Flashcards in 17 - Renal Pathology III Deck (53):
What diseases cause asymptomatic isolated hematuria?
- IgA nephropathy(Berger Disease)
- Alport syndrome
- Thin GBM disease
Describe IgA nephropathy
- Most common type of primary glomerulonephritis worldwide
- Affects children and young adults
- Quite common in young adults, but NOT in African-Americans
- Causes recurrent hematuria
What will you see in a urinalysis of IgA nephropathy?
What will you see in an LM, IF and EM of IgA nephropathy?
NEED TO KNOW ****
- LM: Mesangial proliferation
- IF: Mesangial IgA
- EM: Mesangial deposits
Describe mesengial proliferation
Mesangial hypercellularity of more than 3 cells per mesangial region
Describe alport syndrome
- Alport syndrome is a defect of the glomerular basement membrane due to mutation in the gene encoding for the alpha-5 chain of collagen type IV
What are the clinical manifestations of alport syndrome?
- Sensorineural deafness
- X-linked dominant inheritance
- Affects males, females are carriers
- Presents with microscopic hematuria
- Progresses to renal failure
- Proteinuria is a sign of progression
What are the key lesions of alport syndrome?
- GBM thickening, splitting and lamination
- "Basket-weave" pattern
***KNOW BASKET WEAVE***
AB --> Alport = Basket
Describe thin GBM disease
- Benign familial (hereditary) hematuria
- About HALF of the GBM is as uniformly thin as it should be
What will you see on the LM, IF and EM or thin GBM disease?
LM = normal
IF = negative
EM = thin GBM
What are the secondary causes of glomerulonephropathies?
- SLE (lupus)
Describe lupus nephritis (SLE)
- Kidney is a major target of disease
- Granular immune complexes deposit in the glomerulus
What are the types of immune complexes that deposit in lupus nephritis?
Granular immune complex deposition of IgG, IgA, IgM, C3, C4
This is the ONLY glomerular disease with ALL immunoglobin deposition *****
What does diabetes cause in the kindey?
AKA diabetic nephropathy
How does diabetic nephropathy present?
Can present as proteinuria, nephrotic syndrome or chronic renal failure
Describe amyloidosis with kindney involvement
Amyloid gets "trapped" in:
- blood vessels
What does amyloid deposition cause?
- Usually the glomerular basement membrane becomes too "leaky" to proteins and the patient gets "nephrotic syndrome"
- Kidneys appear as a big pale "waxy" kidney
What will amyloidosis appear like under polarized light?
NEED TO KNOW *****
"Apple green birefringence"
Know this word by word ***
This apple green birefrigence appearance will be visible when stained with CONGO RED and seen under polarized light *****
Describe acute tubular necrosis (ANT)?
- Destruction of renal TUBULAR epithelium
- Loss of renal function
- 50% of ACUTE renal failure
This is NOT in the glomerulus, in the TUBULAR epithelium ***
What are the two types of acute tubular necrosis?
Either due to lack of blood flow or toxins
What types of nephrotoxic substances cause acute tubular necrosis (ANT)?
- Drugs (aminoglycosides, amphotericin B, gentamycin)
- Heavy metals (mercury)
- Organic solvents (carbon tetrachloride from dry cleaners)
- Radiocontrast dyes (contrast)
- Myoglobin (rhabdomyolysis in heat stroke)
What are the pathologic changes seen in acute tubular necrosis (ANT)?
- Dilated tubules with flattened epithelium
- Necrotic debris in tubules
Describe acute interstitial nephritis
A drug induced hypersensitivity reaction
What can cause acute interstitial nephritis?
- Synthetic penicillins
- Thiazide diuretics
What happens 2 weeks after taking the drug?
- Acute renal failure (oligouria + increased Cr)
What are the different types of pyelonephritis?
- Ascending = MOST COMMON*** (reflux or obstruction)
- Hematogenous is also possible (from blood)
Ascending means urethra --> bladder --> ureters --> kidney --> pelvis
What is the most common pathogen of pyelonephritis?
E coli ***
This is only for when it comes from ascending, not blood
What will you see in an acute case pylonephritis?
