Renal Pathology

Introduction:150gm: each kidney1700 liters of blood filtered 180 L of G. filtrate 1.5 L of urine / day.Kidney is a retro-peritoneal organBlood supply: Renal Artery & VeinOne half of kidney is sufficient reservekidney function: Filtration, Excretion, Secretion, Hormone synthesis.

Kidney Location:

Kidney Anatomy:

Renal Pathology OutlineGlomerular diseases: GlomerulonephritisTubular diseases: Acute tubular necrosis interstitial diseases: PyelonephritisDiseases involving blood vessels: NephrosclerosisCystic diseasesTumors

Clinical Syndromes:Nephritic syndrome.Oliguria, Haematuria, Proteinuria, Oedema.Nephrotic syndrome.Gross proteinuria, hyperlipidemia, Acute renal failure Oliguria, loss of Kidney function - within weeksChronic renal failure.Over months and years - Uremia

IntroductionFunctions of the kidney:excretion of waste productsregulation of water/saltmaintenance of acid/base balancesecretion of hormonesDiseases of the kidneyglomerulitubulesinterstitiumvessels

Azotemia: BUN, creatinine Uremia: azotemia + more problems Acute renal failure: oliguria Chronic renal failure: prolonged uremia

Abnormal findings

Glomerular diseasesNephrotic syndromeMinimal change diseaseFocal segmental glomerulosclerosisMembranous nephropathyNephritic syndromePost-infectious GNIgA (immune) nephropathy

Nephrotic SyndromeMassive proteinuriaHypoalbuminemiaEdemaHyperlipidemia

Adults: systemic disease (diabetes)Children: minimal change diseaseCharacterized by loss of foot processesGood prognosisCauses

Minimal change disease

Minimal change diseaseNormal glumerular structure

Normal glomerulusMinimal change disease

Focal Segmental GlomerulosclerosisPrimary or secondarySome (focal) glomeruli show partial (segmental) hyalinizationUnknown pathogenesisPoor prognosis

Focal segmental glomerulosclerosis

Membranous GlomerulonephritisAutoimmune reaction against unknown renal antigenImmune complexesThickened GBMSubepithelial deposits

Membranous glomerulonephritis

Nephritic SyndromeHematuriaOliguria, azotemiaHypertension

Post-infectious GN, IgA nephropathyImmunologically-mediatedCharacterized by proliferative changes and inflammationCauses

Post-Infectious GlomerulonephritisChild after streptococcal throat infectionImmune complexesHypercellular glomeruliSubepithelial humps

Post-infectious glomerulonephritis

IgA NephropathyCommon!Child with hematuria after (URI) Upper Respiratory Infection IgA in mesangiumVariable prognosis

IgA nephropathy

Tubular and interstitial diseasesInflammatory lesionspyelonephritis

PyelonephritisInvasive kidney infectionUsually ascends from UTIFever, flank painOrganisms: E. coli, Proteus

Women, elderlyPatients with catheters or mal-formationsDysuria, frequencyOrganisms: E. coli, ProteusUrinary Tract Infection

Acute pyelonephritis with abscesses

Pyelonephritis

Cellular cast

Chronic pyelonephritis

Drug-Induced Interstitial NephritisAntibiotics, NSAIDSIgE and T-cell-mediated immune reactionFever, eosinophilia, hematuriaPatient usually recoversAnalgesic nephritis is different (bad)

Drug-induced interstitial nephritis

Acute Tubular NecrosisThe most common cause of ARF!Reversible tubular injuryMany causes: ischemic (shock), toxic (drugs)Most patients recover

Acute tubular necrosis

Benign NephrosclerosisFound in patients with benign hypertensionHyaline thickening of arterial wallsLeads to mild functional impairmentRarely fatal

Benign nephrosclerosis

Malignant nephrosclerosisArises in malignant hypertensionHyperplastic vesselsIschemia of kidneyMedical emergency

5% of cases of hypertensionSuper-high blood pressure, encephalopathy, heart abnormalitiesFirst sign often headache, scotomasDecreased blood flow to kidney leads to increased renin, which leads to increased BP!5y survival: 50%Malignant Hypertension

Malignant hypertension

Adult Polycystic Kidney DiseaseAutosomal dominantHuge kidneys full of cystsUsually no symptoms until 30 yearsAssociated with brain aneurysms.

Adult polycystic kidney disease

Childhood Polycystic Kidney DiseaseAutosomal recessiveNumerous small cortical cystsAssociated with liver cystsPatients often die in infancy

Childhood polycystic kidney disease

Medullary Cystic Kidney DiseaseChronic renal failure in childrenComplex inheritanceKidneys contracted, with many cystsProgresses to end-stage renal disease

TumorsRenal cell carcinomaBladder carcinoma

Renal Cell CarcinomaDerived from tubular epitheliumSmoking, hypertension, cadmium exposureHematuria, abdominal mass, flank painIf metastatic, 5y survival = 5%

Renal cell carcinoma

Bladder CarcinomaDerived from transitional epitheliumPresent with painless hematuriaPrognosis depends on grade and depth of invasionOverall 5y survival = 50%

Bladder carcinoma

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