Renal Pathology Flashcards
Learn about renal pathology
Describe renal cell carcinoma under— Incidence, Risk Factors, Types, Pathogenesis and Classification.
- RCC is a malignant tumor of kidney
- It presents at 60-70 years. Male: Female= 2:1
- Risk Factors:
- Tobacco
- Obesity
- Exposure to petroleum products, asbestos
- Hypertension
- CKD, ESRD
- Tuberous Sclerosis
- Types: Maybe be Sporadic (96%) or Familial. Familial cases are parts of 4 syndromes:
- VHL syndrome - VHL gene LOF chromosome 3p - Clear cell RCC
- Hereditary Leiomyomatosis and RCC Syndrome - FH gene mutation - Papillary RCC
- Hereditary Papillary RCC - MET gene mutation (encoding HGF) - Papillary RCC
- Birt-Hogg-Dube (BHD) Syndrome - BHD gene mutation encoding Folliculin - Chromophobe RCC
-Classification: Based on genetic, cytogenetic and microscopical features: Clear Cell RCC, Papillary carcinoma, Chromophobe carcinoma, Collecting Duct Carcinoma
Describe the morphological features of Clear Cell Carcinoma.
CLEAR CELL CARCINOMA
Gross: Solitary, well circumscribed.
Origin: PCT
Microscopy:
1. Cells may be arranged in the form of tubules or trabeculae
2. Tumor cells are round/polygonal with clear cytoplasm and centrally placed nuclei
3. The cytoplasm is clear due to glycogen and lipids which get washed during processing of tissue section
4. Glycogen and lipids can be stained by PAS and Oil Red O
5. Stroma consists of delicate septa with thin walled blood vessels
Morphological features of Papillary RCC and Chromophobe RCC.
PAPILLARY RCC Origin: Multifocal (PCT/DCT) Microscopy: 1. Tumor cells arranged in Papillary formation 2. Foamy macrophages may be seen in the papillae 3. Psamomma bodies 4. Stroma is scanty but highly vascular IHC Marker: Cytokeratin 7
CHROMOPHOBE RCC
Origin: Intercalated cells of collecting duct
Microscopy:
1. Pale eosinophilic cells with raisin like nuclei
2. Perinuclear halo
3. Prominent cell membrane
Special stain: Hale’s Colloidal Iron
Congenital anomalies associated with ADPKD
- Cysts in spleen, pancreas, lungs
- Intracranial Berry aneurysm
- Mitral valve prolapse and other valvular anomalies
ADPKD - definition , Pathogenesis, morphology, clinical features.
It is a hereditary disorder characterized by multiple expanding cysts in both kidneys, which ultimately destroy the renal parenchyma and cause renal failure.
Pathogenesis:
1) Mutation of PKD1 gene (85% cases) - On Chromosome 16p - Encodes Polycystin 1
2) Mutation of PKD2 gene - On chromosome 4q - Encodes Polycystin 2
Mutations in these two proteins — altered mechanosensation by tubular cilia and altered Calcium flux— Altered tububular epithelial growth and differention — abnormal ECM interactions, abnormal cell proliferation and fluid secretion — cyst formation — cyst causes glomerular and vascular damage and causes interstitial inflammation
Morphology:
Gross- Enormous size (4kg), external surface seems only composed of cysts with no parenchyma
Microscopy-
1) Functioning nephrons are present between the cysts
2) Cysts filled with serous fluid, sometimes haemorrhagic fluid
3) Arise from different parts of the tubules and thus have different lining epithelium
Clinical features:
- flank pain
- bilateral abdominal masses
- renal colic (due to blood clots in urine)
- hypertension
- renal failure (when sufficient no. of neohrons are destroyed
Autosomal recessive polycystic kidney disease- Genetics, morphology, clinical features.
Genetics: Mutation in PKHD1 gene on chromosome 6p- encodes fibrocystin
Fibrocystin is also located on primary cilium of tubular cells.
Morphology
Gross: Enlarged kidneys, smooth external surface. Cut section shows numerous cystsbinncortex and medulla so kidney appears sponge-like
Microscopy- 1) Cylindrical dilations of collecting tubules are seen (less commonly saccular)
2) They have uniform cuboidal epithelial lining as they all arise from collecting tubules.
Clinical features:
1) All patients also have cysts in the liver.
2) Those who survive infancy develop congenital hepatic fibrosis- bland periportal fibrosis and
proliferation of biliary ductules
3) Older children may develop portal hypertension with splenomegaly
What is akanthosis?
Thickening of thr epithelium
Wilms Tumor - Syndromes associated.
1) WAGR Syndrome - Mutation in Chromosome 11p13 where WT1 gene is located
2) Denys Drash Syndrome - Mutation in WT1 gene
3) Beckwith Wiedemann Syndrome - Mutation in WT2 gene
In 95% cases, Wilm’s tumor is sporadic. In remaining 5% cases it is associated with above 3 syndromes.
Wilms Tumor morphology.
Gross: Large, round, well circumscribed
Cut section shows a tan grey color
Microscopy: 3 components
1) Immature epithelial component: Cells form small tubules or rosettes
2) Immature stromal component: Consist of fibroblast like spindle cells
3) Blastemal component: Small dark blue, round to oval, primitive cells with scanty cytoplasm. Arranged in nests/sheets/trabeculae.
Wilms Tumor: clinical presentation and spread.
Usually affects children 2-5 yrs old
1) Abdominal mass that can cross the midline
2) Abdominal pain
3) Hematuria
4) May present as intestinal obstruction and lung metastasis.
Spread
1) Local- Perirenal soft tissue
2) Hematogenous: Lung, liver
3) Lymphatics: Regional lymph nodes
What is pyelonephritis? What are the types and causes
Inflammatory condition of the kidney affecting the tubules, interstitium and the renal pelvis.
Two types:
1) Acute: Due to infection
2) Chronic: Though infection plays a major role, other factors such as VUR and obstruction are also involved in the pathogenesis
Cause of acute pyelonephritis
1) Bacterial
2) Viral
3) Fungal
4) Parasitic
What is pyelonephritis? What are the types and causes
Inflammatory condition of the kidney affecting the tubules, interstitium and the renal pelvis.
Two types:
1) Acute: Due to infection
2) Chronic: Though infection plays a major role, other factors such as VUR and obstruction are also involved in the pathogenesis
Cause of acute pyelonephritis
1) Bacterial
2) Viral
3) Fungal
4) Parasitic
Morphology of acute pyelonephritis.
Gross:
- Focal abscesses seen on the subcapsular surface of kidneys : appear grey white areas
- Calyces and pelvis are hyperemic and covered with purulent exudate
Microscopy
1) Interstitium: Neutrophilic inflammatory infiltrate
2) Tubules: Intratubular aggregate of neutrophils and abscess formation—> Tubular atrophy
3) Glomeruli: Mostly unaffected
4) Calyces and pelvis: Acute inflammatory infiltrate
Chronic pyelonephritis: Definition, types.
Chronic inflammation of the kidney involving the tubules, interstitium and renal pelvis.
Types:
1) Reflux nephropathy : Superimposed infection on a VUR and intrarenal reflux. Maybe uni/bi- fibrosis and scarring
2) Chronic obstructive pyelonephritis: Recurrent infections superimposed on obstructive lesion
Types of renal stones.
4 types
1) Calcium stones
2) Struvite stones
3) Cysteine stone
4) Urate stones
