Transcript Renal Masses - Radiology Teaching Files

Renal Masses
Robert D. Thomas MD
Pediatric Radiology
Renal Masses
 Balls
 Cyst
 Hematoma
 Abscess
 Tumor
 Dromedary hump
 Beans
 Duplication/anomaly
 Compensatory
hypertrophy
 Hydronephrosis
 Pyelonephritis/edema
 Hematoma
 PCKD
 Tumor
 Vascular
occlusion/trauma
Renal Masses by Age
 Newborn
 Hydronephrosis
 MCDK
 AR-PCKD
 Anomalies
 Tumors


Mesoblastic
nephroma
Nephroblastomatosis
 Childhood
 Cysts
 Hydronephrosis,
MCDK
 Anomalies
 Hematoma
 Tumors
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Wilms
Lymphoma
Angiomyolipomas
Hydronephrosis
(Bean)
 Calyceal/Pelvic obstruction
 Congenital (intrinsic/extrinsic)
 TB
 Tumor
 Ureter
 Physiologic (full bladder)
 Congenital (1 megaureter, ectopic ureter,
retrocaval)
 Inflammatory (TB, Crohn, PID, etc)
 Intraluminal (stone, clot, tumor, stricture)
Congenital UPJ obstruction
 #1 cause of renal mass in newborn
 Associations
 Ipsilateral reflux
 Lower moiety of duplication
 Most common cause of obstruction with
horseshoe kidney
 Causes
 Stricture, disordered peristalsis, ischemia,
redundant urothelium, crossing vessel, etc.
Congenital UPJ obstruction
 Imaging:
 Mass in plain films
 US – dilated pelvo-calyceal system
(communicating cysts): dilatation-fluid equal to
cortical thickness
 NM – obstructive pattern w/o lasix response
 Pitfalls
 US may underestimate hydro due to
oliguria/dehydration in newborn
 MCDK may look like UPJ if only a couple cysts
present
Congenital UPJ obstruction
 Work-up
 VCUG: co-existant ipsilateral reflux*,
urethral obstruction, contralateral reflux
 Scintigraphy: site of obstruction & renal
function
 *obstruction
to reflux at UPJ, dilution of
contrast in dilated renal pelvis, delay in
drainage from renal pelvis
Multicystic Dysplastic Kidney
Bean or Ball
 Not a true “cystic disease”
 etiology is severe embryonic
obstruction during metanephric stage of
development
 So…it’s an obstruction
 Hallmark: non-function of the kidney
 Bilaterality not compatible with life due
to severe pulmonary hypoplasia
Multicystic Dysplastic Kidney
 2nd most common renal mass in newborn
 Types
 Pelvoinfundibular – atresias at ureter, pelvis,
infundibulae
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
Most common, grape-like collection of cysts and
dysplastic glomeruli, atrophied tubules
Hydronephrotic-atresia of proximal ureter alone

Uncommon (5%)
Multicystic Dysplastic Kidney
 Imaging
 US
- Isolated cysts without a definable
pelvis and without normal renal tissue
 IVP – lack of function
 NM – absence of perfusion & lack of
function (may have minimal activity 2448hrs)
Multicystic Dysplastic Kidney
 Work-up
 US: frequent contralateral UPJ, reflux,
 VCUG: opposite reflux/obstruction
 MAG3, DTPA renogram
 Management
 Usually observation (natural history of involution)
 Nephrectomy for GI obstruction/respiratory
compromise, hypertension
 ?malignancy probably not increased over baseline
Solid Renal Masses
Beans and Balls!
 Hematoma
 Abscess
 Tumor
R/P mass in Neonate
 Renal
 Hydronephrosis
 Multicystic dysplastic kidney
 Solid
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Wilms tumor?
Perinephric hematoma?
Mesoblastic nephroma?
Lymphoma?
 Adrenal
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Hemorrhage
neuroblastoma
Mesoblastic Nephroma
(Fetal renal hamartoma)
 Most common neonatal renal neoplasm
 Present as an asymptomatic mass
 Not Wilms tumor
Characteristics
 Benign appearing spindle cells with dysplastic
nephrons
 Large (8-30cm), arise in medulla
 Blends with normal parenchyma
 May penetrate capsule and invade locally
 Rare hypercellular forms may metastasize
Mesoblastic Nephroma
(Fetal renal hamartoma)
 Imaging
 Non-calcified
abdominal mass
 Look like uterine leiomyoma by US
 CT vascular and entrapped collecting
system excretes contrast
Mesoblastic Nephroma
(Fetal renal hamartoma)
 Management
 Nephrectomy
 No
chemo or radiation (usually no mets)
 Cellular form

