BISPHOSPHONATE-INDUCED OSTEONETROCROSIS OF THE JAW IN CANCER PATIENTS: A HISTOPATHOLOGICAL STUDY

Background. Osteonecrosis of the jaw associated with the use of bisphosphonates, such as zoledronic acid, occurs in patients with malignant tumors with metastatic bone lesions and is a severe complication that significantly reduces the quality of life and survival of patients. Aim: to investigate pathomorphological features of bisphosphonate-induced osteonecrosis of the jaw in oncologic patients with metastatic cancer in the bones who used zoledronic acid. Materials and methods. We performed a pathomorphological study of surgical specimens after sequestrectomy of the jaw with bisphosphonate osteonecrosis in patients with metastatic cancer. Patients were treated with intravenous zoledronic acid; in one case the main diagnosis was prostate cancer, in the other case renal cancer, and the patients did not have oncological disease of the jaws and patients had not been treated with radiotherapy to this area in the past. Jaw tissue samples were fixed in 10% neutral buffered formalin solution, decalcified, dehydrated in alcohols of increasing concentration, and embedded in paraffin according to the standard method. Histological sections with a thickness of 5±1 μm were made from paraffin blocks with tissue samples on a Leica RM2235 rotary microtome, placed on glass slides with an adhesive coating. For histological analysis, the preparations were stained with hematoxylin-eosin. Histological evaluation of the surgical material was performed using a Leica DM750 universal light optical microscope (Leica Microsystems GmbH). Results. Bisphosphonate-induced necrosis of the jaw was diagnosed in the mandibles and at later stages of development, and the trigger factor was tooth extraction. Pathohistological examination of fragments of the jaw after surgical treatment by sequestrectomy revealed dilated interosseous lacunae, osteons in a state of necrobiosis-necrosis, absence of osteoblasts and osteoclasts, presence of structureless detritus, including in dilated lacunae with hemorrhages. Morphological signs were the absence of inflammatory infiltrate, bacterial colonies and vascular reaction. Conclusion. Bisphosphonate-induced necrosis of the jaw occurs in patients with malignant tumors with metastasis in the bones and with used treated zoledronic acid, which is a prognostically unfavorable sign of the course of the disease. The risk of osteonecrosis, as well as its complications, should be controlled by careful monitoring of patients receiving bisphosphonate treatment in dental clinics.