Atypical Lipomatous Tumor / Well-differentiated Liposarcoma

Comments:
The patient was a 55 y/o female with a 15 cm. firm mid-thigh mass of several years' duration. The specimen had a variegated appearance with firm grayish-pink sclerotic areas merging with yellow adipose tissue. The tumor shows sclerotic areas in the right half and lipoma-like areas in the upper left. Grossly and microscopically, ALT/WDL resemble lipomas but contain atypical cells with hyperchromatic nuclei.