THU446 A Case Of Isolated Osteonecrosis Of Torus Palatinus In A Patient On Alendronate

Disclosure: A.A. Noor: None. A. Zia: None. B. Hoard: None. K. Romo: None. S. Bhamre: None. M. Gabriel: None. S. Shu: None. R. Ozolins: None. T. Pulisetty: None. G.I. Uwaifo: None. Introduction: Osteonecrosis of the jaw (OJN) is a rare complication of bisphosphonate and RANKL inhibitor use. Most cases have been described in cancer or immunocompromised patients using high dose parenteral therapy, but have even more rarely been described with oral bisphosphonate (OBP) use. The estimated risk is 1 in 10,000 to 1 in 100,000 patient-years in patients taking OBP for osteoporosis. We describe a case isolated osteonecrosis of torus palatinus (OTP) in a patient with long-term use of OBP (alendronate) for postmenopausal osteoporosis. Case Report: 75-year-old female with a history of torus palatinus (TP), osteoporosis, fibromyalgia, echondromas of humerus, degenerative disc disease, and spinal stenosis initially presented at a primary care clinic with three weeks of inflamed, painful, red, and swollen oral ulcer; associated with exudative tonsillitis. She finished an antimicrobial course which improved tonsillitis, but the oral ulcer persisted. She was on alendronate 70 mg weekly for ∼ three years prior to symptom onset. Examination showed a nearly 1 cm shallow ulcer on the left aspect of her large TP with associated erythema and tenderness to palpation. The rest of the oral cavity was normal. She was given triamcinolone paste for two weeks. Follow-up 1 month later showed progression of ulcer down to bone underlying the TP. The mucosa of the TP was erythematous, thickened, and tender. Given the lack of resolution after antimicrobials and topical steroids, a biopsy was done which showed squamous mucosa with reactive changes, hyperkeratosis, and chronic inflammation, but negative for dysplasia or malignancy. Maxillofacial CT showed, “a lobulated bony mass in the roof of the mouth consistent with TP with left-central heterogeneous density and cortical bone thinning without soft tissue mass or extension. Due to suspicion for osteomyelitis and possible underlying malignancy, lesion excision, and debridement was done. Alendronate was stopped at this point. Excisional biopsy showed necrotic bone consistent with OTP with associated acute and chronic osteomyelitis. She was treated with four weeks of metronidazole and two weeks of fluconazole. The postoperative course was uneventful, with appropriate healing. Conclusion: While OJN is uncommon in setting of OBP use, among patients with TP and other bone overgrowth states high index of suspicion is needed for bony lesions developing in such patients. The possibility of OTP development should be considered with appropriate oral complaints among OBP users with TP. Further retrospective analyses to ascertain how prevalent this uncommon condition is would provide much needed clinical information. Presentation: Thursday, June 15, 2023