Natural History Study of Infants With Adrenal Masses Found on Prenatal and/or Neonatal Imaging

Inclusion Criteria: * Sonographically identified adrenal mass meeting one of the following criteria: * No greater than 16 mL in volume, if solid * No greater than 65 mL if at least 25% cystic and does not cross the midline * Disease limited to the adrenal gland * No evidence of positive contralateral or ipsilateral lymph nodes or other spread outside the adrenal gland by CT scan or MRI * No evidence of disease outside the adrenal gland by MIBG scan * Negative for tumor cells by bone marrow biopsy, if performed * No more than 6 months of age on the date the mass is first identified * No prior chemotherapy * No prior abdominal surgery