An eight months old child presented with a painless swelling on the dorsum of the left foot for the last 3 months (Fig, 1). It had been gradually increasing in size and rapidly so for the last one month. There was no other similar swelling elsewhere in the body. Regional lymphnodes were not enlarged. Fine needle aspiration cytology was suggestive of lipoma. Plain radiograph of the foot did not reveal any calcification or bony involvement. At surgery, a well circumscribed lipomatous lesion of the foot encasing the tendons was found. Histopathology was suggestive of lipoblastoma.

Fig. 1. Clinical photograph showing lipoblastoma of the left foot.

Lipoblastoma is a relatively rare tumor that occurs in infancy and early childhood and arises from embryonic white fat. The most common symptom is a painless mass with or without increasing size. The trunk, extremities, head and neck, retroperitoneum, inguinal canal, peritoneal cavity, and lung are the common tumor sites. Histopathologic examination shows a cellular neoplasm composed of immature adipocytes with relatively well-defined septa, frequent lipoblasts and a fine vascular network. Lipoblastomas are circumscribed while lipoblastomatosis is diffuse and infiltrative. It is important to completely excise the tumor to avoid leaving residual tumor and to prevent recurrences which mostly occur within 2 years. Confusion with myxoid liposarcoma, well-differentiated liposarcoma, and typical lipomas may occur.