Fibrous lipoblastoma with 8q11.2 abnormality

A 3-month-old African American female infant had a rapidly growing lipoblastoma with a prominent fibrous component in the soft tissue of the left lateral knee, which recurred at 10 months. Cytogenetic analysis revealed deletion of 8(q11.2q13) with a 19(q12q13.3) insertion at that site, confirming that this is closely related to the conventional lipoblastoma. The presence of multivacuolated lipoblasts and the staining characteristics (no staining for CD99, CD34, or smooth muscle actin) distinguish this from the recently described lipofibromatosis.