Osteonecrosis of jaw secondary to stem cell transplant

Abstract

<h3>Background</h3> Osteonecrosis of the jaw (ONJ) is necrosis of mandibular or maxillary bone, which may lead to bone exposure, regardless of the etiology. It is thought to be attributed to insufficient blood supply and altered bone turnover, resulting in a disrupted repair process and eventually leading to the collapse of bone in the setting of microfractures. We report what is, to the best of our knowledge, the first case of ONJ secondary to stem cell transplant (SCT). <h3>Case Summary</h3> A 69-year-old woman with a medical history significant for hypertension, osteopenia, and myelodysplastic syndrome, status post-haploidentical SCT in March 2018, presented for evaluation of asymptomatic exposed bone of the maxilla and mandible. She had no history of radiotherapy to her head and neck; however, she had undergone total body irradiation of 2 Gy in February 2018 as part of her conditioning regimen. She had no history of exposure to a bisphosphonate, receptor activator of nuclear factor-κB ligand inhibitor, antiangiogenic medicine, or corticosteroids. Her current medications included amlodipine, metoprolol, omeprazole, tacrolimus, sulfamethoxazole-trimethoprim, acyclovir, cholecalciferol, and folic acid. She did not have gingivitis or active periodontal disease. The patient had developed exposed necrotic bone sequestra in several areas of the buccal aspect of her maxillary and mandibular gingiva 2 months after her transplant in May 2018. The pathology report indicated fragments of necrotic bone with acute inflammation and bacterial overgrowth consistent with osteonecrosis. <h3>Conclusions</h3> There is evidence that the microenvironment of the marrow stromal system is severely and irreversibly damaged after SCT. The deficit in the quantity and quality of osteoblastic progenitors may compromise the ability to regenerate a normal osteogenic cell population, leading to an abnormality in bone remodeling/turnover. Although osteonecrosis of the appendicular skeleton is a common complication after SCT, there have been no reports of association with ONJ. Particularly interesting is the pattern of ONJ presentation in all the 4 quadrants in this patient.