Cystitis and Tumors of Kidney Flashcards
(41 cards)
Adult polycistic kidney disease
- Autosomal dominant
large, multicycstic kidneys, liver cysts, berry aneurysms
hematuria, flank pain, UTI, renal stones, HTN
chronic renal failure beginning at age 40-60 years
childhood polycystic kidney
Autosomal recessive
enlarged, cystic kidneys at birth
hepatic fibrosis
death in infancy or childhood
medullary sponge kidney
no inheritance
- medullary cysts on excretory urography
- see hematuria, UTI, recurrent renal stones
- cortical scarring is absent
- Benign
Familial juvenile nephronophthisis
- autosomal recessive
- corticomedullary cysts and shrunken kidneys
- salt wasting, polyuria, growth retardation
- progressive renal failure from childhood
adult-onset nephronophthisis
- Autosomal dominant
- Corticomedullary cysts, shrunken kidneys
- Salt wasting, polyuria
- Chronic renal failure adult onset
simple cysts
no inheritance pattern
- single or several cysts in normal sized kidneys, translucent, lined by grap smooth membrane filled with clear fluid
- see microscopic hematuria (on occasion see hemorrhage and sudden distention/pain)
- benign (do not bulge from cortex, as might be seen in carcinoma)
- in contrast to renal tumors, renal cysts have smooth contours and are almost always avascular, and give fluid rather than solid signals on ultrasonography
acquired renal cystic disease
- no inheritance (dialysis associated)
- cystic degeneration in end-stage kidney
- see hemorrhage, erythrocytosis, neoplasia, hematuria
- see calcium oxalate crystals
- 18 fold increased risk of renal cell carcinoma
- reqs. dependence upon dialysis
multicystic renal dysplasia
- no inheritance
- irregular kidneys w/ cysts of various sizes
- assoc. w/ other renal abnormalities
- most cases assoc. w/ ureteropelvic obstruction, ureteral agenesis/atresia
- renal failure occurs if bilateral, if unilateral it is surgically correctable
Genetics of ADPKD?
- PKD1 gene mutation: (85%) encodes membrane protein polycystin-1 which is expressed in tubular epithelial cells, esp, the distal nephron
- PKD2 gene mutation: (15%) encodes polycystin-2, an integral membrane protein expressed in all segements of renal tubules and functions as a Ca2+ permeable cation channel
- defects in mechanosensing and Ca2+ flux underlie cyst formation – PKD1/PDK2 form a complex that regulates intracellular Ca2+ in response to fluid flow
- mutation leads to loss of plycystin complex and disruption of downstream signaling events
- increase in Ca2+ stimulates proliferation and secretion from epithelial cells lining the cysts
clinical features of ADPKD?
• many remain asymptomatic until later years
• hemorrhage and pain
• ecretion of blood clots → renal colic
• enlarged kidneys, hematuria, proteinuria, polyuria, HTN
• patients w/ PKD2 have older age of onset, less aggressive
• progression worse in blacks, males and people w/ HTN
• individuals also tend to have extrarenal congenital anomalies
• 40% have cysts also occur in other places (liver, spleen, pancreas, lungs, intracranial berry aneurysms)
o 4-10% die of subarachnoid hemorrhage (berry aneurysms in circle of willis)
o mitral valve prolapse
o diverticualar disease of colon
• PKD1 is most likely to develop ESRF than PKD2
• insidious onset presenting in 4th-6th decade w/ renal insufficiency (hypertension and azotemia)
• may exhibit abdominal pain due to cyst enlargement and hemorrhage → hematuria
pathogenesis/morphology of childhood polycstic kidney disease
• serious complications at birth – the young usually succumb rapidly to renal failure
Pathogenesis:
• mutations in PKHD1 gene on chromosome 6: encodes fibrocystin – which may be a cell surface receptor w/ a role in CD and biliary differentiation
Morphology:
• kidneys are enlarged and have smooth external appearance
• small cysts in cortex/medulla give sponge appearance
• dilated elongated channels are present radially, at right angles to the cortical surface
clinical features of autosomal recessive PKD?
- “congenital hepatic fibrosis” patients who survive develop hepatic injury characterized by bland periportal fibrosis
- hepatic disease is dominant concern in older children
- development of portal HTN and splenomegaly
Perinatal: most common – 90% of CD are cystic; minimal hepatic fibrosis, only survive a few hours
Neonatal: 60% of CD are cystic; mild hepatic fibrosis: generally survive a few months, die from renal failure
Infantile: 20% CD are cystic; hepatic fibrosis/failure, portal HTN – 90% survive but die in early childhood
Juvenile: <10% CD are cystic, hepatic fibrosis is progressive and portal HTN results in death in adolescence
Nephronopthisis
- variable number of cysts in the medulla, usually concentrated at the corticomedullary junction
- cortical tubulointerstitial damage is the cause of eventual renal insuff.
