Synovial hemangioma of Hoffa fat pad demonstrated by RBC SPECT/CT.

Synovial hemangioma of Hoffa fat pad is an extremely rare disease, which occurs in the knee joints. Because synovial hemangioma often shows nonspecific symptoms, such as pain, swelling, limping, or limitation of motion, diagnosis could be delayed in many cases. We present a 7-year-old boy referred to our department for Tc red blood cell (RBC) scan for the confirmation of hemangioma suggested by the MRI. RBC scan demonstrated intense radioactivity accumulation in Hoffa pad of right knee joint, and subsequent excision biopsy revealed the mass as venous hemangioma.