Kidney Flashcards
What are tge 2 major grps of tubulointerstitial kidney dis?
- Ischemic/toxic tubular injury
- Infalmmatory rxn (tubulointerstitial nephritis)
What is the important clinical chracteristic of acute tubular injury or necrosis?
Acute reneal failure
What is the morphological chrcteristic of acute tubular necrosis?
Coagulative necrosis or tubular epithelial cells
What is the primary cause of Acute tubular injury?
Ischemia/Hypoxia or Nephrotoxicity
What are the diff agents ghat can cause nephrotoxocity?
Endogenous agents: hemoglobins, myoglobin, monoclonal light chain, bile/bikirubin
Exogenous: drugs, radioconstrast dyes, heavy metals, organic solvents
What are the main contributors to acute tubular injury?
Tubular epithelial cell injury
Altered blood flow in the vessels of your kidney
What is the morphology of ATI?
Focal tubular pepithelial necrosis
Tubulorrhexis: repture of basement membranes
Occlusion of tubular lumens by casts
What are the 3 stages of a classic case of ATI?
Initiation - rise in BUN, declining GFR
Mainteance: sustained decrease in urine output, hyperkalemia, metabolic acidosis, & other manifesations of uremia
Recovery: steady increase in urine voume, hjypokalemia, normal BUN & creatinine levels
What are groups of inflammatory diseases of tubules & interstitium that manifestest with azotemia?
Tubulointersitial nephritis
What body structure is prominently involved?
Renal pelvis
What are nonbacterial origins of intersitial nephritis?
Drug-induced injury
Metabolic disorders
Physical injury
Viral infections
Immune rxns
How would you describe the clinical onset of acute and chronic tubulointerstitial nephritis?
Acute - rapid onset, infection/allergic drug rxn
CHronic - gradual and slow deterioration of renal function
What is the histological feature of acute tubulointerstitial nephritis?
- interstitial edema
- leukocytic cinfiltraiton
- tubular injury
What are the histological features of chronic htubuloitnerstitial nephritis?
Interstitial FIBROSIS
Mononuclear leukocyte infiltration
Tubular atrophy
What is one of the most common diseases in the kidney that involves the inflammation of the tubules, interstitium, and renal pelvis?
Pyelonephritis
In what conditions are pyelonephritis associated with?
Lower urinary tract infections (UTI)
What are the 2 forms of pyelonephritis?
Acute * chronic pyelonephritis
Acute pyelonephritiss - UTI
Chronic pyelonephritis - obstruction that leads to repeat episodes of acute pyelonephritis
What are the 2 routes by which bacteria can ascend to the kidney?
Acending - bacteria from the lower UT —> kidneys (reflex/obstruction
Hematogenous - seeding of kidneys from distant foci of septicemia/infective endocarditis
What is the cause of acute phyelonephritis?
Ascending lower bacterial UTI
What is a common cause of recurrent UTI in children?
Vesico-ureteral reflux
What is the alternative pathogenesis of acute pyelonephritis?
Obstruction of urine outflow
What is the gross morphology of acute pyelonephritis?
Normal/swollen
Cortical surfaces - multiple, discrete, yellow-white abscesses
What is the histologic morphology of acute pyelonephritis?
Neutrophils within tubular lumen
Suppurative necrosis
Glomeruli are resistant to infection
What are the clincial manifestaions of acute pyelonphritis
Flank pain
Systemic signs: fever & body malaise/
Pus cells in urine
WBC casts
Bladder & urethral irritation: dyuria, frequency, urgency
What rae the diff complications of acute pyelonephritis?
Renal papillary necrosis
Pyonephrosis
Perinephric abscess
What is the type of pyelonephritis complication where it is an infrequent form if pyelonephritis seen in diabetic px, UT obstruction, analgesic abuse & sickle cell anemia?
Renal papillary necrosis
What are the gross & histologic features of renal papillary necrosis?
Gross: gray-white to yellow necrosis at the renal pyramids
Histology: coagulative necrosis surrounded by neutrophilic infiltrate
What kind of pyelonephrotic complication is a result of total or complete obstruction along the ureter? What is a characteristic feature of this condition?
Pyonephrosis
Suppurative exudate ==> pus fills & accumulates in the renal pelvis, calyces, & ureter
What kind of pyelonephrotic complication is an extension of supurative inflammation through the renal capsule? What is its characteristic feature?
Peripnephric abscess
pus in the perinephric tissue
What structures of the kidney are affected by hronic peylonephritis?
Renal parenchyma (calcyes, pelvis) & pelvicalcyeal system
What are the 2 forms of chronic pyelonephritis?
