The Kidney Flashcards
Most common cause of nephritic syndrome in children LM: diffuse hypercellularity (almost, if not all glomeruli); EM: subepithelial humps on GBM; IF: granular deposits of IgG and complement within the capillary walls mesangium
Acute Postinfectious (Poststreptococcal) Glomerulonephritis (PSAGN)
- Hematuria (with dysmorphic RBCs and red cell casts indicating glomerular pathology); 2. Oliguria and azotemia; and 3. Hypertension
Nephritic syndrome
Type of RPGN associated with anti-GBM antibodies; associated with Goodpasture syndrome (glomerular and pulmonary involvement); uninvolved segments shows no proliferation; EM: ruptures in the GBM; IF: linear IgG and C3 deposits along the GBM
RPGN Type I
Syndrome of progressive loss of renal function, characterized by nephritic syndrome often with severe oliguria; histologic hallmark is presence of crescents, thus crescentic GN
Rapidly progressing glomerulonephritis
Type of RPGN associated with immune complex deposition; usually a secondary event of immune complex-mediated nephritides; uninvolved segment shows immune complex deposition; EM: lumpy bumpy appearance of GBM (due to deposits); IF: granular deposition of Ig and complement in GBM
RPGN Type II
Type of RPGN associated with ANCA; sometimes a component of ANCA vasculitides (Microscopic polyangiitis and Wegener granulomatosis); uninvolved segments shows no proliferation; EM: no detectable deposits; IF: negative for Ig and complement
RPGN Type III
An important cause of ESRD; grossly, kidneys are symmetrically contracted, surfaces are red-brown and diffusely granular; histologically, glomeruli are obliterated with marked interstitial fibrosis.
Chronic glomerulonephritis
Most common cause of nephrotic syndrome in children; responsive to corticosteroids. LM: none; EM: uniform and diffuse effacement of foot processes of the podocytes
Minimal change disease/Lipoid nephrosis
- Massive proteinuria (3.5g/dL; 2. Hypoalbuminemia (<3g/dL); 3. Generalized edema; 4. Hyperlipidemia and lipiduria
Nephrotic syndrome
Most common cause of nephrotic syndrome in adults; involves only some glomeruli (focal), and only a part of glomerulus (segmental) is affected; associated with HIV and heroin abuse. LM: increased mesangial matrix, obliterated capillary lumina, and deposition effacement of foot processes of hyaline masses (hyalinosis) and lipid droplets. IF: nonspecific trapping of immunoglobulins, usually IgM, and complement in the areas of hyalinosis.
Focal segmental glomerulosclerosis (FSGS)
Associated with infections (HBV, Syphilis, Schistosomiasis, Malaria), Malignant solid tumors (lung and colon), SLE, Gold and Mercury, and drugs (Penicillamine, Captopril, NSAIDs); LM: diffuse thickening of the capillary wall; EM: subepithelial deposits along the GBM (spike and dome appearance); effacement of foot processes; IF: granular deposits of immunoglobulins and complement along the GBM.
Membranous nephropathy
Associated with HBV, HCV, SLE, and infected AV shunts; LM: Thickened split GBM (Tram track appearance); EM: subendothelial electron-dense deposits; IF: Irregular granular C3 deposits, with IgG and early complement components (C1q and C4)
Membranoproliferative glomerulonephritis (MPGN) Type I
Formerly called MPGN Type II; fundamental abnormality is excessive complement activation; LM: Thickened split GBM (Tram track appearance); EM: lamina densa and glomerular capillary wall transformed into irregular, ribbon-like, extremely electron-dense structure; IF: Irregular chunky and segmental linear foci of C3 deposits in GBM and mesangium, without IgG and early complement components (C1q and C4)
Dense deposit disease
One of the most common causes of recurrent microscopic or gross hematuria; most common glomerular disease revealed by renal biopsy worldwide. LM: mesangial widening and segmental inflammation; EM: mesangial electron-dense deposits; IF: mesangial deposition of IgA, often with C3 and properdin and smaller amounts of IgG or IgM
IgA nephropathy (Berger disease)
Note: Berger disease and Henoch-Schonlein purpura have the same renal manifestations and morphology, but HSP involves systemic deposition of IgA, has extrarenal symptoms
Nephritis associated with hearing and visual defects; defect in Type IV collagen synthesis; X-linked dominant pattern of inheritance; LM: glomerulosclerosis, vascular sclerosis, tubular atrophy, and interstitial fibrosis; EM: thin GBM (early); irregular foci of GBM thickening or attenuation (late); basket-weave appearance
Alport syndrome
Clinicopathologic entity characterized clinically by acute renal failure and often, but not invariably, morphologic evidence of tubular injury, in the form of necrosis of tubular epithelial cells; has two forms: ischemic and toxic, which vary in terms of affected segments of the nephron and distribution of necrosis.
