Lipoblastoma and lipoblastomatosis: a report of two cases and review of the literature.

Lipoblastoma and lipoblastomatosis are rare benign neoplasms of foetal white fat tissue that occur almost exclusively in infants and children. Two cases are reported and a review of the literature is given. An almost one-year-old girl and a full-term male infant were brought to our hospital with a solid mass in the right thigh. Nine months after total excision of the lipoblastoma, the little girl developed tumour recurrence, with unexpected histopathological maturation. In the case of the little boy, lipoblastomatosis with infiltration of the surrounding muscles, together with involvement of the sciatic and posterior femoral cutaneous nerves was found. Histologically, the tumour showed an unusual inflammatory reaction. The diagnosis of this tumour was made by the pathologist, but the histopathological picture bears a striking similarity to myxoid liposarcoma, and may be indistinguishable. Recent studies describe rearrangements of chromosome 8 q11-q13 region as a new discriminative marker that distinguishes lipoblastoma and lipoblastomatosis from myxoid liposarcoma.