A lawyer with a mass on the leg for 18 months

Case Identification

Case ID Number
Body region
Position within the bone
Periosteal reaction
Benign or Malignant

Clinical case information

Case presentation

A 61 year old attorney has noticed a superficial mass on the left left for about 18 months. It was totally painless but sometimes caused itching. The mass was initially thought to be a varicose vein, but slowly and progressively increased is size. On examination, a definite mass can be seen and felt.

Radiological findings:
The MRI shows a multilobular lesion apposed to the cortex of the anterior distal tibia, without obvious bony involvement, with "indeterminate" signal characteristics (low signal on T1, high signal on T2). The signal intensity is somewhat variegated within the mass, and is not consistent with a fluid-filled process such as a cyst.
Differential Diagnosis
This mass is "indeterminate" on MRI. However, the clinical and radiological features allow the potential for malignancy to be assessed in a qualitative way. What factors have a bearing on the potential for malignancy of this lesion?
Case Answer
Clinical Case Answer