Pediatric lipoblastomatosis: two unusual cases.

Lipoblastomatosis is a rare, fatty tumor of childhood that is usually located in the limbs. Two pediatric patients were seen with tumors that originated in the mediastinum and retroperitoneal area. The mediastinal tumor was the infiltrating form of lipoblastomatosis while the retroperitoneal tumor was the noninfiltrating type. Neither form is malignant but local recurrences are common. Both were surgically excised without sacrifice of important contiguous structures that were surrounded by tumor. There has been no recurrence 21/2 and 6 years after operation. Conservative excision of this malignant-appearing but histologically benign tumor is emphasized.