Page 24 Flashcards
APW and RPW values of Adrenal adenoma
15 min - APW >60%
- RPW >40%
10 min - APW >52%
- RPW >40%
Pollack + Brant: What adrenal tumors are called “10% tumors”?
PHEOCHROMOCYTOMA
10% extra-adrenal locations,
10% are bilateral,
10% are malignant,
10% familial,
10% incidental
Extra-adrenal sites for pheochromocytoma
organ of Zuckerkandl near aortic bifurcation and near the origin of the IMA, bladder, and para-aortic sympathetic chain
With what conditions is pheochromocytoma associated?
MEN II, vHL (type II), NF1, Carney
(Dunnick) How are pheochromocytomas that arise from parasympathetic tissue of the CNs or vagus called?
glomus tumors, chemodectomas, or carotid body tumors
(Dunnick) How are extra-adrenal pheochromocytomas or those that arise from sympathetic paraganglia called?
paragangliomas
(Dunnick) In what part of the adrenal gland is hematoma usually found?
medulla
(Dunnick) On which side is congenital UPJ obstruction more common?
left
Side more commonly affected in unilateral adrenal hemorrhage
right (this may be from acute rise in venous pressure, which is directly transmitted to the R adrenal gland because the R adrenal vein enters the IVC directly)
(Dunnick) Which direction of crossed ectopy is more common?
left to right
(Dunnick) Side of predilection of multicystic dysplastic kidney
left
Which diseases may cause diffuse adrenal calcification assoc with Addison disease?
TB and histoplasmosis
Adrenal tumors that calcify in children
neuroblastoma and ganglioneuroma
(Dunnick) Ureteral dilatation in pregnancy is more pronounced in which side?
right (because of slight differences in the angles at which the arteries and ureters cross)
(Dunnick) On which side is renal vein thrombosis more common?
left (left renal vein is longer than the right)
(Dunnick) More common side for ovarian vein thrombosis
right
(Dunnick) Ureteral involvement by Crohn disease usually occurs in which side?
right
Size of nodule that is suspicious for malignancy
> 4 cm (Dunnick >3 cm)
Adrenal tumors that calcify in adults
adrenal ca, pheochromocytoma, and ganglioneuroma
Adrenocortical ca syndromes
Beckwith-Wiedemann syndrome, Carney complex, FAP, Li-Fraumeni ca syndrome, MEN-1
Usually the most difficult adrenal tumors to detect because they tend to be the smallest
adenomas in Conn syndrome
Tumors that may rarely secrete ACTH
oat cell ca, bronchial adenoma, tumors of the ovary, pancreas, thymus, and thyroid
Small medullary lesions may be missed in this phase?
Corticomedullary - cortex enhances before medulla
MRI appearance of adenomas
relatively low signal on both T1 and T2 (to differentiate from mets, mets have high T2 signal)
What is the method of choice in the evaluation of hematuria?
CT urogram
What are the phases of CT urogram?
Corticomedullary (30-40s), nephrographic (120s), pyelogram / excretory (3-5 mins)
What is the innermost zone of the medulla, closest to the draining calyx?
papilla
What is this anatomic variant caused by the incomplete fusion of the upper and
lower poles of the kidney? What is its classic US appearance?
Junctional parenchymal defect - wedge-shaped echogenic defect between upper and middle thirds of kidney
What other anomalies should you look for in patients with unilateral renal agenesis?
Genital tract anomalies in females, ipsilateral adrenal agenesis (10%) or hypertrophic adrenal
What is the MC renal fusion anomaly?
Horseshoe kidney
(Dunnick) Which condition is commonly associated with horseshoe kidney?
UPJ obstruction
(Dunnick) What rare abnormality is marked by extensive fusion between the 2 renal masses?
lump or pancake kidney
What are the subtypes of RCC?
Conventional clear cell, multilocular clear cell, papillary, chromophobe, renal medullary
What is the MC solid renal mass in adult?
