URINARY Section 3: Cystic Diseases

Question 1

Simple - less than 15 HU with no enhancement

Answer 1

Bosniak Class 1

Question 2

Hyperdense (< 3 cm). Thin calcifications, Thin septations

Answer 2

Bosniak Class 2

Question 3

Hyperdense (> 3 cm). Minimally thickened calcifications (5% chance cancer)

Answer 3

Bosniak Class 2F

Question 4

Thick Septations, Mural Nodule (50% chance cancer)

Answer 4

Bosniak Class 3

Question 5

Any enhancement (>15 HU)

Answer 5

Bosniak Class 4

Question 6

Basically, if the mass is greater than 70 HU and homogenous, it’s benign (hemorrhagic or proteinaceous cyst) 99.9% of the time.

Answer 6

Hyperdense Cyst

Question 7

Kidneys get progressively larger and lose function (you get dialysis by the 5* decade). Hyperdense contents & calcified wall are frequently seen due to prior hemorrhage.

Answer 7

Autosomal Dominant Polycystic Kidney Disease (ADPKD)

Question 8

What you nee to know in ADPKDk

Answer 8

(1) it’s Autosomal Dominant “ADult”
(2) They get cysts in the liver 70% of the time,
(3) they get seminal vesicle cysts (some sources say 60%), and
(4) they get Berry Aneurysms.

Question 9

they don’t have an intrinsic risk of cancer, but do get cancer once they are on dialysis.

Answer 9

ADPKD

Question 10

heseguys getHTN and renal failure. The liver involvement is different than the adult form. Instead of cysts they have abnormal bile ducts and fibrosis.

Answer 10

ARPKD

Question 11

What is always present is always present in ARKPD?

Answer 11

Congenital hepatic fibrosis

Question 12

The worse the liver is the better the kidneys do. The better the liver is, the worse the kidneys do.

Answer 12

ARPKD

Question 13

Answer 13

ARPKD

smoothly enlarged and diffusely echogenic, with a loss of corticomedullary differentiation.

Question 14

subacute or chronic renal abscess can look just like a?

Answer 14

cystic renal neoplasm

History of fever, leukocytosis, or previously treated urinary tract infection - all should activate your spider-sense.

If that isn’t available, look for peri-renal stranding and thickening o f the fascia - as shown in this awesome illustration I made (arrow).

Question 15

Lithium Nephropathy can lead to?

Answer 15

Can lead to diabetes insipidus and renal insufficiency.

Question 16

The kidneys are normal to small in volume with multiple (innumerable”) tiny cysts, usually 2-5 mm in diameters. These “microcysts” are distinguishable from larger cysts associated with acquired cystic disease of uremia.

Answer 16

Lithium Nephropathy

Question 17

PKD + lithium (bipolar disorder) =

Answer 17

Lithium Nephropathy

Question 18

Von Hippei Lindau

Answer 18

Autosomal dominant multi-system
disorder.

50-75% have renal cysts.

25-50% develop RCC (clear cell).

Question 19

Renal cysts + Pancreatic cysts =

Answer 19

Von Hippel Lindaw

Question 20

REnal cysts + Hepatic Cysts + big kidneys

Answer 20

ADPKD

Question 21

Renal cysts + small cysts

Answer 21

Acquired Uremic cystic kidney disease

Question 22

The thing to know is: Increased risk of malignancy with dialysis (3-6x).

Answer 22

Acquired Uremic cystic kidney disease

Question 23

Autosomal dominant multi-system disorder. You have hamartomas everywhere (brain, lung, heart, skin, kidneys).

Answer 23

Tuberous Sclerosis

Question 24

multiple bilateral angiomyolipomas + renal cysts + occasionally RCC

Answer 24

Tuberus sclerosis

Question 25

Tuberous Sclerosis can be referred to as

Answer 25

Bourneville Disease (for the purpose o f
fucking with you)

Question 26

Tuberus sclerosis + lung =

Answer 26

LAM - thin walled cysts and chylothorax

Question 27

Tuberus sclerosis + cardiac =

Answer 27

Rhabdomyosarcoma (typically involve cardiac septum)

Question 28

Tuberus sclerosis + Brain =

Answer 28

GC Astrocytoma, Cortical and Subcortical Tubers, Subependymal Nodules

Question 29

Tuberus sclerosis + Renal =

Answer 29

AMLs and RCC in young patients.

Question 30

Answer 30

Calyceal Diverticulum

There will be a round Fluid-Fluid Level near the collecting system

The levels you arc seeing are excreted contrast layered under urine without contrast within the diverticulum.

Question 31

Answer 31

“Milk of Calcium”

Fluid-debris level in the calyceal diverticulum

Question 32

Cysts are supposed to be T2 bright. If you see the “T2 Dark Cyst” then you are deahng with the classic differential of:

Answer 32

1. Lipid poor angiomyolipoma
2. Hemorrhagic ccyst
3. Papillary Subtype RCC

Question 33

Dark T2 cyst + Tuberus slcerosis =

Answer 33

Lipid poor AML

Question 34

Dark T2 cyst + Bright T1 =

Answer 34

Hemorrhagic cyst

Question 35

Dark T2 cyst + enhancement =

Answer 35

Papillary Subtype RCC

RCC bright T2 + enhancment

Question 36

This is the situation where you have multiple tiny cysts forming in utero from some type of insult.

Answer 36

Multicystic Dysplastic Kidney

Question 37

“Nofunctioning renal tissue, ”- shown with MAG 3 exam.

Answer 37

Multicystic Dysplastic Kidney

Question 38

Contralateral renal tract abnormalities occur like 50% of the time. Typically you think of reflux (VUR) and UPJ Obstructions

Answer 38

MCDK

Question 39

MCDK vs Bad Hydro

The cystic spaces are seen to communicate =

No excretory function in renal scintigraphy =

Answer 39

The cystic spaces are seen to communicate = Hydonephrosis

In difficult cases renal scintigraphy can be useful. MCDK will show no excretory function.

Question 40

Para =

Peri =

Answer 40

Para = beside

Peri = around

Question 41

Peripelvic Cyst vs Parapelvic Cyst

Originates from parenchyma, may compress the collecting system. These look a lot like the cortical cysts that you see all the time, but instead of bulging out - they bulge in.

Answer 41

Parapalvice cyst

Question 42

Peripelvic Cyst vs Parapelvic Cyst

Originates from renal sinus, mimics hydro. If you didn’t have a pyelogram (delayed) phase - might be tricky to tell apart.

Answer 42