Large fat-containing mass in the right posterior flank has imaging features most consistent with a lipoblastoma, which is a rare benign mesenchymal tumor which occurs in infancy and early childhood. Regarding the clinical concern for liposarcoma raised by the ordering team: liposarcomas are extraordinarily rare in patients less than 10 years of age; therefore, a lesion containing fat in a young child is almost invariably a lipoblastoma1.