Lipomas are usually easy to diagnose on clinical examination. They are soft, mobile with margins that may be difficult to define. They are not usually larger than 8 cm(1). Lipomas may calcify, however, there should be suspicion of a liposarcoma especially if the patient is male, the lesion is greater than 10 cm, there is less than 75% fat, there are non-fatty areas or there are thick septae(2).

Figure 1 (above): A simple lipoma of the abdominal wall.

References:

1. Merck. The Merck Manual of Diagnosis and Therapy. 18th ed. Merck Manuals; 2006.
2. Kransdorf MJ, Bancroft LW, Peterson JJ, et al. Imaging of Fatty Tumors: Distinction of Lipoma and Well-differentiated Liposarcoma1. Radiology. 2002;224(1):99-104.