Myolipoma

Rare benign lipomatous lesion
Meis and Enzinger (1991)
50-60 years with female predilection
(2:1 ratio)
Commonly seen in abdominal cavity, retroperitoneum, inguinal areas
Most are large at presentation (10-25 cm)
Imaging shows lipid and non-lipid areas of smooth muscle. Coarse calcification may be seen especially if the lesion is large; but is also a feature of well-differentiated liposarcoma.
Surgicallt resected. No reports of local recurrence or malignant change

References:
Murphey MD et al. Benign Musculoskeletal Lipomatous Lesions. RadioGraphics 2004;24:1433-1466