Tenosynovial Giant Cell Tumor

What is a Tenosynovial Giant Cell Tumor?

Tenosynovial Giant Cell Tumor (TGCT) is a tumor of the synovium, or the lining of a joint. All joints have a soft, velvet-like lining tissue that performs a variety of functions, including lubricating the joint. In this condition, there is a signal within the lining tissue that is inappropriately over-expressed. This causes the synovium to become overloaded with normal cells that have been brought into into the synovial tissue by the aberrant signal. This changes the synovium from a soft, velvety material into a gritty, thickened tissue that becomes brittle and can break and bleed inside the joint. This can be severely symptomatic, causing extreme pain and swelling. One analogy for this condition is that a normal joint function can be approximated by rubbing two perfectly flat pieces of ice together: the ice glides on itself very easily and smoothly. TGCT is as if a bag of sand is now introduced between those two pieces of ice: the smooth gliding motion is converted instantly to a grinding, destructive motion. Similarly, TGCT, if left untreated, often leads to compete destruction of the joint, which may require joint replacement at an early age. There is significant limitation of function associated with this condition at every stage, and it can be debilitating. However, except in extremely rare cases, it is generally a benign condition, meaning it cannot spread to other parts of the body. It can still, however, be severely problematic for the patient and often requires aggressive treatment. For this reason, TGCT falls into the category of “Benign but locally aggressive tumors” which very often require treatment.

Where is a Tenosynovial Giant Cell Tumor found?

Tenosynovial Giant Cell Tumor most commonly affects the knee joint although it can be found in other joints as well. It is a rare tumor that only affects about 2-4 people per million in the diffuse form. Typically, the disease affect patients 20-40 years of age, although it can be seen outside this age range as well. There are two forms, the “nodular” form, which is usually a single lump within the synovium, or the “diffuse” form, which usually affects the entire synovium of a given joint, and can even extend outside of the joint. The nodular form, when symptomatic, is generally treated with removal, which often cures the condition. The diffuse form presents much more of a challenge. The synovium can be removed from most joints, called a “total synovectomy”, but the procedure is usually quite extensive. In most joints it is not possible to remove 100% of the synovium, which is partly how the joint still functions after synovectomy. Even after “total” synovectomy, there is a high rate of recurrence. This rate is even higher if the synovectomy is performed through an arthroscopy procedure. Given this, pharmaceutical companies have tried to develop medications that blocks the abnormal signal, and one of these medications so far, called Turalio (pexidartinib)* has proven to be effective. However, this drug has significant potential side effects, and the condition may return once the drug is stopped. For these reasons, the condition is still extremely difficult to treat, and can still have significant impact on the patient.

How is a Tenosynovial Giant Cell Tumor treated?

The decision for surgery or drug treatment, or some combination of both, is best made by a team that is very familiar with this condition and has significant experience with it. Dr. Abraham has a particular interest in Tenosynovial Giant Cell Tumor, and has written several articles and participated in a number of clinical trials and other studies on this condition, and sees patients from across the country for evaluation of possible synovectomy. The knee in particular is difficult to address surgically, and requires a two-stage approach, with an incision in the front of the knee and another incision in the back of the knee. This is a technically challenging procedure which often lasts 6-8 hours or longer but usually results in removal of the vast majority of the diseased synovium from the joint. The rehabilitation is critical as well. However, for patients requiring this procedure, it can be very effective at decreasing pain and other symptoms from this condition.

Dr. John Abraham and  Tenosynovial Giant Cell Tumors

Dr. Abraham has extensive surgical experience with this type of procedure, and uses a particular technique of synovectomy which he feels has improved results and fewer side effects than the traditional technique. He has reported his results at national forums and has lectured extensively on this type of operation. Not every patient will require surgery for TGCT, but for those who do, and experienced team is critical to success. The decision on how to best treat TGCT is made by considering a number of factors, including the level of symptoms, the patient’s age and health condition, the tolerance to medication, the risks of surgery, the condition of the joint, and many others. These are complex decisions that require collaboration between the doctor and patient to come to the best decision. If you are suffering from TGCT, consider a consultation with Dr. Abraham’s team to determine the treatment plan that is best for you. Telehealth visits can be arranged for patients outside of the Philadelphia region.

*Dr. Abraham has served as a consultant for Daiichi-Sankyo who makes Turalio.

Watch a series of videos with Dr. John A. Abraham discussing treatement and approach to Tenosynovial Giant Cell Tumors.

Headshot of Dr. John A. Abraham Orthopaedic Oncologist wearing a medical white coat and smiling.

Potential Symptoms of TGCT

Surgical Improvements in TGCT

Questions With Pexidartinib in TGCT

Clinical Utility of Pexidartinib in TGCT

Surgical Management of TGCT

Future Research in TGCT

Key Considerations in the Management of TGCT