Non-Radiographic Risk Factors Differentiating Atypical Lipomatous Tumors from Lipomas

Purpose: To determine non-radiographic risk factors differentiating atypical lipomatous tumors (ALTs) from lipomas.Methods: All patients with deep-seated lipomatous tumors of the extremities treated from January 2000 to October 2010 were retrospectively reviewed. Factors reviewed included age, gender, tumor location, size, histology, local recurrence, dedifferentiation and metastasis. Multivariate logistic regression models were used to evaluate the effects of patient characteristics on ALT status.Results: Ninety-four lipomas and 46 ALTs were included. Patients with an ALT were older (median: 60.5 years versus 55 years). Lipomas were evenly distributed between upper (48.9%) and lower extremities (51.1%), whereas ALTs predominately involved the lower extremities (91.3%). Median ALT size (22cm) was greater than lipomas (10cm), p