Clinical History: 
This 56 year old man presented to clinic complaining of a mass within the musculature of his medial right thigh that had appeared approximately 5 months ago. The patient denied any associated pain or tenderness. On the illustrated MR examination, a mass was found which was confirmed as a liposarcoma by pathologic evaluation following its surgical removal

Liposarcoma (low grade)

MR Technique: 
MR images were acquired on a Siemens 3 T Trio Tim MR unit. (A) Coronal pre-contrast turbo spin echo fat-saturated T2-weighted (TR/TE 4500/77 ms, scan time 3:10 min:sec), (B) coronal spin echo T1-weighted (TR/TE 700/18 ms, scan time 3:22 min:sec, slice thickness 5 mm), and (C) coronal post-contrast spin echo fat-saturated T1-weighted images were obtained. The slice thickness was 4 mm.

Imaging Findings:
A complex-appearing, heterogeneously enhancing mass with signal intensity characteristics consistent with fat arises between the adductor brevis and adductor magnus muscles on the left, measuring approximately 11.0 x 6.4 x 8.7 cm. This well-defined, mildly lobulated mass extends superiorly between the obturator internus and externus muscles.