Renal diseases 2 Flashcards
What 3 things can obstruct the renal pelvis?
1) Calculi (stones)
2) Tumours
3) Ureteropelvic stricture
What 5 things cause intrinsic obstruction of the ureter?
1) Claculi
2) Tumours
3) Sloughed papillae
4) Clots - from trauma
5) Inflammation
What 3 things cause extrinsic obstruction of the ureter?
1) Pregnancy
2) Tumours
3) Retroperitoneal fibrosis
What are the 4 types of causes of obstruction of the urinary tract?
1) Obstruction within the lumen (calculi, strictures, neoplasia)
2) Abnormalities of the wall (congenital, neoplasia)
3) External compression
4) Functional obstruction (neurological conditions, severe reflux)
What are the 3 types of strictures which can cause obstruction of the urinary tract?
1) Post-procedure
2) Post infective
3) Congenital
What is hydronephrosis?
Kidney swells due to obstruction to kidney outflow
What are the 3 key appearances of kidney in hydronephrosis?
1) dilated calyces
2) dilated pelvis
3) Cortical atrophy
What are the 2 possible outcomes of acute complete ureteric obstruction?
1) Could just get mild dilatation and mild cortical atrophy
2) Could lead to reduction in GFR which can cause acute renal failure
Through what 2 pathways does chronic and intermittent renal obstruction lead to fall in renal function?
1) Get continues glomerular filtration - dilation of pelvis and calyces - leading to eventual cortical atrophy and fall in renal filtration
2) Obstruction causes filtrate to pass back into interstitium - leading to compression of medulla - impaired concentrating ability - eventual cortical atrophy with a fall in renal filtration
What are the 2 clinical features of acute bilateral obstruction?
1) Pain
2) Acute renal failure and anuria
What are the 2 clinical features of chronic unilateral obstruction?
1) Asymptomatic initially
2) If unresolved, cortical atrophy and reduced renal function
What is the clinical feature of bilateral partial obstruction?
Initially polyuric with progressive renal scarring and impairment
In which gender and age group are renal calculi most common?
Males aged 20-30
Where do calculi most commonly form?
In the kidney but can form anywhere in the urinary tract
What are the 4 pathogenic mechanisms of renal calculi formation?
1) Due to excess of substances which may precipitate out eg. Ca2+
2) A change in the urine constituents causing precipitation of substances eg. change in pH
3) Poor urine output - supersaturation
4) Decreased citrate levels - citrate combines with calcium and prevents stone formation
What are the 4 classifications of renal stones?
1) Calcium stones - 70% - calcium oxalate +/- calcium phosphate
2) Struvite stones - 15% - magnesium ammonium phosphate
3) Urate stones - 5% - uric acid
4) Cystine stones
What are the 4 most common causes of calcium stone formation?
Hypercalcuria due to:
1) Hypercalcaemia - bone disease, PTH excess, sarcoidosis
2) Excessive absorption of intestinal Ca+
3) Inability to reabsorb tubular Ca+
4) Idiopathic
Name 2 risk factors for calcium stone formation?
1) Gout - forms a core for Ca+ crystal formation
2) Hyperoxaluria - hereditary or excess dietary intake
What are the steps in struvite stone formation?
1) Urease producing bacterial infection (proteus)
2) Urease converts urea to ammonia
3) Causes a rise in urine pH
4) Precipitation of magnesium ammonium phosphate salts
5) Large ‘staghorn’ calculi
What are the 2 pathogenic mechanism of urate stone formation?
1) Hyperuricaemia - gout, patients with high cell turn over eg. lerkaemia
2) Idiopathic
In what situations do cystine stones form?
Occur In presence of an inability of kidneys to reabsorb amino acids
What are the 3 investigations for renal calculi?
1) Non contrast CT scanning is gold standard - sensitivity of >95%
2) US in pregnancy or where CT is not possible - 30-67% sensitivity
3) IV urography 70% sensitive for stones
What is the gold standard imaging technique for renal calculi?
Non contrast CT scanning
Renal cell carcinoma accounts for what percentage of cancers?
3%
The vast majority of renal carcinomas are what kind?
Clear cell
What are the 2 rarer variants of renal carcinomas?
