Tubules- Pathology Flashcards
This is the most common cause of acute renal failure where there is an acute decline in renal fxn often with morphologic evidence of tubular injury.
Acute Kindey Injury (AKI)
What are the 4 causes of AKI?
- Ischemia
- Direct toxic injury
- Acute tubulointerstitial nephritits
- Urinary obstruction
What do u see in the urine in AKI?
Dirty brown granular casts
What happens to the GFR in AKI?
↓ because of an ↑ backpressure from the plug
What 2 segments of the nephron are susceptible to ischemic AKI?
PCT and medullary segment of thick ascending limb.
In ischemic AKI, waht protein is seen in the eosinophilic hyaline casts?
Tamm-Horsfall protein
What area is susceptible to toxic AKI?
PCT
What causes nephrotoxic AKI?
Aminoglycosides, heavy metal (lead, Slayer), myoglobinuria (crush injury), ethylene glycol, radioconstrast, urate (tumor lysis syndrome)
What are the names of the 3 stages for AKI?
Initiation, Maintenance, and recovery
In the initiation phase, what happens the BUN in addition to the slight decline in urine output?
↑ BUN (azotemia)
In the maintenance phase of AKI, there are sustained decreases in urine output, salt and water overload, rising BUN, and what changes in [K] and [H]?
hyperkalemia
metabolic acidosis
What happens to [K] in the recovery phase?
hypokalemia
What is the Tx to AKI?
Dialysis
This is a drug-induced hypersensitivity rxn of the interstitum and tubules, leading to ARF.
Acute interstitial nephritits (AIN)
What are the Sx to AIN?
fever, eosinophilic, rash, renal abnormalities, azotemia
What are the 3 drug classes to cause AIN?
NSAIDs
PCN
Diuretics
Which WBC do u see in the urine in AIN?
Eosinophils
What type of hypersensitivity rxn is AIN?
Type I
Case: pt presents with headache, anemia, GI Sx and HTN. Biopsy shows chronic tubulointerstitial nephritis and renal papillary necrosis. What has this pt been doing to cuase this?
Taking a ton of analgesics
Renal papillary necrosis is a result of what 4 things?
chronic analgesic abuse (phenacetin or ASA use), diabetes mellitus, sickle cell trait or disease, severe acute pyelonephritis
What are the 4 forms of renal injury from NSAID use?
1 hemodynamically induced ARF (↓ prostaglandins)
- acute hypersensitivity interstitial nephritis
- acute interstitial nephritis and minimal-change disease.
- membranous nephropathy
Who is susceptible to acute uric acid nephropathy?
Chemo pts
Who is susceptible to chronic urate nephropathy?
gout pts
What forms in the kidney in chronic urate nephroapthy?
monosodium urate crystals which form a tophus with giant cells and a fibrotic rxn
Nephrocalcinosis is a result of what?
Disorders that are associated with hypercalcemia
Who is at risk for acute phosphate nephropathy?
People drinking that horrible crap b4 a colonoscopy
This is the condition where nonrenal malignant neoplasms (myelomas) cause tubulointerstitial problems from the tumor or the therapy itself.
Light-chain cast nephropathy
What is the main cause of renal dysfxn in Light-chain cast nephropathy?
Bence Jones (light chain) proteinuria
What is the morphology of the masses that fill the tubular lumens in Bence Jones nephropathy?
pink-blue amorphous masses that are surrounded by giant cells
This is sclerosis of renal arterioles from hyaline arteriolosclerosis from extravasation of plasma proteins or medial and intimal thickening as a response to hemodynamic changes
Benign nephrosclerosis
This is when dramatic HTN can cause vascular damage to kidneys, leading to fibrinoid necrosis of arterioles and small arteries. This has onion skinning pattern on exam.
Malignant HTN
This is an uncommon cause of HTN where the renal artery is stenosed, which increases renin (cuz it thinks there is hypotension), and HTN develops
Renal artery stenosis
Why is HTN from renal artery stenosis easy to treat?
