Pathology of Osteomyelitis

Abstract

According to the Zurich classification on osteomyelitis of the jaws, pathology is considered a secondary classification criterion. Pathology serves to confirm the diagnosis of osteomyelitis if clinical judgment and diagnostic imaging studies are not conclusive. Histology of jaw osteomyelitis should always be complemented and interpreted in conjunction with clinical and radiological findings and should not be used independently. Importantly, it is an essential tool to exclude differential diagnoses such as malignant tumors, fibrous dysplasia, and other tumor-like lesions. Harvesting biopsy specimens from a representative area, correct tissue submission and tissue preparation are prerequisites to obtain a conclusive histology. Histopathology of acute and secondary chronic osteomyelitis encompasses the full scope of inflammatory infiltrates ranging from mainly inflammatory exudate composed of fibrin, polymorphonuclear leucocytes and macrophages in the acute stage, to a predominant plasma cell infiltration accompanied by a variable extent of marrow fibrosis. A clear distinction from primary chronic osteomyelitis to secondary chronic osteomyelitis solely based on histopathology is not always possible; however, in context with clinical presentation and imaging studies, histology contributes to specify the diagnosis of chronic osteomyelitis. Furthermore, “specific” osteomyelitis is defined by a histological picture with granulomatous inflammatory response to specific pathogens, such as Mycobacteria, and necessitates adequate therapy.