present w/ polyuria and polydipsia, sometimes also sodium wasting and tubular acidosis
as a group, now considered to be the most common genetic cause of ESKD in adolescence/young adults
• should be strongly considered in children w/ otherwise unexplained chronic renal failure
Pathogenesis:
• mutations in MCKD1 and MCKD2 have been identified in causing medullary cystic disease
• mutations in NPH1/2/3 underlie juvenile form of nephronphthisis
Morphology:
kidneys are small, contracted granular surfaces, cysts in the medulla at corticomedullary junction
non-familial congenital unilateral multicystic renal dysplasia
• most common congenital renal cystic disease: 1 in 4000 live births
• Caused by failure of the ureteric bud to reach renal blastema during embryologic development and stimulate formation of the renal cortex and associated development of the nephron. 90% cases have an absent ureter (agenesis) or ureteropelvic obstruction
Pathologic findings:
• Extensive multiple variably-sized cysts with intervening rather poorly-differentiated mesenchyme (often cartilage formation)
• No development of glomeruli
• Generally no increased incidence of additional or concomitant congenital abnormalities
hydronephrosis
= dilation of renal pelvis and calyces assoc. w/ progressive atrophy of the kidney due to obstruction to the outflow of urine
• even w/ complete obstruction, glomerular filtration remains b/c filtrate diffuses back into renal interstitium and perirenal space
• high pressure in pelvis transmitted back through CD and into the cortex → renal atrophy, compressing renal vasculature in medulla → dinishing medullary blood flow
• obstruction also triggers interstitial inflamm. rxn → interstitial fibrosis
clinical features of hydronephrosis?
- calculi lodged in ureters → renal colic
- prostatic enlargements → bladder sx
- unilateral hydronephrosis → unaffected kidney maintaining adequate renal fn.
- bilateral partial obstruction → inability to concentrate urine, polyuria and nocturia, distal tubular acidosis, salt wasting, nephritis, scarring and HTN
- complete bilateral obstruction → oliguria/anuria and death if not corrected
urolithiasis
(Renal Calculi, Stones) or “nephrolithiasis”
• affects 5-10% of Americans (most just unilaterally)
• men affected more, peak onset age 20-30 y/o
• familial/hereditary predisposition
• when kidney stones enter the ureter may cause intense pain renal colic, ulceration and bleeding of ureter and obstruction of urinary flow
• major determinant to stone formation is urinary concentration of constituents and supersaturation
• urinary pH and decreased urine volume also play role in formation
• become lodged in renal calyces and pelves
calcium oxalate sontes
70% (radiopaque - white)
• most common finding is hypercalciuria (some have hypercalcemia as well)
• hyperparathyroidism is uncommon cause of stone formation
• diffuse bone disease and sarcoidosis
• hyperabsorption of Ca2+ from intestine
struvite stones
(Magnesium ammonium phosphate) – 20%
• formed after infections by urea-splitting bacteria
• alkaline urine causes their precipitation
uric acid stones
– 5% (radioluscent - black)
• most have neither hyperuricemia nor increased urinary excretion of uric acid
• pH of urine below 5.5 may be disposing factor
renal papillary adenoma
“renal cortical adenoma”
- most common of benign neoplasms
• small, discrete adenomas arising from renal tubular epithelium
• small cortical tumors w/ pale yellow-gray discrete well circumscribed nodules
• histologically don’t differ from low grade papillary renal cell carcinoma but are usually less than 3 cm (separating them from those that metastasize)
note: Adenoma is used for benign epithelial neoplasm derived from glands
• neoplasms over 1 cm now often considered low grade renal cell carcinoma
angiomyolipoma
benign neoplasm of vessels, smooth mm. and fat
• angiomyolipomas are present in 25-50% of pt. w/ tuberous sclerosis – caused by loss-of-function mutation in the TSC1 or TSC2 tumor suppressor genes
Tuberous sclerosis characterized by epilepsy, mental retardation, skin abnormalities and benign tumors
may cause spontaneous hemorrhage
oncocytoma
epithelial benign neoplasm made of large eosinophilic cells (5-15% of primary renal epithelial neoplasms)
• tumors are tan to mahogany brown, homogenous, and usually well encapsulated with a central scar
• arise from type A intercalated cells of renal cortical collecting ducts (imp. in acid-base hemostasis)
• present in adulthood, and can be large
• can be mistaken for renal cell carcinoma, though these rarely metastasize
Renal cell carcinoma
(Adenocarcinoma of the kidney)
• most common in ages 50-70 y/o w/ males more heavily affected
• 85% of renal cancers in adults
• arises from renal tubular epithelium
• renal cell carcinoma tends to invade the renal vein, may grow as solid column of cells up the IVC → right atrium
• only adenocarcinoma that elaborates fats (they are lipid positive!)
