Welcome to DoctorSpring.
I have read your query with diligence.
I have gone through report of your MRI.
It looks to be a benign tumor (Non cancerous) of fat tissue inside the muscles.
According to protocol first biopsy should be taken & if this report confirms lipoma,then this swelling /tumor can be easily removed completely. Removal of the swelling (lipoma) is optional if there is no symptoms or discomfort. You can just leave it alone and have yearly followup at your Doctor. Again this type of swelling is not dangerous or cancerous
Hope this will help you.
Please feel free to ask followup questioins.