Only 4.5% of brown tumors involve facial bones; of these, solitary bone involvement is usual. Brown tumors of multiple facial bones are extremely rare. Here, we report the case of a brown tumor of multiple facial bones initially misdiagnosed as an odontogenic cyst.Patient concerns:
A pregnant 26-year-old woman was referred to our hospital with painful swelling of multiple facial bones, anemia, urinary calculi, marasmus, and a history of multiple bone fractures. Laboratory examination revealed an elevated serum calcium level of 3.09 mmol/L (normal range: 2.0–2.8 mmol/L) and a low phosphorus level of 0.62 mmol/L (normal range: 0.81–1.65 mmol/L). The serum alkaline phosphatase concentration was 397 IU/L (normal range: 24–82 IU/L) and parathyroid hormone level was 267 pg/mL (normal range: 14–72 pg/mL). Cone beam computed tomography revealed multiple ossifying fibromas of the maxilla and mandible. Incisional biopsy revealed abundant spindle cells with areas of hemorrhage and haphazardly arranged diffuse multinucleated giant cells.Diagnoses:
The patient was diagnosed with primary hyperparathyroidism (HPT).Interventions:
She was treated by parathyroidectomy.Outcomes:
The multiple osteitis fibrosa cystica gradually resolved as bone re-mineralized. The patient has been followed up for 2 years without evidence of tumor recurrence.Lessons:
As multiple osteolytic lesions of facial bones can be caused by primary HPT, serum calcium and parathyroid hormone assays should be performed routinely when investigating these lesions.