THU453 Chronic Headaches As A Presentation For Monostotic Craniofacial Fibrous Dysplasia: A Case Study

Disclosure: B. Dyer: None. R.K. Bhattacharya: None. Background: Monostotic craniofacial fibrous dysplasia (CFFD) is often asymptomatic and is found incidentally on imaging. Previous reports described cases in which CFFD diagnosis was preceded by chronic headaches, but there remains a lack of clinical association between these diagnoses. Clinical Case: Patient is a 22-year-old female with a long history of chronic headaches who presented to the emergency department two days after a motor vehicle accident with complaints of headache, blurred vision, nausea, and dizziness. CT revealed an incidental sclerotic mass in the left frontal region measuring 7.9x7.3x3.7cm extending inferiorly into the left ethmoid sinus. At her primary care follow-up, she reported a pounding, left-sided headache in addition to balance issues, dizziness, nausea, and blurry vision. Workup was significant for vitamin D level of 11.2ng/mL (n = 30-100ng/mL), alkaline phosphate of 106U/L (n = 35-104U/L), and calcium of 9.1mg/dL (n = 8.6-10.3mg/dL). MRI was significant for a heterogeneous, hypointense expansile calvarial lesion within the left frontal and left sphenoid bones. The patient was diagnosed with CFFD based on radiologic findings. The patient was advised against surgical intervention due to her disease’s large, invasive nature. The patient was seen by neurology for recurrent headaches and was subsequently started on topiramate with partial symptom relief. Endocrinologist management included confirmation of monostotic CFFD by bone scan. Biopsy was deferred due to the low likelihood of malignant transformation, and bisphosphonate treatment was initiated. She was subsequently started on 5000 IU per day of vitamin D to normalize the vitamin D level before the initiation of bisphosphonate treatment for her pain. She received 5mg intravenous infusion of zoledronic treatment. At follow-up, the patient states she had significant improvement in all symptoms. Conclusion: Pain from FD can be debilitating and often increases in severity as the patient ages, though pain is not strongly correlated to presentation or disease burden. The mechanism by which CFFD produces pain is not fully elucidated. The unique innervation of bone and the creation of new sensory nerve fibers during inflammatory states may contribute. Additionally, excess IL-6 during inflammatory states may also play a role in pain production due to lesion expansion from osteoclast activation, cystic formation within the lesion, and hormonal reactivity of the lesion. Bisphosphonates are believed to inhibit IL-6 production, reducing osteoclastic activity and leading to symptomatic pain relief. In the case presented, the patient’s chronic headaches improved significantly following combination therapy with migraine abortive medication and bisphosphonate therapy. Early recognition and multidisciplinary treatment are key in the long-term management of CFFD pain. Presentation: Thursday, June 15, 2023