This 6-month-old white female was noted to have a small, bluish lump in the soft tissues of the left flank by her father while he was bathing her. One day later the abdomen appeared enlarged, and an umbilical hernia became apparent. The child's pediatrician was able to feel a mass in the upper abdomen, and the child was referred to the Children's Hospital of Philadelphia. She was the full-term product of a spontaneous vaginal delivery, following a normal pregnancy. Her past medical history was unremarkable.
Physical examination showed a 1-cm-wide, firm mass that had a bluish hue, located in the soft tissues of the left flank. The mass did not blanch upon gentle strolung. A large, right-sided abdominal mass could be palpated readily. It appeared to be separate from the liver, which was shifted to the left beyond the midline by the mass located below it and to the right. There was no obvious hepatomegaly, the spleen could not be felt. The soft tissues of both orbits appeared to be normal.
Laboratory investigations showed a hemoglobin of 7 gm/dl and a white blood cell count of 5500 per cubic millimeter, with a normal differential. The platelet count was 99,000 per mm'. Serum electrolytes were within normal limits. The total serum bilirubin was 0.9 mg/dl, and the serum glutamic-oxalic transaminase was within normal limits. Several radiographic studies were performed.