RCC
What is the MC type of RCC?
Conventional clear cell - 80%
(Dunnick) WHO classification of RCC and their sites of origin
- conventional / clear cell - PCT
- papillary - PCT
- chromophobe - collecting duct
- collecting duct ca - medullary collecting duct
- renal oncocytoma - collecting duct
- unclassified
Fat density in a solid tumor without calcification is diagnostic of what lesion?
AML
(Dunnick) What type of RCC is oncocytoma difficult to distinguish from?
Chromophobe
What type of RCC has the best prognosis?
Chromophobe
How can you differentiate clear cell from papillary or chromophobe RCC?
- clear cell - avid heterogeneous enhancement
- papillary, chromophobe - less enhancement, more peripheral/homogeneous
What are features to look for in evaluating for RCC?
Extension beyond Gerota’s fascia, involvement of renal vein or IVC, distant mets
What are predisposing conditions for RCC?
VHL, hereditary papillary RCC, acquired cystic disease from long-term HD, smoking, renal transplant, HIV
-peripheral pattern of enhancement?
chromophobe, collecting duct as well as papillary
What is the method of choice for tumor evaluation and staging?
CT with contrast
-conventional
hypervascular and heterogeneous
(Dunnick) CT enhancement pattern of RCCs:
-papillary
low level of enhancement and homogeneous (may be confused with complicated renal cyst)
How can you differentiate bland thrombus from tumor thrombus?
Bland thrombus - filling defect expanding vein/IVC with contrast; tumor thrombus - enhancing mass within vein/IVC
How can you differentiate AML from RCC?
AML-fat without calci, necrosis rare; RCC-fat with calci, necrosis more common, usually more heterogeneous
How do RCCs appear on US?
Heterogeneously hypoechoic or mildly hyperechoic, hemorrhage/necrosis appears cystic
(Dunnick) Distinguish the MRI appearance of conventional from papillary RCC
on T2, hypo si papillary, hyper si conventional
How do most RCCs appear on MRI?
Heterogeneous on T2, high T1 may represent tumoral hemorrhage; clear cell - iso/slightly hypo T1, hypervascular with avid enhancement; papillary - hypo T1/T2, low-level homogeneous enhancement
Distribution and location of AML in patients with tuberous sclerosis?
multicentric and bilateral
To include RCC as a consideration in a lesion with macroscopic fat, what should be a concomitant finding?
calcification
What is the most reliable finding of AML on MRI?
Decrease in signal in fat-sat images
(Dunnick) Rare occurences but renal masses which may demonstrate macroscopic fat
Wilms tumor, oncocytoma, mets, RCC
What well-encapsulated benign renal neoplasm is indistinguishable from RCC by all
imaging methods and must be surgically removed to confirm diagnosis?
Oncocytoma
What is the appearance of the central scar of an oncocytoma?
low on T1 and T2
What are the patterns of renal involvement of lymphoma?
Diffuse disease (enlarged kidney), multiple bilateral solid renal masses, solitary bulky tumor, perirenal tumor, tumor invasion from retroperitoneum into renal sinus
What feature of a large oncocytoma is suggestive of its diagnosis?
Central stellate scar
What are common primary tumors to metastasize to the kidneys?
Lung, breast, colon, melanoma
How can you differentiate oncocytoma and RCC on T1?
oncocytoma - hypointense, RCC - intermediate signal to high signal
Wilms tumor associations
sporadic aniridia, hemihypertrophy, Drash syndrome, Beckwith-Wiedemann syndrome
What are the endocrine manifestations of renal adenoca?
