[Lipoblastoma: the least well known of adipose tumors]

Lipoblastoma is the least known of adipose tumours. It comes from embryonic adipose tissue and though it is histologically benign, it is locally invasive, implying a high risk of relapse if it is incompletely removed. The pediatric surgeon should be familiar with this tumor since it usually appears in children under three.

A retrospective study of the patients who were operated upon at our institution with a histologic diagnosis of lipoblastoma from 1966 to 2002 taking into account: age, tumor site, cytogenetic studies, first diagnosis, treatment and clinical course.

The diagnosis of lipoblastoma was carried out in six patients (three boys and three girls). All were diagnosed before the first year of life and one was present at birth. In only one case the diagnosis was pre-operative. Two tumors were thoracic, two paravertebral with an intrarachidian component without spinal cord involvement (one of them was associated with myelomeningocele and diatomyelia), two in limbs and one perineal. A girl operated for the first time at four months, was latter operated in four opportunities for a relapse. In the last operation the excision was incomplete due to a subclavian involvement; in the last 15 years no new tumor growth was seen. After a follow-up period of 1 to 25 years in the other six patients no relapse was observed.

Despite its low frequency, the diagnosis of lipoblastoma must be considered in children with masses in soft tissue, mainly if they are younger then one year. Because the lipoblastoma is locally invasive, this tumor must be treated before it affects viscera. The resection must be complete, avoiding the risk of relapse, although radical mutilating surgery is not recommended.