Acute tubular injury/necrosis
Most common cause of acute kidney injury; a common suppurative inflammation of the kidney and renal pelvis caused by bacterial infection, either by hematogenous spread or through ascending infection (more common and more important mode); principal causes are Gram-negative enteric rods; grossly, there is discrete, yellowish, raised abscesses grossly apparent on the renal surface; histologically, there is liquefactive necrosis with abscess formation within the renal parenchyma.
Acute pyelonephritis
Hallmark of this disease is scarring involving the pelvis or calyces, or both, leading to papillary blunting and marked calyceal deformities; an important cause of chronic kidney disease; forms include: reflux nephropathy (more common), and chronic obstructive pyelonephritis.
Chronic pyelonephritis
Second most common cause of acute kidney injury; T-cell mediated immune reaction of the kidneys to an offending agent, characterized by interstitial inflammation, with abundant eosinophils and edema.
Drug-induced interstitial nephritis
Form of nephrosclerosis associated with essential hypertension; histologically, hyaline arteriolosclerosis; renal insufficiency is uncommon except in patients of African descent, severe HPN, and other diseases e.g. DM.
Nephrosclerosis
Form of nephrosclerosis associated with malignant hypertension; histologically, hyperplastic nephrosclerosis and fibrinoid necrosis.
Malignant nephrosclerosis
Most common causes of renal artery stenosis.
Atherosclerosis and fibromuscular dysplasia
Nephron segments most susceptible to ischemia, and therefore, most affected in ischemic ATN.
Short; straight segments of PT and AL LOH
Autosomal dominant; kidneys are enlarged, composed solely of cysts without intervening parenchyma; cysts are filled with clear or turbid fluid; cysts may arise at any level of the nephron, with variable, often atrophic lining; pathology is defective gene PKD1, which codes for polycystin-1; a protein that is involved in cell-cell or cell-matrix adhesion; most common cause of death: CAD or HHD (40%).
Adult Polycystic Kidney Disease (ADPKD)
Autosomal recessive; numerous small cysts in the cortex and medulla, giving the kidney a “sponge-like” appearance; cysts have uniform cuboidal epithelium; associated with multiple cysts in the liver; pathology is defective PKHD1, which codes for fibrocystin; a protein found in cilia in tubular epithelial cells.
Childhood Polycystic Kidney Disease (ARPKD)
Most common composition of kidney stones.
Calcium oxalate and/or Calcium phosphate (80%)
Most important cause of kidney stone formation.
Supersaturation
Kidney stones occurring in patients with alkaline urine due to UTI, particularly Proteus vulgaris and staphylococci; most common composition of staghorn calculi.
Struvite (Magnesium ammonium phosphate);
Kidney stones seen in patients with gout and leukemias; urine pH is decreased; radiolucent.
Uric acid stones
Kidney stones associated with a defect in the renal transport of certain amino acids; forms in acidic urine.
Cystine stones
Tumors derived from renal tubular epithelium, located primarily at the cortex; with three common forms, clear cell, papillary renal cell and chromophobe carcinomas; most common primary malignant tumor of the kidney.
Renal cell carcinoma (RCC)
Most important risk factor for renal cell carcinoma.
Smoking
Most common form (70-80%) of renal cell carcinoma and associated with homozygous loss of the VHL tumor suppressor gene; thought to arise from proximal tubule cells; usually solitary and large, spherical masses reaching up to 15 cm in diameter; cut surface shows yellow orange to gray-white masses, with prominent areas of cystic softening and hemorrhage; cells appear vacuolated or may be solid; often invades the renal vein.
Clear cell RCC
Accounts for 10-15% of cases of RCC; throught to arise from distal tubule cells; characterized by varying degrees of papilla formation with fibrovascular cores; cells have clear to pink cytoplasm; associated with increased activity of MET oncogene; tends to be bilateral.
Papillary RCC
Accounts for 5% of cases of RCC; thought to arise from intercalated cells of collecting ducts; grossly tan-brown; microscopically, cells have clear, flocculent cytoplasm with very prominent, distinct cell membranes; nuclei surrounded by halos of cleared cytoplasm.
Chromophobe RCC
Most common site of metastases of RCC.
Lungs (>50%), followed by bones (33%)
