial fuchsinophilic deposits on trichrome stain and diffuse and global holes and spikes seen on silver stain (Fig 3). Immunofluorescence shows global capillary loop granular staining for IgG, C3, kappa, and lambda (Fig...

Twitter Poll (September 6, 2018)

ANSWER: A - Thick ascending limb of the loops of the Henle THP (aka uromodulin) is an 85 -kDa glycoprotein encoded by the UMOD gene in humans.  It’s involved in the pathogenesis of light chain cast nephropathy, urolithiasis, and tubulointerstitial nephritis, in urothelial cytoprotection against UTIs, and in mutations of the THP gene in FJHN and MCKD2. References: Micanovic R, et al. Tamm-Horsfall Protein Regulates Granulopoiesis and Systemic Neutrophil Homeostasis. J Am Soc Nephrol 2015; 26(9): 2172-2182. Serafini-Cessi F, et al. Tamm-Horsfall glycoprotein: biology and clinical relevance. Am J Kidney Dis 2003; 42: 658-676. Nasr SH, et al. Uromodulin storage...