Descending necrotizing mediastinitis after sequestrectomy in a patient with bisphosphonate-induced osteonecrosis of the jaw: A case report.

An 83-year-old woman underwent mastectomy for breast cancer of the right breast in 2008. In addition to hormone therapy and irradiation, zoledronate was started for bone metastasis 6 months postoperatively. Five years after the operation, the patient developed osteonecrosis of the jaw, and underwent sequestrectomy because of uncontrollable pain in the mandible. The patient visited our hospital for a 1-week history of fever and right facial swelling with pain, and was diagnosed with right mandibular cellulitis. Despite antibiotic therapy, the patient fell into shock. Follow-up computed tomography showed gas formation extending down to the posterior mediastinum, which was compatible with descending necrotizing mediastinitis (DNM). The patient succumbed to septicemia on the third hospital day. The mortality rate of DNM greatly increases in patients with advanced cancer because clinicians cannot perform radical treatment due to the impaired general condition and limited life expectancy. DNM advances by the hour; therefore, repeated computed tomography is essential when antibiotic therapy does not improve the patient's condition. Attention must be paid to detect signs of DNM in such patients. To the best of our knowledge, this is the first report in English regarding DNM caused by bisphosphonate-induced osteonecrosis of the jaw.