HTN (renin), erythrocytosis (erythropoietin), hypercalcemia (PTH), galactorrhea (prolactin), gynecomastia (gonadotropin), Cushing syndrome (ACTH) - kaya tinawag na internist’s tumor
How will bulky adenopathy displace the proximal ureters?
laterally (because proximal ureters lie lateral to the para-aortic nodes)
What are the US criteria for simple cyst? 4
Round/oval anechoic mass, increased through transmission, sharply defined far wall, thin or imperceptible cyst wall
How will bulky adenopathy displace the distal ureters?
medially (external iliac nodes are lateral to the distal ureters)
..CT criteria? 4
Sharp margination with renal parenchyma, no perceptible wall, homogeneous attenuation near water (-10 to +10HU), no enhancement
What is the MC renal mass?
Simple cyst
..MR criteria? 4
Homogeneous, sharply defined round/oval mass, homo low T1, homo low T2 (similar to urine), no enhancement
What characteristics disqualify a cyst form being simple?
internal debris, echogenic clot, fluid-debris levels, thick septations/wall, internal vascularity, thick/coarse calci
What Bosniak classification requires surgical management?
Bosniak III-IV
What are the differential diagnoses for a complicated cystic mass?
hemorrhage/infection, cystic tumor, abscess, obstructed upper pole duplicatio, calyceal diverticulum, lymphoma, aneurysm, pseudoaneurysm
What Bosniak category includes cysts with thick or nodular calcification in the wall or septa?
IIF
(Dunnick) What Bosniak category are exophytic hyperdense cysts? (Si brant, nakaspecifiy na <3 cm iyong size)
II
What Bosniak classification is likely benign but requires follow-up to confirm benignancy? And at what intervals?
Bosniak IIF (“F” for follow-up). Follow-up at 3, 6, 12 months (Dunnick: 6 mos and repeated at 1-yr intervals)
(Dunnick) What Bosniak category are intrarenal or large (>3 cm) hyperdense cysts?
IIF
What renal lesions are classified under Bosniak III?
Multilocular cystic nephroma, multilocular clear cell RCC, complex benign hemorrhagic or chronically infected cysts
Pyelonephritis with liquefactive necrosis results in this renal pathology?
Renal abscess
Why is the size of a renal abscess an important determinant for treatment?
Small (<2cm) - antibiotics; Large (>2cm) - requires drainage
What benign renal lesion is indistinguishable from multicystic RCC and requires surgical excision to confirm diagnosis?
Multilocular cystic nephroma - benign but Bosniak III-IV, varisized non-communicating cysts, +septations of varying thickness, +thick capsule
What pancreatic cysts are seen in vHL disease?
serous cystadenomas
Single most important criterion for distinguishing benign cystic renal masses from vascular solid lesions
enhancement
What refers to dysplastic dilatation of the collecting tubules in the papilla?
medullary sponge kidney
In which renal pole are milk of calcium cysts more common?
upper
Entities associated with congenital hepatic fibrosis
infantile/AR polycystic kidney disease, adult polycystic disease, multicystic dysplastic kidneys, choledochal cyst, and Caroli disease
What renal lesion has a characteristic feature of herniating into the renal pelvis?
multilocular cystic nephroma
Which of the phakomatoses are associated with renal cysts?
tuberous sclerosis and vHL disease
Cysts arising in the renal sinus?
peripelvic cyst (typically small, multiple, and often bilateral)
Cortical cysts projecting into the renal sinus?
parapelvic cyst (usually large but solitary)
What condition should you consider in the presence of multiple cysts in both renal sinus and parenchyma?
renal lymphangiomatosis
Classification of congenital renal AVMs
cirsoid - multiple small AV communications; aneurysmal - solitary communication
(In Brant, sabi na other term ng congenital AVM iyong cirsoid)
Findings are same with XGP but instead of hydronephrosis, there is marked proliferation of renal sinus fat?
replacement lipomatosis
What is the hallmark of reflux nephropathy of childhood and chronic pyelonephritis?
focal cortical scar that overlies a blunted calyx
What are the hallmarks of renal TB?
papillary necrosis, parenchymal destruction, and cavity formation
(Dunnick) Hallmark of renal TB
multiple irregular infundibular stenoses/strictures with subsequent hydrocalycosis
In which pole do parenchymal scars in chronic pyelonephritis more commonly occur?
