Visual presentation of the staging of pediatric solid tumors.

Staging systems are used in staging most pediatric solid tumors outside the central nervous system. Common solid, nonneurologic pediatric tumors include liver tumors, Hodgkin disease, non-Hodgkin lymphoma, Wilms tumor, rhabdomyosarcoma, neuroblastoma, Ewing sarcoma, and osteosarcoma. Traditional staging of pediatric tumors depends on the anatomic distribution of the malignant disease. Almost all staging systems are based on the spread of the local primary tumor, metastasis to regional lymph nodes, and distant blood-borne metastatic spread. There is some variability as to how tumor spread is assessed. Such assessment may be performed before or after surgery. There are many potential problems with tumor staging systems. The systems vary in complexity and clinical usefulness, and there is some variation in the criteria used in the different systems. It is important for radiologists to have a sound working knowledge of staging systems to facilitate accurate staging. Imaging is an important aspect of every staging system.

Renal pseudotumor due to aberrant renal capsular artery supplying normal spleen.

A renal pseudotumor caused by a small portion of normal spleen receiving blood supply from a renal capsular artery is described. CT with nonselective enhancement and liver/spleen scan may fail to delineate this previously unreported finding. CT angiography, however, can establish the diagnosis. The consideration of this situation in the differential diagnosis may help avoid costly additional workup.