Chronic reflux pyelonephritis
Chronic obstructive pyelonephritis
What is a more common form of chronic pyelonephritis where there is a superimposition of the UTI on congenital vesicoureteral & intrarenal reflex?
Chronic reflux pyelonephritis
- valve does not seal or close completely
- SCARRING of the renal tissue
What is a form of chronic pyelonephritis where there are recurrent episodes of obstruction & infection resutls to renal damage & scarring?
Chronic obstructive pyelonephritis
What is the gross morphology of chronic pyelonephritis?
Gross: irregularly scarred cortical surfaces
Flattening of renal papillae
Blunting & deformed calcyces
What is the histologic morphology of chronic pyelonephritis?
Atrophy of tubules: dilated w/ flattened epithelium
Thyroidization: tubualr lumen is filled wtih pink casts (similar to thryoid colloid)
What is a specific for of pyelonephritis that is associated with infections of Proteus spp & obsutrction?
Xanthogranulomatous pyelonephritis
What are the gross & histological features of xanthogranulomatous pyelonephritis?
Gross: localized mass-like lesion (simialr to renal tumor)
Histo: foamy macrophages interspered with plasma cells & lymphocytes
What are the clinical manifestations of xanthrogranulomaotus pyelonephritis?
Flank pain, pyuria & fever
Mild proteinuria - focal segmental glomerulosclerosis —> ESRD
What are the 2 types of drug-induced tubulointerstitial nephritis?
Acute drug-induecd interstitial nephritis
Chronic interstitial nephritis
What is the 2nd most common cause of AKI after pyelonephritis?
Drug-induced tubulointerstitial nephritis
What are the 3 ways of which kidneys can be injured by toxins and drugs?
- trigger intersitital immunologic rxn
- acute tubular injury
- subclinical but cumulative injury to tubules
What are the adverse rxn of acute drug-induced intersitial neprhitis?
Synthetic penicillins, thiazides, & NSAIDS
What are the clinical manifestations of acute drug-induced interstitial nephritis?
Fever, rash, & renal abnormalities - most common
Manifestations after drug exposure is not depended on dose
What are signs of clinical course of acute intersitital nephritis?
Increase serum creatinine or acute kidney injury w/ oliguria
What is aka analgesic nephropathy where it is caused by excessive chronic intake of NSAIDs, phenacetin-containing analgesics, aspirin, tylenol
CHronic intersitial nephritis
What type of HSN rxn is chronic interistial nephritis?
Type IV
What are the gross morphological changes of chornic interstial nephritis?
Tubulointerstitial nephritis
Renal papillary necrosis (DM & HbS)
What is the clincial course for px suffering from chronic interstitia neprhitis?
Drug withdrawal -> improve renal function
Complicated UTI
Transitional papillary carcinoma of the renal pelvis in some cases
What are other tubulointerstitial diseases?
Urate nephropathy
Hypercalcemia & nephrocalcinosis
Light-chain case nephropathy
Bile cast nephropathy
What are the 3 forms of urate neprhopathy?
Acute uric acid nephropathy
Chronic uric acid nephropathy/Gouty nephropathy
Nephrolithiasis
What happens in acute uric acid nephropathy?
Ppt of uric acid crystals in renal tubules —> nephron obstruction -> ARF
In what population does acute uric acid nephropathy occur?
W/ hematologic malignancies or undergoing chemotherapy
Chemo kills tumor cells —> UA produced from NA breakdown —> INC in collecting tubules
What is aka gouty nephropathy? WHat causes it?
CHronic UA nephropathy
Hyperuricemia —> deposition of urate crystalsi nt he distal convoluted tubule & CTs
What causes nephrocalcinosis?
Uncontrolled chronic hypercalcemia —> Ca stones form in the tubulointerstitium of kidneys —> tubular obstruction & loss of function
What re the earliest functional deficit in nephrocalcinosis?
Inability to contrate urine
Tubular acidosis and salt-losing nephritis
What are significant features of light chain cast nephropathy?
Bence jones proteinuria
Cast nephropathy
What are the histological features of light chain nephropathy?
Eosinophilic cast fractured into plate-like fragments (brittle)
Tubules appear atrophic with flattened epithelium
Fibrotic interstitium, sprinkled sparsely with lymphocytes
What condition is associated with hepatorenal syndrome where there is a marked elevation of seurm blirubibin leading to bile cast formation?
Bile cast nephropathy
How can bile cast contribute to kidney injury?
Bile & bilirubin toxicity
Tubular obstruction
Reversible injury depends on severity & duration of liver dysf
What are the causes of urinary tract obstructions?
