There is no single universal treatment scheme for FD. The chosen approach depends on lesion location, symptoms, patient age, and disease extent. Below we describe the available options - from observation to the latest therapies - in line with current international guidelines (FD/MAS Consortium 2019, published in Orphanet Journal of Rare Diseases).
Open FD/MAS Consortium 2019 consensus →
Note: Educational content, not a substitute for a medical consultation. Materials and guidelines (such as the FD/MAS Consortium 2019 consensus) are intended for a conversation with the treating physician, not for self-application. Every FD/MAS case requires individual evaluation - consult a clinician experienced with FD/MAS.
In children with FD who feel no pain and have no functional impairment (vision, hearing, breathing), the standard is observation until skeletal maturity is reached. FD activity typically decreases after growth completes. Leading global centers - Leiden UMC, Sapienza, UCSF - unequivocally recommend deferring surgical intervention without clear clinical indications.
Observation does not mean inaction. The patient should be monitored periodically: imaging (CT/MRI), clinical follow-ups, and - in cases of polyostotic FD or suspected MAS - regular hormonal tests.
Used primarily for bone pain associated with FD. Bisphosphonates (e.g. pamidronate, zoledronate) reduce bone resorption and may ease pain. Administered intravenously in cycles.
Bisphosphonates do not reverse FD lesions - they do not "cure" the disease. Their role is symptomatic: pain reduction and potential progression slowdown. They require monitoring of calcium and vitamin D levels. The decision to start them is made by an endocrinologist or treating physician after assessing symptom severity.
A monoclonal antibody blocking RANKL - the key factor activating osteoclasts (bone-resorbing cells). Used in cases of FD with rapid lesion growth or severe pain when bisphosphonates are insufficient. Administered subcutaneously, usually every 6 months.
Denosumab requires careful use - after discontinuation a rebound effect may occur, accelerating bone resorption. Treatment should be conducted by an experienced endocrinologist, ideally at a referral center.
A monoclonal antibody against FGF23 - a factor over-produced by FD cells that causes phosphate loss through the kidneys. In FD patients with hypophosphatemia (low blood phosphate), burosumab normalizes phosphate metabolism, which may improve bone mineralization.
Burosumab is registered in the USA under the trade name Crysvita (originally for X-linked hypophosphatemia). Its use in FD is novel and requires specialist qualification. Availability in Europe may be limited.
Surgery in FD is considered after skeletal maturity, when a lesion causes significant functional impairment (nerve compression, breathing difficulty) or major aesthetic deformity. The surgical goal is usually contouring (reducing lesion mass), not radical excision.
In children, surgery is not the standard of care. FD can regrow after incomplete excision, and surgery during the growth period carries risks of recurrence and complications. Any surgical decision should be consulted with a center experienced in FD.
Regardless of the chosen therapeutic approach, every FD patient requires regular monitoring:
The therapeutic options above are described based on current international clinical guidelines for FD/MAS and publications from leading referral centers:
Open FD/MAS Consortium 2019 consensus →
Knowledge about FD/MAS continues to evolve. We strive to update this information as new clinical data and guideline revisions appear. The 2019 consensus is planned for revision every 5 years - we follow new versions and note significant changes.