Lipoblastoma and lipoblastomatosis are rare benign fatty tumours that mainly occur in children under the age of 3 years. Several body sites can be affected. The term 'lipoblastoma' is reserved for an encapsulated neoplasm; 'lipoblastomatosis' for tumours demonstrating infiltrative growth. Most of the clinical symptoms arise from a mass effect of the tumour on surrounding tissues. The tumours should be differentiated from lipoma, myxoid liposarcoma and hibernoma. A clear distinction can be made by cytogenetic analysis, since each of these tumours is known for its own typical genetic abnormalities. In lipoblastoma and lipoblastomatosis, these include a breakpoint in the 8q11-13 region or polysomy of chromosome 8, both leading to the activation of the oncogenic pleomorphic adenoma gene 1 (PLAG1) on 8q12. Treatment consists of surgical resection; there is no need for radiotherapy or chemotherapy. Clinical outcome depends on the completeness of the resection and damage that is done to the surrounding tissues during surgery.