IS Case 414: Lipoblastoma
Imaging Sciences URMC 2010
Publication Date: 2010-08-27
Abdominal radiograph showed a large mass in the lower abdomen and pelvis with displacement of the adjacent structures. CT and MRI images showed a predominately cystic lesion with some areas containing fat and some enhancing septa.
Lipoblastoma is a rare, benign mesenchymal tumor of embryonal white fat that predominately occurs in infants and children. Lipoblastomas discovered after the age of ten are rare. The term "lipoblastoma" is used when the tumor is circumscribed and the term "lipoblastomatosis" is used for a diffuse, infiltrating lesion.
The most common manifestation is an asymptomatic, painless, progressively growing mass in the superficial or subcutaneous soft tissues. However, they can occur in the trunk, neck, retroperitoneum, mediastinum and perineum. Symptoms are usually related to the mass effect caused by the tumor. These tumor tend to evolve into mature lipomas.
Imaging characteristics vary according to the extent of fat versus myxoid stroma. Lipoblastomas in younger children tend to have more myxoid component. Those occurring in older children have more fat and can appear identical to a lipoma. The myxoid stroma will enhance with contrast material. Lipoblastomas with this imaging feature are identical to myxoid liposarcomas. The best clue in differentiating the two entities is the patient's age as liposarcomas are rare in patients less than ten years of age. Therefore a lesion containing fat in a child less than 2 years of age is almost invariably a lipoblastoma, even if it has significant myxoid stroma.
- Murphey MD, Carroll JF, Flemming DJ, et al. From the archives of the AFIP: benign musculoskeletal lipomatous lesions. Radiographics. 2004 Sep-Oct;24(5):1433-66. PMID: 15939194