Age >3months at surgery are more likely to
need chemo/radiation
Childhood Renal Tumors
 Wilms tumor & nephroblastomatosis
 Renal lymphoma/leukemia
 Renal cell carcinoma
 Multilocular cystic nephroma
 Clear cell sarcoma
 Rhabdoid tumor
 Angiomyolipoma (and tuberous sclerosis)
Wilms Tumor
 Most common solid abdominal mass in
childhood
 Most common renal malignancy in child
 8% of all childhood cancer
Wilms Tumor
 Demographics
 Male=female
 1% familial
 7.8 per 1,000,000 children
 Peaks between 2.5 to 3 years
 80% occur between 1-5 years
 Presentation
 Asymptomatic mass most common
 Other: pain, hematuria, hypertension, fever
Wilms Tumor
 Associated conditions
 8% have overgrowth disorders, genital
anomalies, aniridia
 Drash, Beckwith-Wiedemann, Soto, NF,
KTW, Bloom, WAGR, 45X, etc
 5% bilateral & higher incidence of above
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These children’s siblings have a 30% chance of
development of Wilms
 Nephroblastomatosis
(Wilms precursor)
Wilms Tumor
 Nephroblastoma (Wilms “in situ”)
 Rests of metanephric blastema persisting after 3436 weeks gestational age
 Present in most cases of bilateral Wilms, 15%
unilateral disease
 Intralobular NR
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Younger age
Drash & sporadic aniridia
Metachronous Wilms
Perilobular NR
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BWS, Tr18, hemihypertrophy
Synchronous Wilms
Wilms Tumor
 Nephroblastomatosis
 ImagingAppearance
Nodules
 Subcapsular hypodense plaques

– iso, hypo, hyperechoic (relatively
insensitive)
 CT w contrast better for surveillance
 MRI ? Able to distinguish Wilms from
nephroblastomatosis
 US
NR versus Wilms at MRI
 NR
 Plaque-like
 Ovoid
 Lenticular
 Homogeneous on all
sequences
 Hypotense post gad
 Wilms
 Round/spherical
 Heterogeneous pre
gad
 Heterogeneous post
contrast
Nephroblastomatosis
 Treatment
 Confluent
disease treated with
chemotherapy
Wilms Tumor
 Pathology
 Solid, necrosis, hemorrhage, 15%
calcifications
 Capsule usually intact
 Invades nodes, veins, rarely urothelium
 Decreasing 10’s

10% renal vein invasion
– 10% IVC extension
• 10% right atrial extension
Wilms Tumor
 Pathology
 5%
bilateral
 7% unilateral and multicentric
 Metachronous cases may occur up to 10
years later
 10% unfavorable histology
Wilms Tumor
 Pathology
 Lung
mets up to 20% at diagnosis
 Liver mets 10% of patients
 Bone mets rare (lytic)
 Bilateral tumors may have different grades
of histology (favorable vs unfavorable)
Wilms Tumor
 Staging
– limited to kidney, completely resected
 II- outside kidney, completely resected
 III – confined to abdomen
 IV – hematogenous mets
 V – bilateral initial/during treatment
I
Wilms Tumor - Radiology
 Nitwits (NWTS) don’t agree on optimal
imaging – nonsense like IVP’s persist
 IVP – distortion of collecting system, nonfunction (vascular compression)
 US –
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CDS excellent for venous tumor thrombi in IVC
Echotexture similar to liver
Sharply marginated
Wilms Tumor - Radiology
 CT
 15%
contain calcifications
 Round, hetergeneous, low density
 Displaces vessels, does NOT encase
(DDX from neuroblastoma)
 Best for opposite kidney evaluation, nodes,
lungs
Wilms Tumor-Radiology
 MRI
 Becoming
preferred over CT
 Prolonged T1 and T2, heterogeneous post
gad
 Excellent for NR of 4 mm size
 Angio
 Plays
a role for partial nephrectomy
Wilms Tumor - Surveillance
 Patients with syndromes associated
with Wilms
 US easiest, MRI may be best
 Arbitrary 3-6 month scans
 Continue until about 10 years old (<1%
incidence after 10)
Wilms Tumor - Treatment
 Overall survival now 90%
 >90%
survival @ 2 yrs with favorable
histology, surgery, chemo and radiation
 High mortality with unfavorable histology
Renal Lymphoma
 Usually late in NHL
 Nodules, masses, diffuse infiltration
 Unilateral/bilateral
 US – hypoechoic
 CT – hypodense
 Leukemia usually diffuse/bilateral
Multilocular Cystic Nephroma
 Indistinguishable from cystic partially
differentiated nephroblastoma/cystic
Wilms
 Young boys and adult women
 Anechoic cysts with regular septa
 Rx - nephrectomy
Clear Cell Sarcoma
 Identical age group to Wilms
 Very aggressive
 Not distinguishable from Wilms by
imaging
 Bone mets common
Other lesions to ponder
 “Simple” cyst
 Were
considered rare prior to ultrasound
 But, the differential diagnosis is:
Prior trauma or infection
 Obstructed upper pole moiety of duplication
 Early presentation of familial cystic disease
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Other lesions to ponder
 Duplication
 Hematoma/renal trauma
 Pyelonephritis
 Focal bacterial
 Xanthogranulomatous
 Autosomal recessive polycystic kidney
dz
 Infantile
form