A 39-year-old man presented with an asymptomatic, ruberry firm lobulated nodule involved the middle finger. Clinically, it fits the diagnosis of giant-cell tumor of the tendon sheath (giant-cell synovioma or localized nodular tenosynovitis). The cause is unknown and usually presents in mid-life. The nodule is usually asymptomatic, but in occasional cases there may be pain, numbness or stiffness of the digit. There is a strong association with osteoarthritis. The lesions do not regress, and they can persist for many years.