Cortical Cysts, Para/peripelvic Cysts, Medullary Sponge Kidney (Lecture 19a)

What are cortical cysts? What is the CP? What are the SF?

- Cysts that arise from renal cortex that do NOT communicate w/ collecting system (bilateral)

- CP: asymptomatic (m/c); pain and hematuria if large or infected

SF

- Simple cyst

Complex cyst

- Internal echoes

- Septations: considered benign if septa are less than or equal to 1mm

- Calcifications: milk of calcium - always benign, appear as echogenic foci w/ ringdown

What is the "milk of calcium" sign? What condition is it associated with?

Echogenic foci w/ ringdown associaetd with cortical cysts

What are the m/c renal cysts?

Cortical cysts

What are the d/d for cortical cysts?

- RCC

- MLCN (multilocular cystic nephroma)

- Abscess

What are parapelvic cysts?

Lymphatic cysts that originate from renal cortex but protrude into sinus

What are peripelvic cysts?

Lymphatic cysts that originate from renal sinus (true renal sinus cyst)

What is the CP for peri/parapelvic cysts? What are their SF? What is the d/d?

- CP: asymptomatic (m/c); hematuria, hypertension, and hydronephrosis when infected and large

- SF: well-defined, anechoic, weird shape

- D/D: hydronephrosis

(Hydro = anechoic areas would communicate with calyces and pelvis of kidney;

Parapelvic cyst = don't communicate with collecting system)

What is medullary sponge kidney? What 3 conditions is it associated with? What is pt population and CP? What are the SF? What is the D/D?

- Developmental abnormality characterized by dilated and tortuous collecting tubules (bilateral)

- Associated w/ hyperparathyroidism, ARPKD, Caroli's Disease

- CP: asymptomatic middle aged men; may see hematuria, dysuria, or flank pain w/ hemorrhage or stone formation

- SF: normal size, inc echogenicity of pyramids, shadowing stones

- D/D: nephrocalcinosis

TRUE or FALSE: Nephrocalcinosis and medullary sponge kidney look the exact same on U/S.

TRUE