Download Radiologic Diagnosis of Wilms Tumor

Radiologic Diagnosis of Wilms Tumor
Adam Friedman
Gillian Lieberman, MD
March 2008
Patient presentation
• Two year old male with abdominal pain, swelling
and constipation.
Our patient: RUQ mass on abdominal plain film
Study: Abdominal X-Ray
Findings:
• Dilated large and small
bowel, leftward
displacement
• Soft tissue density in
right upper and lower
abdomen obscuring
lower liver margin
Our patient: Heterogeneous mass on ultrasound
Study: RUQ ultrasound
Findings:
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Heterogeneous, septated, soft tissue mass, 9 x 10 x 6cm, with solid
and cystic components (anechoic regions with enhanced throughtransmission).
Doppler demonstrates regions of vascular flow in addition to cystic
elements
Differential diagnosis
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Wilms Tumor
Neuroblastoma
Hepatoblastoma
Nephrogenic rests or nephroblastomatosis (multifocal
or diffusely bilateral nephroblast remnants)
• Other abdominal soft tissue masses:
– Rhabdomyosarcoma
– Lymphoma
– renal cell carcinoma (adults)
Our patient: Heterogeneous mass on axial CT
mass
r. kidney
l. kidney
Our patient: Heterogeneous mass on coronal CT
mass
spleen
l. kidney
r. kidney
Our patient: Summary of findings on CT
Study: Abdominal CT with oral and IV contrast, late arterial phase
Findings:
• 10.5 x 9.3 x 12.2 cm cystic heterogeneous mass within the right hemiabdomen,
originating from upper/middle poles of kidney
• Mass-effect shift of liver
• Narrowing and deviation of infrahepatic IVC
• “Claw sign” of engulfment by right kidney
• No evidence of renal vein or IVC thrombosis
• No evidence of pulmonary metastatic disease
Diagnosis: Wilms Tumor
• Wilms Tumor, with cystic elements and favorable
histology.
• Stage III due to lymph node metastases and tumor
rupture noted intra-operatively, with adherent liver
metastases
Radiologic features of Wilms Tumor
• “Claw Sign”: Concavity of the renal contour
with renal parenchyma cupping the tumor/cyst
• Clawing suggests organ of tumor origin.
• Major differential is neuroblastoma, a neuroendocrine
tumor of neural crest origin):
• Neuroblastoma: Displacement of kidney, adrenal origin, encasement
of IVC/aorta, 90% calcifications
• Wilms: Engulfment of kidney, origin from renal parenchyma,
displacement of vessels, 15% calcification
Neuroblastoma vs. Wilms Tumor
companion patient #1
companion patient #2
companion patients #3-4
Neuroblastoma
Wilms Tumor
Displacement of kidney
adrenal origin
encasement of IVC/aorta
90% calcifications
engulfment of kidney
origin from renal parenchyma
displacement of vessels
15% calcification
Wilms Tumor: embryology, epidemiology, biology
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Derived from remnant rests of embryonic nephroblastic cells
Associated with WT1 transcription factor tumor suppressor
6% of all childhood cancers, 1:10,000 incidence, with peak incidence between 2-5
Cure rates ~85%
Associated syndromes include (WAGR), Beckwith-Wiedemann, Denys-Drash,
horseshoe kidney
5% bilateral, 5% metastatic (lung, lymph nodes, liver); 6% extend into IVC or RV
Nephrogenic rests (intralobar or perilobar) increase risk for WT (but only ~1%)
Histologically: blastemal, stromal, epithelial cells
Wilms Tumor: the role of imaging
• Ultrasound: Hypervascular, heterogenous mass
• CT: solid, heterogenously enhancing, solitary renal mass
(can be bilateral); calcifications in <20%
• MRI: Hypointense on T1, hyperintense on T2, with
heterogeneous enhancement
• CT used for staging due to superior resolution of lung
metastases (vs. bone scanning for neuroblastoma)
• U/S monitoring of high risk (syndromic) patients every 3-4
mo until 7 yo
Wilms Tumor: staging and therapy
• Staging:
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I - Unilateral, intact renal capsule, total excision
II - Regional tumor extension, total excision
III - Residual tumor, confined to abdomen
IV - Metastases (lung, liver, bone, brain)
V - Bilateral
• Treatment:
• Nephrectomy (if IVC not involved)
• Chemotherapy (vincristine/actinomycin D, +/- doxorubicin, etoposide,
carboplatin)
• Preoperative chemotherapy in Europe for down-staging, vs. post-op in
US.
• Radiation (<30%)
• Routine U/S monitoring
Advanced imaging modalities in Wilms Tumor
• 3D MRI tumor perfusion mapping
• DWI/ADC MRI mapping
• FDG-PET/CT
Preoperative 3D mapping of tumor perfusion
companion patient #5
• Maximum contrast (absolute) or maximum slope of
contrast enhancement during MRI used to correlate areas
of necrosis and perfusion of nephroblastomas or
neurblastomas for surgical planning.
Apparent diffusion coefficient (ADC) mapping
companion patient #6
• Contrast-enhanced T1 MRI vs. ADC map
• Rim-enhancement and interior architecture prominent with
ADC map
• ADC mapping may indicate early tumor response, before
clear tumor shrinkage (late finding)
FDG-PET/CT
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Companion patient #6 with renal cell carcinoma
18F-fluorodeoxyglucose positron emission tomography (FDG-PET)
imaging reveals areas of increased metabolic activity
Developing utility in Wilms Tumor:
• Targeting biopsy to most aggressive elements
• Monitoring treatment response
• Identification of metastatic lung foci
Summary
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Discussion of 2 y.o. boy with Stage III Wilms Tumor
Radiologic diagnosis of WT vs. neuroblastoma
Utility of “claw sign”
Review of Wilms Tumor embryology, biology
Advanced radiologic tools for WT diagnosis and tracking
Acknowledgments and References
Acknowledgments:
• Jay Pahade, M.D.
• Gillian Lieberman, M.D.
References:
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Kaste SC, McCarville MB. (2008) “Imaging pediatric abdominal tumors.” Semin Roentgenol., 43(1): 50-9.
Günther, P, et al. (2008) “3D Perfusion Mapping and Virtual Surgical Planning in the Treatment of Pediatric
Embryonal Abdominal Tumors,” Eur J Pediatr Surg. 18(1):7-12.
University Hospitals of Cleveland, www.uhrad.com, 2008.
Owens, CM, et al. (2008) “Bilateral disease and new trends in Wilms tumour.” Pediatr Radiol., 38(1): 30-9.
Kaste SC, et al. (2008) “Wilms tumour: prognostic factors, staging, therapy and late effects.” Pediatr Radiol., 38(1): 217.
Ros, P. (eds), Mortele, K., Pelsser, V., Lee, S. (2007) CT And MRI of the Abdomen And Pelvis: A Teaching File,
Lippincott Williams & Wilkins
Olsen, OE and Sebire, NJ (2006). “Apparent diffusion coefficient maps of paediatric mass lesions with free-breathing
diffusion-weighted magnetic resonance: feasibility study.” Acta Radiol, 47:198–204.
Schedl (2007). “Renal abnormalities and their developmental origin.” Nat. Rev. Gen., 8: 791-802.
Eubank, WB, et al. (1998). “Imaging of oncologic patients: benefit of combined CT and FDG PET in the diagnosis of
malignancy.” AJR Am J Roentgenol., 171(4): 1103-10.