INC susceptibility to infection & stone formation —> occurs at any level of the urinary tract
What are the 2 types of urinatry tract obstructions?
Extrinsic lesions - compress the ureter
Intrinsic lesion - in the urinary tract
What is hydronephrosis?
Distention & dilation of renal pelvis & calcyces —> Progressive atrophy of the kidneys due to obstruction of urine outflow
What are some common causes of obsturctive lesion of urinary tract?
Pregnancy
Tumors
Inflammation: prostatis, urethritis, ureteritis, retroperitonea fibrosis
What is the morphology of acute, sudden, or complete urinatry tract obstruction?
Subltle morphological changes
Mild dilation of pelvis
Somes with atrophy of renal parenchyma
What are the 4 types of stones that can cause urolithiasis?
Ca stones
Mg Ammonium PO4 stones
Uric acid stones
Cystine stones
What is the composition of Ca stones and what does it look like in imaging?
Ca oxalate + Ca PO4
Majority of kidney stones
Radiopaque
What type of urolithiasis stone is associated w/ ammonium-producing bacteria (urease pos)leading to alkaline urine? What is the large calculi produces from thsi stone?
Mg ammonium phosphate stones
Forms: Staghorn calculi —> largest calculi
What type of urinary stone is common in those with hyperuricemia, seen in gout, & what does it look like in imaging?
Uric acid stones
Radiolucent
What urinary stone is almost always assoc w/ cystinuria bcos of genetic defects in renal absorption?
Cystine stones
what are the diff factors that affect stone formation?
INC concetration of stone constituents
DEC urine volume
Changes in urinary pH
Presence of bacteria
What is the largest stone formed in the kidney?
Staghorn calculi
What is the gross appearance of staghorn calculi?
Hydronephrosis of kidneys & stones are seen as casts of dilated calyces
What are the specific conditions required to form staghorn calculi?
Urine pH > 7.2 (alkali)
Presence of bacteria in urine (urease pos)
What are the substrates of staghorn calculi?
Mg NH3 PO4 (Struvite) + Carbonate & CaPO4 (apatite) ppt
What are the 5 vascular diseases of the kidneys?
Nephrosclerosis
Renal artery stenosis
Thrombotic microangiopathies
Renal infarcts
Others: atherosclerosis, atheroembolic renal diseaes, sickle cell nephropathy
What renal vascular disorder is strongly associated with hypertension?
Nephrosclerosis
What are the 2 process invaded by nephrosclerosis?
Medial & intimal thickening
Hyalinization of arteriolar wlal
What happens in the medial and intimal thickeing of renal tissue in nephrosclerosis?
Thickening of the BV wall
Narrow lumen
Glomerulosclerosis
What happens if there is hyalization of the arteriolar wall of nephrosclerosis?
INC deposition of basement membrane matrix in the endothlium
What is the gross morphology of nephrosclerosis?
Cortical scarring & shrinking of the kidney —> GRAIN LEATHER APPEARANCE
What is the histologic morphology of nephrosclerosis?
Hyaline arteriosclerosis
- lumen narrowing
- microscopic subcapsular scars
What are the consequences of vascular narrowing in nephrosclerosis?
Tubular atrophy
Interstitial fibrosis
Glomerular alterations
BASICALLY KUMAKAPAL YUNG EPITHELIUM
What are the 3 grps of hypertensives that are highly susceptible to formaiton of nephrosclerosis?
Balcks & african descent
Persons with underlying dis (ie DM)
Persons with malignant hypertension
What causes renal artery stenosis?
INC produciton of renin from ischemic kidneys
What are the common causes of renal artery stenosis?
Narrowing of artery via atheromatous plaque
Fibromuscular dysplasia
What is the most common cause of stenosis?
Narrowing of artery via theromatous plaque
What ist he 2nd most common cause of stenosis?
Fibromuscular dyplasia
What renal vascular disorder forms due to excessive platelet activation depositing thrombi in capillraires & arteroles?
Thrombocytopenia
Microangiopathic hemolytic anemia
What leads to the ingestion of food contaminiated with Shiga-like toxin?
Clasic HUS
What causes the def of TTP?
ADAMTS 13 protease
What is the gross & histological morphology of thrombotic microangiopathy?
Gross:
Acute: patchy or diffuse cortical necrosis & subcapsular etechna
Histo: distended ad occluded glomerular capillaries by thrombi
What is a comon site for development of infarcts?
Renal infarcts
What are often coauses of renal infarcts due to elbolism?
Mural thormbosis in the L atrum due to MI
Less freq: Vegetative endocarditis, aortic aneurystems, & aortic atherosclerosis
What is the gross & histo morphology of renal infatcts?
