Review of TSGCT Subtypes: Diffuse Vs Localized Disease

Transcript:

Shreyaskumar R. Patel, MD: Let me see if I can get Dr Tae Won Kim involved. He is 1 of our other orthopedic oncology colleagues on the panel. Dr Kim, do you have anything to add in terms of the symptoms or the presentation? Maybe you can elaborate on the distribution of the two major subtypes that we talk about: the diffuse variant or the localized variant, if you will, that frequently gets called “giant cell tumor of tendon sheath.”

Tae Won B. Kim, MD: Thanks for having us. It’s great to participate on the panel. Dr Abraham gave a great overview of this entity that we’re understanding more about. There are two subtypes of this entity. There is one called the diffuse type, which we generally call PVNS or pigmented villonodular synovitis; and then there are more localized or nodular types, which are focally involved.

The nodular types are more consistently found in the extremities such as the hands and feet around tendon sheaths and bursa, and they’re usually localized, solitary nodules. They can have a little bit of a diffuse nature when you look at them with radiology, but overall, they tend to be fairly localized in their distribution. The more symptomatic cases that we tend to have more difficulty dealing with are the diffuse type or cases that occur on a larger joint such as the knee, which is most common location. As Dr Abraham mentioned, the symptomology is variable, although the diffuse type on the larger joints tends to be much more symptomatic.

Just recently, I had a patient come in who has what appears to be giant cell tumor of tendon sheath around the first ray of the foot. It is arising from the joint with significant joint destruction and a huge soft tissue component coming out into the periphery. Even though that will be considered localized given its location, its behavior seems to be more of a diffuse type. Even though there is the categorization of diffuse and localized types, I think you must take into context how it is behaving within that area.

Shreyaskumar R. Patel, MD: One area of debate all along has been, is there transition from one type to the other? If yes, what’s the proportion of transition from one variant to another? Is it common that the localized variant at presentation, after multiple attempts at therapy from a surgical standpoint, eventually turns into the diffuse variant? What’s the timeframe? What’s the course of the disease? If you can give our audience your experience and your input, I think that may be helpful, especially in terms of trying to catch patients in a multidisciplinary setting at the right point in time for appropriate multidisciplinary treatment.

Tae Won B. Kim, MD: That’s a great question. The flow in which patients do come to our office tends to be what Dr Abraham mentioned. Patients come from a general orthopedist who’s seeing them for generalized knee pain or ankle pain or hip pain. They are receiving appropriate conservative measures with benefit and then being evaluated with further advanced imaging studies and finding out that they have this mass or mass-like entity in their joint.

In terms of my experience with seeing localized disease become diffuse disease, the only times I’ve really seen it happen is when there have been multiple local recurrences after the initial resection had occurred. There’s debate as to whether arthroscopic removal of some of these tumors in the larger joints of a nodular or more localized entity can potentially cause joint seeding, and that can potentially cause the development of larger local recurrences down the line. Debate is always ongoing as to what’s the best surgical management of the entities. When I’ve seen localized disease become more diffuse disease is when patients experience local recurrences within the first 1 to 2years after the local resection has occurred. That’s generally my experience with that.

Shreyaskumar R. Patel, MD: Very good.

Transcript Edited for ClaritySupported by an unrestricted educational grant from Daiichi Sankyo.​​​​​​​