Just cut away the stenosed renal artery
These are a group of disorders characterized clinically by microangiopathic hemolytic anemia, thrombocytopenia, and renal failure, and morphologically by thrombotic lesions in capillaries and arterioles in various tissue beds, including those of the kidney
Thrombotic microangiopathies
This microangiopathy is from consuming food with contaminated bacteria producing Shiga-like toxins.
Typical HUS
This microangiopathy is associated with inherited mutations of complement-regulatory proteins or diverse acquired causes of endothelial injury
Atypical HUS
This microangiopathy is associated with inherited or acquired deficiencies of ADAMTS13, which regulates the fxn of von Willebrand Factor (vWF)
TTP
After eating contaminated food, what are the Sx to typical HUS?
start diarrheal and move with a sudden onset of bleeding manifestations (especially hematemesis and melena), severe oliguria, and hematuria.
is atypical HUS easy or hard to treat?
hard
What is the pentad of Sx in TTP?
fever, neurological Sx, microangiopathic hemolytic anemia, thrombocytopenia, and renal failure
What is the Tx of TTP?
This is from autoantibodies against ADAMTS13, so treatment is with immunosuppressive therapy
What morphology of the kidneys shows in the acute stage in the microangiopathies?
patchy or diffuse cortical necrosis and subcapsular petechiae. The glomerular capillaries are occluded by thrombi
Case: pt presents with bilateral ischemic necrosis of the cortical region only. What did the patient just do to cause this?
Have an obsteric emergency (abruption placentae, septic shock, or extensive surgery)
What is the morphology of the kidney in renal infarcts?
Wedge-shaped infarct with ischemic necrosis in many foci
What congential anomaly is incompatible with life?
bilateral agenesis of the kidney
What happens to the other kidney in unilateral agenesis?
Hypertrophy and can develop progressive glomerular sclerosis
This is the failure of kidneys to develop to normal size.
Renal hypoplasia
Is renal hypoplasia typically unilateral or b/l?
unilateral
Are most cases of renal hypoplasia congenital or acquired?
Acquired
This is when the kidneys lie either just above the pelvic brim or sometimes within the pelvis.
Ectopic kidney
What is at risk in an ectopic kidney?
Kinking a ureter
This is the fusion of the upper + lower poles and is the most common renal anomaly.
Horseshoe kidney
This is the condition characterized by the persistence of abnormal structures in the kidney (undiffrentiated mesenchyme, immature CD’s and abnormal lobar organization).
Multicystic renal dysplasia
What is morphology of the kidney in multicystic renal dysplasia?
usually enlarged, extremely irregular + multicystic
This is the inherited disorder where there is bilateral enlargement of the kidneys with cysts in renal cortex and medulla.
PKD
Which form of PKD presents in infants?
AR form
What are the 2 associated with the AR form of PKD?
Congenital hepatic fibrosis and hepatic cysts
What are the Sx to the AR form of PKD?
Worsening renal failure and HTN
Who gets the AD form of PKD?
ADults
What are the Sx to the AD form of PKD?
HTN, hematuria, worsening renal failure
What is the mutated gene in the AD form of PKD?
APKD1 or APKD2
What are the 3 association with the AD form of PKD?
Berry aneurysm (causes death), hepatic cysts, and MVP
“cysts in the liver, cysts in the brain, cysts in the kidney”
This is the inherited AD defect where there are cysts in the medullary collecting ducts.
Medullary cystic kidney disease
What is the morphology of the kidneys in Medullary cystic kidney disease?
parenchymal fibrosis resulting in shrunken kidneys and worsening renal failure
This is the AR condition where there are corticomedullary cysts and shrunken kidneys, and progrssive renal failure beginning in childhood.
Familial juvenile nephronopthisis (FJN)
What are the complications to FJN?
salt wasting, polyuria, growth retardation, and anemia
These are single or multiple cysts in normal-sized kidneys.
Simple cysts
What is the 1 complication to simple cysts?
Microscopic hematuria
Acquired renal cystic disease is from what?
Dialysis
What are the complications to acquired renal cystic disease?
hemorrhage, erythrocytosis, and renal cell carcinoma in the walls of the cyst
If a pt has dilation of the kidney pelvis and atrophy, what is the cause?
