Renal Pathology Flashcards
Light/Immunoflourescence/Electron Microscopy Findings in Minimal Change Disease
Only EM finding: foot processes (podocyte) effacement
Disease: Associated w/ dense subendothelial immune complex deposits, granular IF, “tram-track” apparance
Type 1 Membranoproliferative Glomerulonephritis (MGN) – nephritic/nephrotic; GBM splitting by mesangial ingrowth
Disease: associated w/ C3 nephritic factor, intramembranouse dense deposits
Type 2 Membranoproliferative Glomerulonephritis (MGN) – C3NF stabilizes C3 convertase (C3bBb) –> low serum C3
Average adult kidney weight
150g
What cell is the major glomerular barrier to protein loss in the urine?
Podocytes
This congenital renal disease is associated with increased risk later inlife for developing 2ndary FSGS due to overwork of the nephron
Unilateral renal agenesis –> overwork of nephron –> progressive glomerular sclerosis
Disease: X-linked dominant type IV collagen mutation –> thinning and splitting of GBM; EM: “basket-weave” appearance
Alport Syndrome – Nephritic Syndrome; “can’t see (retinopathy, lens dislocation), can’t pee (glomerulonephritis), can’t hear a bee (sensorineural deafness)
Markedly reduced intrauterine urine production leads to ___
Potter sequence = Low urine production –> oligohydraminos –> compression –> low-set ears, small receding chin, beak-like nose, abnormally bent lower extremities
Renal hypoplasia definition and frequent association
Histologically normal kidney w/ less than 6 lobes; frequently oligomeganephronia (enlarged glomeruli)
Horshoe kidney associated pathologies
- Renal infection (Pyelonephritis) – ureter obstruction
- Renal stones
- Hydronephrosis – ureter obstruction
Congenital Disease: Histo: undifferentiated tubules and ducts, mantles of undifferentiated mesenchyme (SmM and cartilage)
Renal Dysplasia – aplastic, multicystic, diffuse cystic, obstructive forms
MCC of an abdominal mass in newborns?
Unilateral multicystic renal dysplasia = renal enlargement by multiple cysts –> irregular mass
What part of the nephron does it affect?
- -Adult AD PKD
- -Autosomal Recessive PKD
–AD PKD = Anywhere – Glomerulus, PT, DT, CD
–AR PKD = Collecting Duct
Earliest, most common presentation of AD PKD
Hypertension
MCC of Neophrotic syndrome in:
- -Caucasian Adults
- -American Blacks
- -Children
Caucasian Adults = Membranous Nephropathy
American Blacks = FGSG
Children = MCD
Disease: EM: “spike and dome” appearance, subepithelial deposits
Membranouse Nepropathy = nephrotic presentation of SLE, diffuse capillary and GBM thickening, MCC in Caucasian adults
MCC of 2ndary nephrotic syndrome and end-stage renal disease in US
Diabetes –> Diabetic Glomerulonephropathy = Eosinophilic nodular glomerulosclerosis: mesangial expansion, GBM thickening
Disease: Associated w/ Kimmelstiel-Wilson lesions
Diabetic Glomerulonephropathy
Disease: Associated w/ effacement of podocyte foot processes in EM, but normal glomerulus in light microscopy and IF studies.
Minimal Change Disease – selective proteinuria (albumin)
–Corticosteroids –> remission w/ intermittent relapse
Disease: Associated with VHL tumor suppressor gene deletion on chromosome 3
Renal Cell Carcinoma
Disease: Risk factors include Schistosoma haematobium infection (Middle ease), chronic cystitis, smoking, chronic nephrolithiasis
SCC of Bladder = chronic irritation –> squamous metaplasia –> dysplasia –> SCC
—Presents with painless hematuria
Disease: Associated w/ deletion of WT1 tumor suppressor gene
WAGR syndrome = Wilms tumor, Aniridia, Genital abnormalities, mental and motor Retardation
Disease: Associated w/ mutations of WT1 tumor suppressor gene
Denys-Drash syndrome = Wilms tumor, progressive renal (glomerular) disease, male pseudohermaphroditism
Disease: Associated w/ mutations in WT2 gene cluster, particularly IGF-2
Beckwith-Wiedmann syndrome = Wilms tumor, neonatal hypoglycemia, muscular hemihypertrophy, organomegaly (including tongue)
Disease: Classically presents w/ painless hematuria, multifocal “field defect” (recurring) tumors, risk factors include: naphthylamine, azo dyes (hair salon), cyclophosphamide or phnacetin
Urothelial Carcinoma
Characteristics of Flat vs. Papillary pathway of Urothelial Carcinoma
Flat = develops as high grade-flat tumor, early p53 mutations Papillary = develops as low-grade papillary tumor, progresses to high grade, no early p53 mutations
Disease: arises from a urachal remnant, cystitis glandularis, or exstrophy
Urinary adenocarcinoma (usually bladder)
- -Urachal remnant = at dome of bladdre
- -Cystitis glandularis = columnar metaplasia
- -Exstrophy = congenital failure failure to form caudal portion of anterior abdominal and bladder walls
Disease: Hamartoma of blood vessels, smooth muscle, and adipose tissue
Angiomyolipoma – increased frequency in Tuberous Sclerosis
Where does Renal Cell Carcinoma arise?
