July 13, 2009 | In: ABDOMINAL SURGERY
87 ABDOMINAL TUMORS
Frederick M. Karrer M.D., Denis D. Bensard M.D.
1. What are the most common malignant solid abdominal tumors in children?
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Neuroblastomas, Wilms’ tumors, and hepatoblastomas, in that order. Neuroblastomas are derived from neural crest tissue; in the abdomen, they originate from the adrenal glands and paraspinal sympathetic ganglia. Wilms’ tumor (nephroblastoma) derives from the kidney, and hepatoblastomas originate in the liver.
2. Is it tough to differentiate Wilms’ tumor from neuroblastomas clinically?
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Yes. Both tumors present as an asymptomatic abdominal mass. The differences are summarized in Table 87-1. In addition, because neuroblastomas produce hormones, affected children may exhibit flushing, hypertension (catecholamine release), watery diarrhea, periorbital ecchymosis, and abnormal ocular movements.
Table 87-1. DIFFERENTATION BETWEEN WILMS’ TUMOR AND NEUROLASTOMA
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Wilms’ Tumor
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Neuroblastoma
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Age at presentation
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3-4 yr
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1-2 yr
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Extend across midline
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Rare
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Common
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Surface on palpation
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Smooth
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Knobby
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X-ray calcifications
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No
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Yes
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3. How are Wilms’ tumors and neuroblastomas treated?
Table 87-2. TREATMENT OF WILMS’ TUMOR AND NEUROBLASTOMA
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Wilms’ Tumor
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Neuroblastoma
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Primary surgical excision
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Important (likely)
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Important (less likely)
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Chemotherapy
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Enormous impact
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Less responsive
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4. What are the major prognostic factors in neuroblastomas and Wilms’ tumor?
In neuroblastomas, age at presentation is the major prognostic factor. Children younger than 1 year have an overall survival rate > 70%, whereas the survival rate for children older than 1 year is < 35%. Shimada proposed a prognostic classification based on evaluation of histologic parameters (tumor differentiation, mitosis-karyorrhexis index [MKI]) as well as age. Aneuploid tumors, tumors with low MKI, and tumors with < 10 copies of the n-myc gene also have better outcomes.
Age is also important in children with Wilms’ tumors, but the prognosis is better because the tumors are more readily excised and much more sensitive to chemotherapy.
5. What are the differences between hepatoblastomas and hepatocellular carcinomas? How are the tumors treated?
Hepatoblastomas usually occur in infants and young children, whereas hepatocellular carcinoma usually occurs in children older than 10 years. Hepatocellular carcinoma usually is associated with cirrhosis and hepatitis B and is histologically identical to the adult form. Surgical resection is the primary therapy for both tumors. Hepatoblastomas often have a good response to adjunctive chemotherapy, whereas hepatocellular carcinoma rarely responds to chemotherapy.