Postrenal obstruction
This is the term for the dilation of renal pelvis + calyces associated with progressive atrophy of kidney due to obstruction to the outflow of urine
Hydronephrosis
What are the most common type of stones u see in patients?
Calcium oxalate + Calcium phosphate
Case: pt presents with alkaline urine and a staghorn caliculi. What did she recently have to cause it?
An infection (proteus + klebsiella)
Struvite stones- Mg, Ammonium, phosphate
Who is at risk for uric acid stones?
Gout pts
What do u see on Xray for uric acid stones?
Nothing. Theyre the only 1 that are radiolucent
Who is at risk for cystine stones?
Kids with genetic defects in renal reabsorption problems
Which stones are more hazardous, small or large stones?
Small cuz thye may pass into the ureters and produce colic + obstruction.
This is a benign tumor of the cortex where there are pale, yellow-gray, discrete and well circumscribed nodules.
Renal papillary adenoma
These are benign tumors made of vessels, smooth muscle and fat.
Angiomyolipoma
What patients are associated with angiomyolipomas?
Tuberous sclerosis
angiomyolipomas are at risk for what?
spontaneous hemorrhage
these are benign tumors of large eosinophilic cells having small, round, benign appearing nuclei that have large nucleoli, and come from the intercalated discs of CD’s.
Oncocytoma
What do the eosinophilic cells have a lot of in ococytomas?
mitochondria
What is the gross morphology of oncocytomas?
large, tan/mahogany brown, relatively homogenous and well encapsulated
This is a malignant epithelial tumors from the kidney tubules and presents with a triad of hematuria, palapble mass, and flank pain.
Renal cell Carcinoma (RCC)
What syndromes are RCC’s associated with?
Paraneoplastic syndromes (EPO, renin, PTHrP, or ACTH)
What may be present in ur ballsack with RCC’s?
L-sided varicocele
What is the morphology of RCC’s?
yellow mass, microscopically the most common variant exhibits clear cytoplasm (clear cell type)
What is the mutated gene in RCC’s?
VHL tumor supressor gene
The loss of VHL causes an ↑ in which 2 regulators?
↑ IGF-1 (promotes growth)
↑ HIF transcription factor (↑ VEGF and PDGF)
Who is at risk for sporadic RCC’s?
adult smoker
Who gets hereditary RCC’s?
younger pts
This is the AD disorder assocaited with the inactivation of the VHL gene, which ↑ the risk for hemangioblastoma of the cerebellum and renal cell carcinoma.
Von Hippel-Lindau disease
This is the form of RCC which is the most common type cells ahve clear or granular cytoplasm and are non-papillary.
Clear cell carcinoma
What gene is mutated to cause the papillary carcinoma?
MET proto-oncogene
This is the form of RCC where there are cells composed of prominent cell membranes + pale eosinophilic cytoplasm—usually has halo around nucleus in the intercalated cells of the CD.
Chromophobe renal carcinoma
This is the rare form of RCC where the CD cells show nests of malignant cells enmeshed within a prominent fibrotic stroma, typically a medually location.
Collecting duct (bellini duct) carcinoma
Where do u find clear cell carcinomas?
PCT
What are the 2 syndromes associated with clear cell carcinomas?
Von Hippel Lindau
Tuberous sclerosis
Tuberous sclerosis is associated with what cardiac tumor?
Rhabdomyoma
This is the most common type of renal cancer in pts who develop dialysis-assocaited cystic disease.
Papillary carcinoma
What do u see in the papillary cores in papillary carcinoma?
Foam cells
These are pale, eosinophilic cells, often with perinuclear halo, arranged in solid sheets with concentration of largest cells around blood vessels
Chromophobe carcinoma
What is the main highway RCC’s take to metastasize?
Renal vein
Should you biopsy a RCC?
NO. NEVER.
Urothelial tumors (transional cell papillomas/carcinomas) of the renal pelvis are often associated with tumors in what locations?
pelvis, ureters, or bladder
