Case study Renal block Dr Willie Conradie May 2012 Diagnostic Radiology

4yr old boy from Lesotho O Weight loss O Normal “Mile-stones” O No chronic disease O Resp:No coughing. No TB history O GIT: No nausea/vomiting/diarhoea. O Uro: Normal frequency and colour O Exam:Right sided abdominal mass..

Nephroblastoma vs Neuroblastoma?

Nephroblastoma (Wilms’ tumor) O Incidence O Most common malignant abdominal neoplasm in children (1-8 years) O 3 rd most common malignancy in children O Leukemia O CNS tumors O 3 rd most common renal mass in children O Hydronephrosis O Multi-cystic dysplastic kidney O 7% of all childhood Ca

Wilms tumor O Familial in 1-2% O M=F O More common in blacks O Peak age at 3-4 years O 90% before 8 years O Rare in neonates and adults O Undifferentiated metanephric blastema (persistant primitive renal parenchyma) O “nephrogenic rests” O Multiple foci = Nephroblastomatosis O Genetic: O Abnormal WT1 (11p13) - WAGR/DRASH O Abnormal WT2 (11p15) - Beckwith-Wiedemann - Hemihypertrophy Rule of 10’s: 10% unfavourable histology 10% bilateral 10% vascular invasion 10% calcifications 10% pulmonary metastases at presentation 10% metastasize to liver

O CT O Poorly enhancing mass O Well-defined margins or pseudocapsule O Local extension into perirenal fat and local lymph nodes Wilms tumor Best diagnostic clue: Large heterogeneous mass Replacing/in kidney Displacement of organs/vessels Extending into renal vein and IVC Calcifications less often seen

Wilms tumor O MR Findings O TlWl: Typically low signal intensity on Tl O T2Wl: High signal on T2 O heterogeneous and O frequently containing blood products O MRA: useful in determining vascular spread pre-operatively O Nuclear medicine O Bone Scan: O Metastatic disease to bone occurs very late; O Not routine O PET O Increasing use in Wilms and all pediatric tumors O Primarily has an adjunctive, problem solving role O Differentiating scar tissue from residual active tumor

Neuroblastoma O Incidence O 3 rd most common malignant tumor in infancy O Leukemia O CNS O Most common tumor in first week of life O Most common solid, extra-cranial malignant tumor in children O 8-10% of all childhood Ca O 15 % of cancer deaths in children

Neuroblastoma O Mean age at diagnosis = 22 months O 36% are infants O 89% < 5years O 98% <10 years O M:V = 1.1:1 O Malignant tumor of primitive neural crest cells O Location O Adrenal glands/para-vertebral sympathetic ganglia (70%) O Posterior mediastinum (20%) O Pelvis (2-5%) O Neck (1-5%)

O MRI O High on T2WI;Low on T1WI O Heterogeneous - related to calcification/hemorrhage/necrosis O Excellent for detecting extension of tumor into spinal canal. Neuroblastoma Best diagnostic clue: Invasive heterogeneous suprarenal mass Calcifications (85%) Crosses midline Rather surrounds and engulfs vasculature Tendency to invade spinal canal (via neuroforamina) Metastasizes commonly to bone, liver and LN

Neuroblastoma O Nuclear medicine O Bone Scan O Technetium-99m MDP O Uptake seen in bony metastasis (both cortical and marrow) O Calcified primary mass often also demonstrated uptake (up to74% of cases) O MIBG O Metaiodobenzylguanidine O Avid uptake related to catecholamine production O Excellent for following extent of disease in MIBG avid tumors O 30% of neuroblastoma are not MIBG avid

STAGE I- Limited to organ of origin II- Regional spread not crossing midline III- Extension across midline IV- Metasteses IVs- I or II with disease limited to liver, skin, BM WITHOUT radiographic evidence of bone metasteses. Neuroblastoma

References 1. Siegel MJ, Chung EM. Wilms’ tumor and other pediatric renal masses. Magn Reson Imaging Clin N Am 16 (2008): Siegel MJ, AlokJaju. MR Imaging of Neuroblastic masses. Magn Reson Imaging Clin N Am 16 (2008): Donnely et al. Diagnostic Imaging: Pediatrics. First edition. 5:50-53; 5: Dahnert W. Radiology Review Manual. Sixth edition: ;