Tenosynovial giant cell tumor in an unusual localization

Tenosynovial giant cell tumors are benign tumors that are often localized on the palmar sites of the hand. The involvement of large joints such as the knee and ankle are rare. We present an 18-year-old male patient referred to the orthopedics clinic with a mass on his right ankle. No differential diagnosis could be made radiologically. The marginally excised lesion was histopathologically diagnosed as a tenosynovial giant cell tumor. There was no local recurrence during a follow-up of 12 months.