Lipoblastomas are benign tumors of the embryonic lipoid cells mainly occurring in infancy and early childhood. They are clinicopathologically distinguished in two forms: the well-circumscribed and localized type and the diffuse, irregularly confined type with infiltrative growth pattern, also called lipoblastomatosis. We report two pediatric cases of a mesentery localized and cervical diffuse lipoblastomas investigated both with ultrasound and computed tomography examinations.