Clinical outcomes of deep atypical lipomas (well-differentiated lipoma-like liposarcomas) of the extremities

Aim: Controversy exists with regard to the nomenclature, treatment and outcome of a group of well-differentiated lipomatous tumours sometimes labelled as atypical lipomas. The purpose of the present paper is to attempt to clarify these controversies by reporting our experience with this lesion. Methods: The clinical features and follow up of 61 patients with the diagnosis of deep atypical lipoma and a minimum two-year follow up were examined. Results: All patients were treated by marginal excision alone. A local recurrence was seen in five patients (8%). Three recurred once and two recurred twice. No patient had a metastasis or died as a result of the tumour. No lesion dedifferentiated. Conclusion: We believe the term atypical lipoma is appropriate for these tumours, as they appear not to have any metastatic potential, merely a propensity to recur locally. The chance of dedifferentiation is small and radiotherapy may play a role in its causation. We suggest that a simple marginal resection (shelling-out) is adequate treatment for these lesions. Radiotherapy should not be used.