Renal cyst disorders Flashcards
Renal cyst disorders - types
- Autosomal dominant polycystic kidney disease (ADPKD)
- Autosomal recessive polycystic kidney disease (ARPKD)
- Medullary cystic disease
- Simple renal cysts
- complex renal cysts
Autosomal dominant polycystic kidney disease - gross appearance
Numerous cysts in cortex and medulla –> bilateral enlarged kidneys ultimately destroy kidney parenchyma
Autosomal dominant polycystic kidney disease - present with (clinical presentation)
- flank pain
- hematuria
- hypertension
- urinary infection
- Progressive renal failure (50%)
Autosomal dominant polycystic kidney disease - Mechanism
PKD1 mutation (85% - ch 16) PKD2 mutation (15% - ch 4)
Autosomal dominant polycystic kidney disease - death from
complications of chronic kidney disease or hypertesnion
Autosomal dominant polycystic kidney disease - mechanism of hypertension
high renin production
Autosomal dominant polycystic kidney disease is associated with
- berry aneurysm
- mitral valver prolapse
- benign hepatic cysts
Autosomal dominant polycystic kidney disease - treatment
ACE inhibitors or ARBs
Autosomal recessive polycystic kidney disease - gross appearance and age
Cystic dilation of collecting ducts
often present in infancy
Autosomal recessive polycystic kidney disease is associated with
- congenital hepatic fibrosis
2. Significant oliguric renal failure in utero –> Potter sequence
Autosomal recessive polycystic kidney disease - concern beyond neonatal period include
- hypertension
- progressive renal insufficiency
- portal hypertension (from congenital hepatic fibrosis)
Medullary cystic disease - histology and mechanism
Inherited disease causing tubulointerstitial fibrosis and progressive renal insufficiency with inability to concentrate urine
Medullary cystic disease - gross
Medullary cysts usually not visualised
shrunken kidneys on ultrasound
Medullary cystic disease - US
shrunken kidneys
Medullary cystic disease - prognosis / complications
poor –> progressive renal insufficiency with inability to concentrate urine
The majority of all renal masses
simple renal cysts
Simple cysts are filled with? presentation?
filled with ultrafiltrate (anechoic on US)
found incidentally and typically asymptomatic
Complex cysts - management
Complex cysts, inducing these that are septated, enhanced, or have solid components on imaging requires follow-up or removal due to risk of renal cell carcinoma
Renal cyst disorder with increased renin secretion
Autosomal dominant polycystic kidney disease
Renal tubular acidosis - definition
disorder of the renal tubules that leads to normal annion gap (hyperchloremic) metabolic acidosis
Renal tubular acidosis - types
- Distal tubular acidosis (type 1)
- Proximal renal tubular acidosis (type 2)
- Combined proximal and distal renal tubular acidosis (type 3)
- Hyperkalemic renal tubular acidosis (type 4)
Distal tubular acidosis (type 1) - mechanism
defect in ability of α intercaleted cells to secrete H+ –> no new HCO3 is generated (CL/HCO3- exchanger in the basolateral membrane) –> metabolic acidosis and urine ph more than 5.5
Distal tubular acidosis (type 1) is associated with (an mechanism)
- hypokalemia (α-cell cannot secrete H+, and cannot reabsorb K+, maybe because H+/K+ pump)
- high risk for calcium phosphate kidney stones (due to increased urine pH and increased bone turnover
causes of Distal tubular acidosis (type 1)
- amphotericin B toxicity
- analgesic nephropathy
- congenital anomalies (obstruction of urinary tract)
Proximal renal tubular acidosis (type 2) - mechanism
defect in PCT HCO3 reabsorption –> increased excretion HCO3- in urine and subsequent metaboli acidosis. Urine is acidified by α-intercalated cells in collecting tubule (urine ph less than 5.5)
causes of Proximal renal tubular acidosis (type 2)
- Fanconi syndrome
2. carbonic anhydrase inhibitors
Proximal renal tubular acidosis (type 2) is associated with
- hypokalemia
2. high risk for hypophosphatemic rickets (low phosphate - maybe from Fanconi)
Hyperkalemic renal tubular acidosis - mechanism
Hypoadlosterinism –> hyperkalemia –> low NH3 synthesis in PCT –> low NH4+ excretion –> urine ph less than 55
causes of Hyperkalemic renal tubular acidosis (generally)
- low aldosterone production
2. aldosterone resistance
example of low aldosterone production causes
- diabetic hyporeninism
- ACE inhibitors
- angiotensin receptor blockers
- NSAID
- heparin
- cyclosprorine
- adrenal insufficiency
example of aldosterone resistance causes
- K+ sparing dieuretics
- nephropahty due to obstruction
- TMP/SXM
Renal tubular acidosis - types/urine ph/sodium concentration
- Distal tubular acidosis (type 1) - urine ph more than 5.5 - hypokalemia
- Proximal renal tubular acidosis (type 2) - urine ph less than 5.5 - hypokalemia
- Hyperkalemic renal tubular acidosis (type 4) - urine ph less than 5.5 - hyperkalemia
Renal tubular acidosis - causes of every type
Distal (type 1) –> a. amphotericin B toxicity b. analgesic nephropathy c. congenital anomalies (obstruction) of urinary tract
Proximal (type 2) –> a. Fanconi syndrome b. carbonic anhydrase inhibitors
Hyperkalemic (type 4) –> decreased aldosterone production (diabetic hyporeninism, ACE inhibitors, ARB, NSAIDs, heparin, cyclosporine, adrenal insufficiency) or aldosterone resistance ( K+-sparing diuretics, nephropathy due to pbstruction, TMP/SXM)
