URINARY Section 3: Cystic Diseases Flashcards
Simple - less than 15 HU with no enhancement
Bosniak Class 1
Hyperdense (< 3 cm). Thin calcifications, Thin septations
Bosniak Class 2
Hyperdense (> 3 cm). Minimally thickened calcifications (5% chance cancer)
Bosniak Class 2F
Thick Septations, Mural Nodule (50% chance cancer)
Bosniak Class 3
Any enhancement (>15 HU)
Bosniak Class 4
Basically, if the mass is greater than 70 HU and homogenous, it’s benign (hemorrhagic or proteinaceous cyst) 99.9% of the time.
Hyperdense Cyst
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.
Autosomal Dominant Polycystic Kidney Disease (ADPKD)
What you nee to know in ADPKDk
(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.
they don’t have an intrinsic risk of cancer, but do get cancer once they are on dialysis.
ADPKD
heseguys getHTN and renal failure. The liver involvement is different than the adult form. Instead of cysts they have abnormal bile ducts and fibrosis.
ARPKD
What is always present is always present in ARKPD?
Congenital hepatic fibrosis
The worse the liver is the better the kidneys do. The better the liver is, the worse the kidneys do.
ARPKD
ARPKD
smoothly enlarged and diffusely echogenic, with a loss of corticomedullary differentiation.
subacute or chronic renal abscess can look just like a?
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).
Lithium Nephropathy can lead to?
Can lead to diabetes insipidus and renal insufficiency.
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.
Lithium Nephropathy
PKD + lithium (bipolar disorder) =
Lithium Nephropathy
Von Hippei Lindau
Autosomal dominant multi-system
disorder.
50-75% have renal cysts.
25-50% develop RCC (clear cell).
Renal cysts + Pancreatic cysts =
Von Hippel Lindaw
REnal cysts + Hepatic Cysts + big kidneys
ADPKD
Renal cysts + small cysts
Acquired Uremic cystic kidney disease
The thing to know is: Increased risk of malignancy with dialysis (3-6x).
Acquired Uremic cystic kidney disease
Autosomal dominant multi-system disorder. You have hamartomas everywhere (brain, lung, heart, skin, kidneys).
Tuberous Sclerosis
multiple bilateral angiomyolipomas + renal cysts + occasionally RCC
Tuberus sclerosis
Tuberous Sclerosis can be referred to as
Bourneville Disease (for the purpose o f
fucking with you)
Tuberus sclerosis + lung =
LAM - thin walled cysts and chylothorax
Tuberus sclerosis + cardiac =
Rhabdomyosarcoma (typically involve cardiac septum)
Tuberus sclerosis + Brain =
GC Astrocytoma, Cortical and Subcortical Tubers, Subependymal Nodules
Tuberus sclerosis + Renal =
AMLs and RCC in young patients.
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.
“Milk of Calcium”
Fluid-debris level in the calyceal diverticulum
Cysts are supposed to be T2 bright. If you see the “T2 Dark Cyst” then you are deahng with the classic differential of:
- Lipid poor angiomyolipoma
- Hemorrhagic ccyst
- Papillary Subtype RCC
Dark T2 cyst + Tuberus slcerosis =
Lipid poor AML
Dark T2 cyst + Bright T1 =
Hemorrhagic cyst
Dark T2 cyst + enhancement =
Papillary Subtype RCC
RCC bright T2 + enhancment
This is the situation where you have multiple tiny cysts forming in utero from some type of insult.
Multicystic Dysplastic Kidney
“Nofunctioning renal tissue, ”- shown with MAG 3 exam.
Multicystic Dysplastic Kidney
Contralateral renal tract abnormalities occur like 50% of the time. Typically you think of reflux (VUR) and UPJ Obstructions
MCDK
MCDK vs Bad Hydro
The cystic spaces are seen to communicate =
No excretory function in renal scintigraphy =
The cystic spaces are seen to communicate = Hydonephrosis
In difficult cases renal scintigraphy can be useful. MCDK will show no excretory function.
Para =
Peri =
Para = beside
Peri = around
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.
Parapalvice cyst
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.
