Tenosynovial giant cell tumor (TGCT): Mechanisms and advances in targeted treatments.

Tenosynovial giant cell tumors (TGCT) are rare, locally aggressive, mesenchymal tumors occurring in the joints and tendon sheaths, which can cause pain, swelling, and have a substantial negative impact on patient quality of life. While surgery is the current standard of care for most cases of TGCT, there are several drawbacks including risk of recurrence and repeated operations. As such, systemic therapies have an important role in the treatment of TGCT. Encompassing both inflammatory and tumorous features, the pathological mechanism of TGCT is relatively complex and the development of effective drugs requires in-depth research and analysis of these mechanisms. Colony stimulating factor 1 (CSF1) is one of several known drivers in TGCT and has been a focus of investigation, among other potential therapeutic targets. Systemic treatments for TGCT have been utilized as part of a multimodal therapeutic strategy for patients who have recurrent or refractory disease, or who are not amenable to surgery. This review summarizes current knowledge of the mechanisms underlying tumorigenesis in TGCT, providing an overview of the key drivers and corresponding therapeutic targets. Further research into the specific mechanisms of TGCT and further development of diagnostics and treatments are warranted.