[Tenosyovial giant cell tumor (TGCT): From the physiopathology to the emergence of new targeted therapies].

Tenosynovial giant cell tumors (TGCT) are rare synovial proliferations classified as localized or diffuse forms, driven predominantly by Colony-Stimulating factor 1 (CSF1/CSF1Receptor) signaling. A minority of neoplastic cells overexpress CSF1, leading to massive recruitment of CSF1Receptor-positive macrophages. MRI often allows diagnosis in typical cases, while biopsy remains necessary in atypical or extra-articular forms. This disease, although not lethal, has major functional and psychosocial consequences. Surgery is the main treatment ; CSF1R inhibitors are emerging for unresectable or recurrent disease and are available since March 2026 requiring a rethink of the patient care journey.