Medical Case Details:
A heart transplant recipient, who is a 65-year-old female, presented to the transplant clinic. Her complaint is right index finger swelling that evolved 6 months after the transplant. Her immunosuppressive medications were Tacrolimus, CellCept, and Prednisone. The swelling was getting worse in the last month. There is no associated pain, tenderness or fever. There is no previous history of trauma.
On physical examination, 4 cm mass along the right middle metacarpophalangeal joint. There is no erythema, warmth, or tenderness. CT was performed and showed a multilobulated mass. What is the next step? What do you think that patient might have?