Abstract
Malignant tumors of the head and neck involve the mandible by direct invasion from soft tissues into the cortical bone and the bone marrow accompanying bone destruction and by intramedullary invasion along the mandibular canal. In clinical pathology, the pattern of bone infiltration of malignant tumors is classified into the osteolytic type, osteoplastic type, and intertrabecular type. For determination of the area of mandibulectomy, imaging studies of the tumor by high-resolution MRI are needed. But this determination is difficult depending on the presence or absence of intramedullary metastasis or dissemination, or when the tumor has become fibrous due to radiation therapy in the past. We studied the pattern of cortical and medullary invasion histopathologically in 18 patients who underwent mandibulectomy with malignant tumors of the head and neck region in whom preoperative imaging diagnoses could be compared with pathological findings. All 16 patients with squamous cell carcinoma showed osteolytic type which was continuous in the mandibular marrow without intramedullary metastasis. Since squamous cell carcinoma invading into the mandible shows continuous and direct bone invasion, the clinical management of mandibulectomy may be determined with high-resolution MRI.
