Classifying Localized vs Diffuse TGCT and Deciding Who Needs Surgery First

The faculty address how tenosynovial giant cell tumor (TGCT) is diagnosed and classified and whether every patient needs surgery first. Two questions guide evaluation: how extensive the disease is, usually framed as nodular vs diffuse, and what effect the tumor has on the patient’s quality of life. Localized disease, seen in the hand and foot and also in the knee, is described as a discrete nodule amenable to excision with very high cure rates. For diffuse disease, magnetic resonance imaging (MRI) defines the relationship to tendon, cartilage, and neurovascular structures, and biopsy is described as necessary before systemic treatment. Beyond technical resectability, the faculty ask whether surgery will give a durable response. They cite a multicenter active surveillance study in which about two-thirds of patients did not progress over 2 years.