Barzilai University Medical Center

81 Research Day 2020 Barzilai University Medical Center 58 CENTRAL INFLAMMATORY MYOFIBROBLASTIC TUMOR OF THE JAWBONES: EXCEPTIONAL LOCATION OF AN UNCOMMON ENTITY Alex Neronov 1 , Oded Nahlieli 1 , Amram Zagury 1 , David Ben-Dor 2 , Alejandro Livoff 2 , Irit Allon 2 1 Department of Oral and Maxillofacial Surgery, Barzilai University Medical Center, Ashkelon, Israel 2 Department of Pathology, Barzilai University Medical Center, Ashkelon, Israel Faculty of Health Studies, Ben Gurion University of the Negev, Beer Sheva, Israel Background Inflammatory myofibroblastic tumors (IMTs) are uncommon neoplasms of intermediate biologic behavior that typically present in the lungs of children and young adults but may occur elsewhere in the body. The head and neck are an unusual site of involvement and in the jaws, these are even less common. Hypothesis IMT has a wide spectrum of presentations. Paladin can be used as a marker of myofibroblastic cells. Objectives The purpose of this study is to present a central IMT arising within the bone of a seven-year-old female and to analyze the available literature of intrabony/central IMTs of the jaws. Results 25 cases including the present one were included. The mean age of the patients was 34.8+19.6 years. The mandible was affected in most cases. All cases were osteolytic, all but the present one were unilocular, and more than 50% were well defined. Bony expansion was evident in 42.8% and root resorption in 53.8% of the cases. The lesions were composed of spindle fibroblastic and myofibroblastic cells with a variable inflammatory infiltrate, most commonly lymphocytes (85%) and plasma cells (75%), but other inflammatory cells such as neutrophils, eosinophils and mast cells were also present. Immunohistochemically smooth muscle actin was positive in 100% and ALK1 was positive in 6 of 14 cases (42.8%). 2 cases were h-Caldesmon positive. The present case stained diffusely with an antibody against Paladin, implicated in mesenchymal transition process of metastatic breast carcinoma. Treatment options consisted mostly of surgery, but pharmacological therapy with glucocorticoids and combinations of these were also documented. Conclusions Central IMT of the jawbone is a rare tumor that could have an alarming clinical presentation. The differential diagnosis of spindle cell lesions accompanied by inflammatory infiltrate in children is diverse; Paladin antibody could be used to emphasize the myofibroblastic nature of the lesion.