Myxoid Chondrosarcoma

Clinical History: 
This 65-year-old man presented to clinic with a tender mass in the anteromedial portion of his right midthigh which had enlarged over a year’s time. He further complained of nonspecific associated symptoms, including paresthesias and occasional temperature changes in his right leg. Following the illustrated MR examination, the patient was referred for evaluation by surgical oncology.

Diagnosis:
Myxoid Chondrosarcoma

MR Technique: 
Scans were acquired on a 1.5 T Siemens MR unit. (A) Coronal pre-contrast spin echo T1-weighted (TR/TE 604/13 ms, scan time 2:24 min:sec) images as well as (B) coronal turbo spin echo fat-suppressed T2-weighted (TR/TE 4230/74 ms, scan time 2:28 min:sec) images were obtained, in addition to (C) sagittal post-contrast spin echo fat-saturated T1-weighted images. The slice thickness was 5 mm in each instance.

Imaging Findings:
A mildly lobulated mass measuring 5.2 cm in greatest dimension is identified within the vastus medialis muscle, abutting the sartorius and displacing the superficial femoral neurovascular bundle. A thin fat plane between the mass and the superficial femoral neurovascular bundle remains. The well-defined mass demonstrates heterogeneous enhancement after contrast administration.