Radiologic features of benign pleomorphic adenoma of the hard palate.

The clinical and radiographic features of two cases of pleomorphic adenoma are discussed. With the use of hypocycloidal tomography, definitive radiographic signs of benignity are demonstrated. They include (1) a radiolucent defect with well-defined cortical margins; (2) beveled margins which describe an intraoral origin of the neoplasm; (3) confinement of the neoplasm within the actual osseous defect, or within the projected circumferential diameter of the defect, if complete erosion has occurred; and (4) lack of periosteal reaction or osseous involvement of the hard palate adjacent to the radiolucent defect.