Lipoblastoma and liposarcoma in children: An analysis of 9 cases and a review of the literature

OBJECTIVES: To review the experience at a children's hospital of lipoblasto ma and liposarcoma and to identify any factors that would differentiate one type of tumour from the other. DESIGN: A retrospective case series. SETTING: British Columbia's Children's Hospital a tertiary-care pediatric c entre. PATIENTS: All patients with a pathological diagnosis of lipoblastoma and li posarcoma recorded over 12 years. MAIN OUTCOME MEASURES: The frequency of lipoblastoma and liposarcoma, ident ified from biopsy specimens of pediatric adipose tumours. The clinical, pat hological and cytogenetic variables between lipoblastoma and liposarcoma. RESULTS: One hundred and forty-nine adipose tumours were recorded. Seven (4 .7%) were lipoblastomas and 2 (1.3%) were liposarcomas. All tumours present ed as asymptomatic, slow-growing, soft-tissue masses. The children with lip oblastoma tended to be younger, but 29% were over 3 years of age. The lipos arcoma patients were aged 9 and 14 years. One liposarcoma was of myxoid typ e and the other was a round cell variant, Karyotypes were reported for 1 li poblast oma and 1 liposarcoma. The myxoid liposarcoma karyotype was 46,XY,t (12;16)(q13;p11), and the lipoblastoma was reported as 46,XY,der(8)?t(8q;?) ,+mar. CONCLUSIONS: Lipoblastoma is an unusual childhood neoplasm and liposarcoma is very rare in children. Both tumours may present in a similar fashion, an d differentiating them histologically can be difficult. Age cannot be relie d upon to accurately predict their behaviour. The tumour karyotype is very helpful in differentiating these neoplasms.