Presentation
Body wall mass with concern for liposarcoma.
Patient Data
6 x 8.5 x 10 cm (AP X TR X CC) fat-containing mass in the right posterior flank. Few areas of mildly thickened septations and stranding; however, the predominant composition of the mass is fat. No discrete rounded soft tissue elements. The mass extends in between and displaces the 11-12th ribs, and to a lesser extent the 10th-11th ribs. No pathologic fracture. The mass distorts the posterior liver capsule and anteriorly displaces the right kidney and retroperitoneum. Loss of tissue plane between the posterior flank/abdominal wall musculature; the latter appears thinned in the areas contacting the mass.
Case Discussion
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.