RESUMO
INTRODUCTION: Lipoblastomas are benign tumors that arise from the proliferation of fetal adipose tissue. They are frequently found in the extremities, in the head, and in the neck. Dumbbell conformation (which refers to epidural tumors with extraspinal extension) has been described in only seven lipoblastoma cases so far. CASE REPORT: We describe an 11-month-old patient with a large mediastinal dumbbell lipoblastoma. The mass was excised, but it recurred 1 year later when the MRI showed also multiple pleural lipoblastomatous lesions, thus establishing the diagnosis of lipoblastomatosis. The tumor has been removed with a second surgical procedure. CONCLUSION: Radical excision of lipoblastomas is the gold standard but is not always possible to achieve. Residual lesions can be managed conservatively, on the basis of the benign nature of the tumor and of its potential maturation to normal fat. Recurrence of lipoblastoma appears in 15 % of non-radical excisions but has not yet been described in the form of lipoblastomatosis. A second surgery is indicated if the tumor mass reaches large dimensions, if it increases in size, and if it threatens the functionality of vital organs such as the spinal cord.