upper pole
(Dunnick) Stones radiolucent on plain radiographs
uric acid, xanthine, matrix, pure struvite, protease inhibitor such as indinavir (Note: sa brant, radiopaque si struvite)
Triad of findings in xanthogranulomatous pyelonephritis?
staghorn calculus, absent/diminished excretion of contrast, poorly defined renal mass
The only calculi that are not high attenuation on noncontrast CT
indinavir (antiretroviral for HIV patients)
Causes of medullary nephrocalcinosis
hyperpara, medullary sponge kidney, RTA, milk-alkali syndrome, hypervit D, hypercalcemia/hypercalciuria
Causes of hypercalciuria
Increased absorption - hypervitaminosis D, milk-alkali syndrome, sarcoidosis, berylium poisoning, idiopathic hypercalciuria
Increased mobilization from bone - hyperpara, immobilization, bone mets, multiple myeloma, hyperthyroidism, Cushing syndrome
Decreased tubular reabsorption - RTA, Fanconi syndrome, Wilson disease, amphotericin B
Diseases processes that cause secondary RTA (impairing H+ excretion by the distal tubule)
Fanconi syndrome, Wilson disease, amphotericin B toxicity
Medullary nephrocalcinosis is usually bilateral. Which condition is an exception?
medullary sponge kidney (may be unilateral or segmental)
Major causes of medullary nephrocalcinosis
RTA type I (distal), hypercalcemic states, medullary sponge kidney
Earliest sign of acute ureteral obstruction
effacement of the paracalyceal fat
Rule of 7’s
70% of stones <7 mm will pass spontaneously
What drug predisposes xanthine stone formation?
allopurinol
Hallmark of a circumcaval ureter
severe medial deviation
Least dense stones
uric acid (150-500)
In complete ureteral duplication, UPJ obstruction is a complication of which pole?
lower (due to reflux?)
Most dense stones
CaOx stones (800-1000HU)
Secondary signs of ureteral stone on CT
perrinephric stranding/fluid, periureteral edema, enlarged kidney, hydoureter/hydronephrosis
Course of ureter and gonadal vein
level of renal hilum - ureter is medial to gonadal vein
pelvis - they cross so that ureter is lateral to the vein
gonadal vein is somewhat more anterior than ureter
Where does the ureter draining the upper pole insert in relation to the normally placed ureter?
infero-medial
Diameter of dilated ureter
> 3 mm
IVC anomaly in retrocaval/circumcaval ureter?
persistence of the right subcardinal vein anterior to the ureter instead of the right supracardinal vein posterior to the ureter
Which anomaly is virtually associated with all ectopic ureteroceles?
complete duplication
Measurement of thickened wall of the renal collecting system?
> 2 mm
VUR grading
I - ureter / distal ureter
II - collecting system without dilation
III - collecting system with mild dilation - mild blunting of the calyces
IV - collecting system with moderate diilation - marked hydroureter and greater degree of dilatation/blunting of the calcyces
V - collecting system with severe dilation - marked tortuosity and dilatation of the ureter
What appearance represents a slightly dilated segment of the middle 1/3 of the ureter superior to the crossing iliac vessels?
ureteral spindle
Ureteral course
-L1-L2 interspace - leaves the kidney through the hilus
-proximal ureter lies lateral, anterior, and then medial to the psoas muscle as it descends
-L4 to L5 - leaves Gerota fascia and crosses anterior to the common iliac artery
-true pelvis / level of iliac spine - gentle posterolateral course
-runs anteromedially to enter UB
What should be the primary diagnosis when strictures are seen at multiple levels throughtout the intrarenal collecting system and ureter?
TB
l system or ureter In what location is leukoplakia premalignant?
UB (not premalignant in the ureter)
Possible etiologies of papillary necrosis
Acronym: NSAID
N-SAIDs
S-ickle cell
A-nalgesic nephropathy
I-nfection (especially TB) D-M
