Brain abscess secondary to medication-induced osteonecrosis of the jaw

A 75-year-old woman was referred to our department because of delayed post-extraction healing of the tooth socket. Medical history included zoledronic acid administration from 2007 to 2013 for bone metastases of breast cancer. Therefore, she was diagnosed with medication-related osteonecrosis of the jaw (MRONJ). MRONJ is an adverse event often clinically encountered among patients undergoing chemotherapy. Initial treatment included local irrigation and antibiotic therapy, but as the symptoms continued to gradually worsen, curettage of the sequestrum was performed three times. Sequestration finally occurred in most of the maxilla. However, inflammation had spread from the masticator space through the foramen ovale, resulting in a brain abscess (left inferotemporal cortex). Surgical drainage was performed by the neurosurgeon, but the patient's symptoms failed to improve. She died on postoperative day 21. Brain abscess secondary to MRONJ is a rare condition and this is the first reported case resulting in patient death.