What will you see in chronic pyelonephritis?
Lymphocytes and scars (fibrosis)
What is the most common pathogen of pyelonephritis from the blood?
Hematogenous is also called "descending"
Can cause the formation of an abscess on the kidney (more commonly in hematogenous than ascending)
Describe acute pyelonephritis
- Caused by infections of the pelvicalyceal system and renal parenchyma
- May present with pain in the costo-vertebral angle plus other signs of infecitons
- Diagnosis - pus (WBC) casts, urine culture
MUST have costo-vertebral angle pain and fever
What are the key lesions in acute pyelonephritis?
Neutrophilic infiltrates and neutrophil casts in tubules are characteristic
Describe chronic pyelonephritis
- May have insidious onset or a history of recurrent acute pyelonephritis
- Gradual loss of renal function
- Results in scarred kidney with chronic inflammation
What can cause chronic pyelonephritis?
- Obstruction (congenital or acquired)
- Instrumentation (catheter)
- Vesicoureteral reflux
- More common in females
- Previous lesions
- Immunosuppression or immunodeficiency
What is the hallmark of chronic pyelonephritis grossly?
Pitting geographic "scars"
What is the microscopic hallmark of chronic pyelonephritis
**** Commonly Tested ****
- Scarred renal cortex with destruction of architecture
- The atrophic tubules look like the thyroid gland architecture, so it is sometimes called "thyroidization"
- Fibrosis occurs due to chronic inflammatory infiltrate
What are the KEY lesions of chronic pyelonephritis?
- Scarred kidneys, chronic inflammation
- Severe tubular atrophy, thyroidization of the kidney
What are the types of benign renal tumors?
- Adenoma (papillary)
What are the types of malignant renal tumors?
Renal Cell Carcinoma
- Clear cell
Describe a papillary adenoma
- Always within the cortex
- AKA “cortical adenoma”
Describe an angiomyolipoma
- Association with tuberous sclerosis
- Mental retardation
- Multisystem hamartomas
- Consists of smooth muscle (myo), fat (lipo) and thick walled vessels (angio)
What are the risk factors for renal cell carcinoma?
- Chronic renal failure and acquired cystic renal disease ***
- Unopposed estrogen therapy
- Heavy metals
What are the symptoms of renal cell carcinoma?
- Hematuria (50-60%) ***
- Abdominal mass (25-40%) ***
- Flank pain (35-40%)
- Hypertension (20-40%)
- Weight loss (30-35%)
- Fever (5-15%)
What does renal cell carcinoma strongly tend to invade?
STRONGLY tend to invade the renal VEIN early
What are the three histotypes of renal cell carcinoma?
- Clear cell
- Chromophobe RRC
Describe the clear cell histotype of renal cell carcinoma
Clear cell RCC
- Loss of tumor suppressor gene VHL
- Gross appearance is yellow/orange
Describe the papillary (chromophil) histotype of renal cell carcinoma
Papillary (chromophil) RCC
- Activation of pro-oncongene gene MET
Describe the chromophobe histotype of renal cell carcinoma
- Loss of multiple chromosomes resulting in hypodiploidy
- Prognosis is the best among 3 histotypes
Describe the microscopic image of papillary (chromophil) RRC
Papillary structures many of which enclose clusters of foamy macrophages
Tumor cells have abundant eosinophilic cytoplasm and mildly atypical nuclei
Describe the difference between clear cell and papillary cell RRC microscopically
- abundant clear cytoplasm
- abundant capillaries
- eosinophilic (pink) cytoplasm
- sparse capillaries
Describe the renal morbidities of dialysis patients
- Approximately 35% of patients on chronic dialysis develop acquired cystic disease in their native kidneys.
- Renal cell carcinoma develops in approximately 6% of these patients.
Describe the associated syndrome of VHL
Von Hippel-Lindau syndrome (VHL)
- Cavernous hemangiomas in cerebellum, brain stem & eye
- These patients have a remarkably high incidence of RCC
- Associated with germline mutations of the VHL tumor suppressor gene on chromosome 3