LIPOBLASTOMA AND LIPOBLASTOMATOSIS - A CLINICOPATHOLOGICAL STUDY OF 14 CASES

The clinicopathological features of 14 cases of lipoblastoma and lipob lastomatosis are presented. The age of the patients at presentation ra nged from 5 days to 6 years (mean 2.7 years); nine patients were male. Histologically, six cases were circumscribed (lipoblastoma) while eig ht were diffuse and ill-defined (lipoblastomatosis). In both groups an d in individual cases there was distinct lobulation, as well as a spec trum of adipocytic maturation. Cytologically, the 10 most mature lesio ns were composed of uniform adipocytes intermixed with only scattered lipoblasts and primitive mesenchymal cells. A notable feature in the o ther four cases was a prominent myxoid stroma producing a very close r esemblance to myxoid liposarcoma. Mitotic figures were rare and always normal in appearance. Atypical nuclei were not evident. Follow-up in eight patients revealed local recurrence in two. Liposarcoma in patien ts under 10 years is exceedingly rare, and, in myxoid form, may be alm ost impossible to distinguish histologically from lipoblastoma. Helpfu l clues are the lack of lobulation, variable growth pattern and increa sed nuclear atypia in liposarcoma.