Benign stuff Flashcards
What can be used to ablate a benign, symptomatic renal mass with over 90% success rate?
95% EtOH
Peripelvic or renal sinus cysts originate from lymphatics or parenchyma?
Lymphatics
A hyperdense benign renal cyst defers how on CT non-contrast vs. CT with contrast
they look the same; similar HUs on both (i.e. non-enhancing with contrast)
Two mutations for ADPKD?
Chromosome 16p (PKD1; polycystin-1)
Chromosome 4 (PKD2; polycystin-2)
Why may urinalysis be negative even though cysts are infected in PKD?
the cortical renal cysts are not contiguous with the collecting tubules
Lipophilic antibiotics penetrate infected cysts better than hydrophilic antibiotics; therefore, which abx are recommended?
Ciprofloxacin
Bactrim (trimethoprim/sulfmethoxazole)
Clindamycin
Chloramphenicol
If infection of cysts cannot be cleared with antibiotics, then what do you do?
Percutaneous drainage
ADPKD are also associated with abnormalities in what other two organs?
Hepatic cysts in the liver
Berry aneurysms in the brain
- screen with MRA after age 30
Is ADPKD associated with increased RCC?
NO
ARPKD mutation?
Chromosome 6 (PKHD1, fibrocystin)
Is ARPKD associated with cysts in other organs?
No
What happens in the liver in ARPKD?
Congenital hepatic fibrosis, biliary atresia
Rate of renal failure in ADPKD? ARPKD?
ADPKD = ~50% by adulthood (30 years)
ARPKD = 100%, and at young age
What is nephronophthisis?
MEDULLARY cystic disease formed at the corticomedullary junction
- due to AR mutation in ciliary proteins
Do ppl with nephronophthisis develop ESRD?
yes, inevitable
The three forms of nephronophthisis are infantile, juvenile, and adolescent. Which is most common, and what is it associated with?
Juvenile is MC
Associated with retinitis pigmentosa.
Treatment of nephronophthisis?
Supportive care. Transplant when ESRD
What is the benign disorder with cysts that develop in the collecting ducts?
Medullary sponge kidney
What mutation is associated in medullary sponge kidney?
What syndrome has high prevalence of medullary sponge kidney?
RET oncogene, although the majority are sporadic
Beckwith-Wiedemann Syndrome/hemihypertrophy
Imaging buzzword associated with medullary sponge kidney?
“paint brush-like” appearance of calyces on KUB
Nephrocalcinosis has many etiologies, including medullary sponge kidney. What are the other etiologies?
- Hyper PTH
- Distal RTA (type 1)
- Renal TB
- Papillary necrosis
- Hyperoxaluria
- Medullary sponge kidney
Multicystic dysplastic kidney is a functional/non-functional kidney?
non-functional; renal maldevelopment causing many cortical cysts and absent calyceal system
MCKD is associated with increased what in the contralateral, healthy kidney?
- Vesicoureteral reflux, **therefore recommend screening with VCUG
- UPJO
MCKD is associated with normal/abnormal renal function in an infant?
Normal. The contralateral kidney hypertrophys
What is the treatment for MCKD?
None usually; the kidney will likely involute.
*Nephrectomy if uncontrolled HTN, pain, or SOB due to diaphragm irritation
Oncocytomas are derived from which part of the nephron?
Which subtype of RCC is also derived from the same part, and therefore has similar histologic findings?
Distal tubules
*Chromophobe RCC also originates from distal tubule
Can you radiographically distinguish oncocytoma from RCC?
No. Therefore, treat it as a RCC
What syndrome is associated with increased development of oncocytomas and chromophobe RCCs?
Hint: also see cutaneous fibrofolliculomas and pulmonary cysts
Birt-Hogg-Dube syndrome
Definitive treatment of an oncocytoma?
Since you don’t know it’s oncocytoma until its taken out….
Partial/radical nephrectomy or thermal ablation
What is the benign tumor derived from perivascular epitheliod cells and has adipose, smooth muscle, and blood vessels?
Angiomyolipoma
AMLs have strong male/female predilection?
Female (80%)
What is the variant of AML that has a paucity of fat and about 1/3 malignant potential?
Epitheliod
What is the imaging finding for AML that is pathognomonic?
Negative HU’s on CT
AML has a histologic stain of _____, which melanoma is also positive for.
HMB-45 positive
What is Wunderlich syndrome?
massive retroperitoneal hemorrhage of an AML
- occurs in 10% of AMLs and more likely in pregnancy
Lenk’s Triad of Wunderlich syndrome
acute flank pain
palpable tender abdominal mass
symptoms of internal bleeding (tachycardia, hypoT, shock)
The eponyms for flank ecchymosis and umbilical ecchymosis?
flank ecchymosis = Grey Turner sign
umbilical ecchymosis = Cullen’s sign
What are the 3 MC etiologies of retroperitoneal hemorrhage?
- AAA
- RCC
- AML
Treatment options for AML?
- None if small, asymptomatic
* *2. If > 4cm, then partial/radical nephrectomy or embolization (due to risk of rupture) - If epitheliod variant, treat as RCC (surveillance vs. remove)
What syndrome has a strong association of AML’s?
Hint: also see sebaceous adenoma, seizures, mental retardation?
Tuberous sclerosis
“zits, fits, deficits”, and AMLs
Tuberous sclerosis is Auto dominant or Auto recessive?
AD
Mutations for TS?
9q34 (TSC1)
16p14 (TSC2)
AML’s in a pt with TS behave differently how?
They grow faster
- 5% annual normally; in TS, 20% annual growth rate
What chemotherapy drug is indicated in patients with TS and have AMLs?
Everolimus (mTOR inhibitor)
- also treats the subependymal giant cell astrocytoma (SEGA) seen in TS and also help with the increased risk of RCC
This benign tumor is a Bosniak 3-4 cystic renal mass and is seen in perimenopausal women as it is related to estrogen therapy.
What does it stain positive for?
Treatment
Mixed Epithelial Stromal Tumor of the Kidney (MESTK)
Stains positive for ESTrogen/progesterone receptors
Treatment is partial/radical nephrectomy (Bosniak 3-4)
What differentiates between a benign papillary adenoma and a papillary RCC?
Size. Adenoma MUST be < 5mm; if > 5mm then its papillary RCC
Treatment of papillary adenoma?
Remove or ablate
Mutation seen in papillary adenoma
same as in papillary RCC, trisomy of chromo 7 and 17
