CLINICAL HISTORY.—This 11-month-old boy was brought to the hospital because of lack of appetite, loss of weight, and an abdominal mass. The mother stated that she first noted enlargement of the abdomen one month earlier. No other symptoms were present.
A large mass was palpable in the left flank and extended into the iliac fossa. There were no other abnormal physical findings. An anemia was present with an erythrocyte count of 2,720,000/cu mm and hemoglobin determination of 50%.
Denouement and Discussion
Retroperitoneal Spindle Cell Sarcoma
The plain roentgenograms of the abdomen show a soft tissue mass in the left flank displacing the intestine to the right. There are no calcifications. On excretory urography (Fig 1), contrast is seen in the mass on the left, and there appear to be two superimposed renal collecting structures to the right of the spine. In the lateral projection (Fig 2), the collecting structures of