Epithelial cells of proximal kidney tubules
RCC can cause a varicocele on which side?
Left – L spermatic vein leads drains into L renal artery (can be blocked in RCC)
–R spermatic vein drains directly into IVC
This type of stone is treated with HCTz
Calcium oxalate/phosphate
Kidney stones of these 2 substances can form staghorn calculi
Ammonium magnesium phosphate = classical staghorn
Cystine
Infection w/ urease positive organisms (Proteus, Klebsiella) can lead to this kind of nephrolithiasis
Ammonium magnesium phosphate – forms in alkaline urine
This kind of kidney stone can’t be seen in X-ray
Uric acid
Gene products affected in AD PKD vs. AR PKD
AD PKD = polycystin 1, 2 = Ca signalling normally inhibiting tubular growth
AR PKD = fibrocystin = regular cell differentiation, proliferation and adhesion in collecting ducts
What congenital kidney disease is associated w/ berry aneurysms (family hx of death my aneurysm), hepatic cysts, and mitral valve prolapse?
AD PKD
Disease: Autosomal dominant defect leading to parenchymal fibrosis and shrunken kidney
Medullary Cystic Kidney Disease = cysts in medullary collecting ducts –> worsening renal failure
Which 2 parts of the nephron are most susceptible to ischemic damage?
- Proximal tubule
2. Medullary segment of TAL
Acute Tubular Necrosis causes what acid/base change?
- Increased Anion gap metabolic acidosis (decreased excretion of organic acids (K-H antiport)
- Hyperkalemia (decreased renal excretion)
Disease: IF microscopy shows linear pattern
Goodpasture syndrome (Type 2 hypersensitivity) = anti-basement membrane (type IV collagen) antibody; associated w/ HLA-DRB1
What diseases are associated with granular pattern in IF microscopy?
PSGN or Diffuse proliferative glomerulonephritis = immune complex deposition
In what disease does IgA immune complex deposit in mesangium of glomeruli?
IgA Nephropathy (Berger Disease) = most common nephropathy worldwide ---Childhood presentation of hematuria w/ RBC casts
What nephrotic syndrome has good response to steroids?
Minimal Change disease (MCD)
—Poor response = FSGS, Membranous nephropathy, MPGN
What is the first change in the kidney in Diabetes Mellitus?
Nonenzymatic glycosylation of vascular basement membrane –> hyaline arteriolosclerosis (affecting efferents more than afferents) –> hyperfiltration injury –> microalbuminemia
What is ‘thyroidization’ of the kidney and when do you see it?
Atrophic tubules containing eosinophilic proteinaceous material resembling thyroid follicles
- –Seen in Chronic Pyelonephritis
- –May have waxy casts in urine
What is the most common cause of acute intrarenal azotemia?
Acute Tubular necrosis
What kind of acute renal failure?
Urine osm = 500+
FENa = less than 1%
BUN/Cr = 20+
Pre-renal azotemia = low renal blood flow –> low GFR
–> more reabsorption of fluid and BUN –> high ratio, low FENa
What kind of acute renal failure?
Urine osm = less than 350
FENa = 2%+
BUN/Cr = less than 15
Intrinsic renal failure = Usually Acute Tubular Necrosis = patchy necrosis –> debris –> obstruction –> low GFR –> impaired BUN and Na reabsorption;
–classic brown granular/epithelial casts
Urine osm, FENa, and BUN/Cr changes in Early vs. Long-standing Post-renal azotemia
Post-renal azotemia
- -Early stage obstruction = decreased outflow –> forces BUN back into blood (high BUN/Cr ratio), normal tubular function (FENa less than 1%, high urine Osm)
- -Long-standing obstruction = tubular damage –> impaired BUN and Na reabsorption (low BUN/Cr ratio, high FENa), inability to concentrate urine (low Urine osm)
When do you see fatty casts (“oval fat bodies”)?
Nephrotic syndrome, where lipids are passes along with protein
—“Maltese cross” sign
When do you see WBC vs RBC casts?
RBC Casts = glomerulonephritis, malignant HTN
WBC Casts = tubulointerstitial inflammation, acute pyelonephritis, transplant rejection
3 Types of Urinary Incontinence and their causes
- Stress Incontinence = urethral hypermobility or intrinsic sphincter deficiency; sneezing, lifting
- Urgency Incontinence = overactive bladder; detrusor instability
- Overflow Incontinence = incomplete emptying; detrusor underactivity
