Clinical History
37-year-old man with right ankle pain found to have a mass within the ankle joint on MR examination.
Diagnosis: Tenosynovial Giant Cell Tumor
Tenosynovial giant cell tumor (historically known as pigmented villonodular synovitis) is a usually benign proliferative synovial neoplasm that can have localized or diffuse involvement of the joint, but may also affect bursae or tendon sheaths.
Sonographic appearance is of nonspecific synovial thickening which can have varying configuration.
However, ultrasound guidance is particularly useful when the lesion is amenable to core biopsy, facilitating histologic analysis which provides definitive diagnosis.