1) Papillary
2) Chromophobe
What is the peak age for incidence of renal carcinoma, which gender is it most common in?
Males
Aged 65-80 years old
What is the main risk factor for renal carcinomas?
Tobacco
What are the 6 risk factors for renal carcinoma?
1) Tobacco
2) Obesity
3) Hypertension
4) Oestrogens
5) Aquired cystic kidney disease (due top chronic renal failure)
6) Asbestos exposure
What is Von Hippel-Lindau Syndrome?
The most common of several cancer syndromes observed in renal cell carcinoma. Mutations in VHL gene - tumours develop in kidneys blood vessels and pancreas
Other than Von Hippel-Lindau syndrome what other condition have VHL mutations been commonly seen?
Clear cell renal cell carcinoma
What is the VHL gene responsible for, why does this lead to development of tumours in kidneys, blood vessels and pancreas?
VHL gene required for the breakdown of Hypoxia Inducible Factor- 1 (HIF-1) oncogene
Loss of gene function causes cell growth and increased cell survival
What are the 3 local symptoms of renal cell carcinoma?
1) Haematuria
2) Palpable abdominal mass
3) Costovertebral pain
What would be the symptoms on late presentation of renal cell carcinoma?
Systemic symptoms or Metastases (25%)
What are paraneoplastic syndromes?
Clinical syndromes caused by tumours
Not related to the tissue that the tumour arose from
Not related to invasion by the tumour itself or metastases
Give 6 common paraneoplastic syndromes associated with RCC?
1) Cushing’s syndrome
2) Hypercalcaemia
3) Polycythaemia
4) ACTH
5) Parathyroid hormone related peptide
6) Eryhthropoietin
What is the macroscopic morphology of clear cell renal cell carcinoma? 3
1) Well defined yellow tumours
2) Often with haemorrhagic areas
3) May extend in perinephric fat or renal vein
What is the macroscopic morphology of papillary renal cell carcinoma? 2
1) More cystic
2) More likely to be multiple
What is the microscopic appearance of clear cell renal cell carcinoma? 3
1) Clear cell has clear cells
2) Delicate vasculature
3) Usually small bland nuclei
What is the microscopic appearance of papillary renal cell carcinoma? 2
1) Cuboidal, foamy cells
2) Surrounding fibrovascular cores often containing foamy macrophages or calcium
What is the overall 5 year survival rate for renal cell carcinoma?
~45%
What is the 5 year survival rate for organ confined renal cell carcinoma?
> 70%
What is the 5 year survival rate for renal tumours extending into perinephric fat or renal vein?
~50%
Why in renal cell carcinoma with distant metastases is the prognosis so poor?
Renal cell carcinoma tends to be chemo-resistant
Urothelial cell carcinoma account for what percentage of bladder tumours?
95%
What is the most common site of urothelial cell carcinoma?
Bladder but may arise anywhere from renal pelvis to urethra
What are the 6 risk factors for urothelial cell carcinoma?
1) Age
2) Gender (male >female)
3) Smoking
4) Arylamines (dyes)
5) Cyclophosphamide (Drug)
6) Radiotherapy
What is the most common symptom on presentation with urothelial cell carcinoma?
Haematuria
What are the 4 most common symptoms on presentation with urothelial cell carcinoma?
1) Haematuria
2) Urinary frequency
3) Pain on urination
4) Urinary tract obstruction
What are the 4 main histological patterns in urothelial cell carcinoma?
1) Papilloma - papillary carcinoma
2) Invasive papillary carcinoma (invaded below lamina propria/muscle layer)
3) Flat non invasive carcinoma (CIS)
4) Flat invasive carcinoma
What are the 7 catergories in T staging of bladder carcinoma?
Ta = noninvasive, papillary Tis = carcinoma in situ (non invasive flat) T1 = lamina propria invasion T2 = Muscularis propria invasion T3a = microscopic extra-vesicle invasion T3b = grossly apparent extra-vesicle invasion T4 = invades adjacent structures
What is the 5 year survival for low grade TCC (bladder carcinoma)?
98%
What is the 5 year survival for muscle invasive bladder carcinoma?
60%
What is urolithiasis?
Formation of renal calculi
