TGCT (Tenosynovial Giant Cell Tumor)

Tenosynovial Giant Cell Tumor (TGCT) is a rare, benign tumor that occurs in the joint, tendon sheath, or bursae. In 2013, the World Health Organization reclassified related conditions—Giant Cell Tumor of the Tendon Sheath (GCT-TS), nodular tenosynovitis, pigmented villonodular synovitis (PVNS), and diffuse-type giant cell tumor—under the single entity of TGCT, with two distinct subtypes.

Characteristics and Behavior

TGCT is non-life-threatening but locally aggressive. It often causes significant discomfort and can interfere with joint function. The tumor can be classified as either localized or diffuse, with the latter being more likely to recur after treatment. These tumors are benign but can exhibit characteristics similar to soft tissue cancers, known as sarcomas.

Symptoms

Symptoms of TGCT include joint pain, swelling, stiffness, and reduced range of motion. It is essential to consult a healthcare provider if you experience these symptoms.

Causes

The exact cause of TGCT is unknown, but it involves abnormal cell growth in the synovium, a thin layer of tissue lining the joints and tendon sheaths.

Risk Factors

TGCT can affect people of all ages but is most commonly diagnosed in individuals aged 25-50. There are no specific known risk factors for developing TGCT.

Treatment Options

Treatment for TGCT should be individualized based on the tumor type, location, symptoms, extent of joint involvement, and the patient’s functional needs. Surgery remains the main treatment approach, particularly for localized TGCT, with the goal of removing the tumor and preserving joint function. However, recurrence can occur, especially in diffuse TGCT, and repeated surgery may not always be feasible or desirable.

Other treatment strategies may include observation for minimally symptomatic disease, physical therapy to improve function and reduce stiffness, and radiation therapy in selected cases. Targeted drug therapies are an evolving area of research in TGCT, particularly treatments directed at the CSF1/CSF1R pathway. While newer targeted options are being actively studied internationally and may become important in the future, their availability in Canada may be limited or still pending regulatory approval and reimbursement.

The optimal treatment plan should be discussed with a specialist team and tailored to the patient’s symptoms, disease extent, recurrence risk, potential treatment side effects, and personal goals.