Summary of Renal Cystic Diseases

Question 1

Multicystic kidney disease

Answer 1

Congenital abnormality of kidney and urinary tract where irregular cysts replace normal renal parenchyma; spontaneous involution of cysts may lead to unilateral atrophic nonfunctioning kidney; association with vesicoureteral reflux

Question 2

Nephronophthisis: Tubulointerstitial kidney diseases (small kidneys)

Answer 2

Autosomal dominant:

Mutations of uromodulin (Tamm Horsfall protein), mucin 1, prorenin, or HNF-1b; early hyperuricemia and gout are associated with UROMOD and REN mutations.

Question 3

Nephronophthisis: Tubulointerstitial kidney diseases (small kidneys)

Answer 3

Autosomal recessive:

NPHP1-3, multiple other syndromes associated with small kidneys and often abnormal eye findings (e.g., retinitis pigmentosa)

Question 4

Autosomal-dominant or spontaneous germ line and somatic mutation: TSC

Answer 4

Tuberous sclerosis: hamartomas, AML

TSC/PKD1 continuous gene deletion syndrome: enlarged polycystic kidney disease similar to ADPKD

Question 5

Autosomal-dominant or spontaneous germ line and somatic mutation: TSC

Answer 5

Von Hippel–Lindau disease: associated with multiorgan malignancies including RCC, pheochromocytoma, pancreatic islet cell tumor/cysts, hemangioblastomas

Question 6

Polycystic kidney disease

Answer 6

Autosomal recessive

Kidneys are enlarged in utero and infancy but may reduce in size with age due to fibrosis; association with hepatobiliary fibrosis, ascending cholangitis, ultrasound notable for radially arrayed dilated collecting ducts spanning from cortex to medulla.

Question 7

Polycystic kidney disease

Answer 7

Autosomal dominant

Enlarged kidneys; PKD1 reaches ESRD by fourth decade versus sixth decade by PKD2; association with polycystic liver disease

Question 8

Medullary sponge kidney disease

Answer 8

Bilateral multiple spherical cysts (1 to 8 mm) or diffuse linear striations arise from distal convoluted tubules or collecting ducts in that papillae +/− calcium apatite concretions. Classic CT finding of “paintbrush” or “bouquet of flowers” sign

Question 9

Acquired cysts

Answer 9

Simple cysts: increased with age; may be associated with reduced renal mass, increased body mass index, reduced kidney function

Acquired cystic kidney disease (associated with CKD)

Question 10

Others:

Answer 10

Bengin (multilocular) cystic nephroma (may appear malignant, i.e., Bosniak class III), glomerulocystic kidney disease (familial, sporadic, or infantile manifestation of ADPKD)