Gross: White, anemic or pale infarcts that are wedhe-shaped at the apex point towards medula
Histo: coagualtive necrosis
What are other vascular renal disorders?
Atheroembolic renal disease
Atherosclerosiss
Sicke cell nephropathy
What vascular renal dis can lead to HTN in older aging indivisduals?
Atherosclerosis
What are the diff congenital and cystic disesaes of kidneys?
Agenesis of the kidney
Horseshoe kidneys
Cystic disorders of th ekidney
What is bilateral and unilateral agenesis?
Bilateral: stillborn infants who have limb defects, hypoplastic lunfs
Unilateral: solitary kidney enlarges in compensation to hypertrophy
What does a horseshoe kidney look like?
Fusion of upper and lower pole of the kidney
What are the significance of cystic disorders of the kidney?
Heterogenous
Represent diagnost problems
Acute polycystic kidney disease —> major chause of CKD
confused with malignant disorders
What are the different benign neoplasms of the kidney?
Oncocytoma
Renal papillary adenoma
Angiomyolipoma
What is oncocytoma and its histological features?
Arises fro intercalated cells of collecting ducts
Large eosinophilic cells —> small round benign appearing nuclei
What are the gross & histological morphologies of renal papillary adenoma?
Gross: small, discrete nodules arising from the renal tubular epithelium
Histology: Papillomatous structures lined by regular unform small epithelial cells
What benign kidney neoplasm consists of BVs, smooth muscles & fat? WHere does it originate?
Angiomyolipoma
Perivascular epithelioid cells
In what condition is angiomyolipoma seen?
Tuberous sclerosis —> mutations in TSC1 or TSC2
What are the diff malignant neoplasms of the kidney?
Renal cell carcinoma
Urothelial (transitional) renal carcinomas
What is the most important risk factor in the development of renal cell carcinoma?
Tobacco smoking
This cancer is sporadic
What malignant neoplasm of the kidney is common in children?
Nephroblastoma or WIlms tumor
What is a protein found in renal cell carcinoma that is a product of VHL gene, a tumor suppressor?
Von Hippel-Linday protein —> found in chromosome 3p
What is the use of VHL protein?
Inhibits hypoxia inducible genes involved in angiogenesis —> VEGF, TGF-a, GLUT-1
What is the result of loss of VHL?
Tumor angiogenesis, tumor cell proliferation, and epithelial cell proliferation
What are the diff forms of renal cell carcinoma?
Clear cell type
Papillary carcinoma
Chromophobe
What is the most common histologic variant of renal cell carcinoma that has tumor cells with clear or granular cytoplasm?
Clear cell type
What is the cause of clear cell type of renal cell carcinoma?
Proximal convoluted tubular
Unilateral and solitary
What are the gross & histological morphology of clear cellt type of renal cell carcinoma?
Gross: bright yellow-gray to white spherical masses
Histology: tumor cells have round/polygonal shape w/ clear to granular cytoplasm rich in glycogen and lipid
What type of renal cell carcinoma arises from the DISTAL convuluted tubule & appears multifocal & bilateral?
Papillary carcinoma
What is the chromosomal abnormality of papillary carcinoma?
Trisomies 7 &17 + loss of Y in male px in the sporadic form
What are the gross and histological features of papillary carcinoma?
Gross: hemorrhagic w/ necrotic fat surface —> surrounds border fo tumor —> fibrous pseudocapsule
Histo: Cuboidal cells arranged in papillary formaiton within the papillae
What type of renal cell carcinom has multiple losses of entire chromosomes? From where does it arise?
Chromophobe
Intercalated cells of the collecting ducts
What are the gross & histo features of chromophobe?
Gross: well-circumstribed solid beige or light brown fat surface
Histo: pale eosinophilic cells often with perinuclear halo
What are the clinical features of RCC? Which organ is it prevalent?
Paraneoplatic syndrome —> extra-renal manifesations
Prevalent in the lungs & bones
What type of malignant neoplasm of the kidney is morphoogically identical to transitional cell carcinoma of the bladder?
Urothelial (transitional) renal carcinomas
What are the clinical manifestations of urothelial renal carcinoma?
Obstructive symptoms of fragmentation of tumor
Noticeable hematuria
Where does urothelial renal carcnoma arise from?
Intercalated cells of collecting ducts
What are the gross & histo features of urothelial renal cacinoma?
Gross: exophytic ball0-like masses in the renal pelvis & present as obstructive lesions
Histo: >10 cell layers of neopaltic urothelial cells lining the papillae
