Lipoblastornatous tumors are quite rare neoplasms deriving from embryonic white fatty tissues, most often seen in infancy and childhood. Lipobtastoma is the focal and well-circumscribed type, whereas tipoblastomatosis is the more infiltrating type of lipoblastomatous tumors. We present a 14-month-otd mate infant presenting with a mediastinal mass showing paraparesis, who had previously undergone the removal of the cervical part of this mediastinal mass. We removed the mediastinal part of the mass with a posterotateral thoracotomy which proved to be a tipobtastomatosis. We emphasize that this very uncommon tumor located at the neck and mediastinum should be included in the differential diagnosis of infants having gait disturbance. (c) 2007 European Association for Cardio-Thoracic Surgery. Published by Elsevier B.V. All rights reserved.