Delayed tumor resection in a 5-year-old child with bilateral Wilms tumor
A normally developed 5-year-old girl presented to the emergency department with a 1 month history of worsening abdominal pain that localized to the right upper quadrant with intermittent vomiting and fevers over the week prior to presentation. On physical examination, the child was febrile to 37.6°C with abdominal distension. A tender right-sided abdominal mass was found extending from the costal margin to the pelvis and beyond midline. Bowel sounds were heard only on the left. Abdominal CT imaging identified a large mass arising from the right kidney with at least one smaller lesion in the left kidney (Fig. A). Serum WBC and electrolytes were normal, with a serum creatinine of 0.40 mg/dl and a BUN of 7 mg/dl. Chest X-ray and pulmonary CT scans were negative for malignant disease.\nThe patient was given a presumptive diagnosis of bilateral (Stage V) Wilms tumor. The family consented for her to participate in the Children's Oncology Group trial AREN0534 which called for pre-operative chemotherapy in order to facilitate nephron-sparing surgery at the time of tumor resection. A central venous catheter was placed, and neoadjuvant chemotherapy with vincristine, dactinomycin and doxorubicin was initiated. Within hours of starting her therapy, we found that lactate dehydrogenase and uric acid were both elevated (1134 U/l and 6.3 mg/dl, respectively; Fig. ). Serum potassium and phosphate were both normal. The patient's hyperuricemia was felt to be consistent with tumor lysis syndrome, and allopurinol and alkalinized fluids were administered. The hyperuricemia soon resolved, and the patient maintained normal serum creatinine, potassium and phosphorus levels throughout her hospital stay. A follow-up CT scan after 6 weeks of therapy showed a marked response to chemotherapy of the right-sided lesion (Fig. B). The left-sided mass remained stable in size. We decided to administer another 6 weeks of chemotherapy to improve her candidacy for right partial nephrectomy instead of whole nephrectomy. However, despite further tumor shrinkage, total nephrectomy eventually had to be performed for the right kidney because no clear surgical plane could be identified at the time of resection (Fig. C). Pathologic interpretation of the right- and left-sided tumors confirmed Wilms tumor in each and a focus of anaplastic disease on the right (Fig. C). 10.8 Gy of radiation to the right flank was administered because of the pathologic finding of focal anaplasia, in accordance with the AREN0534 protocol. Presently the patient is well, with good renal function and in remission, now roughly 6 months after her end of therapy.