Chronic, reactive conditions of the oral cavity simulating mucosal carcinomas: CT and MR imaging findings with pathologic correlation in five patients.

To investigate the radiologic and pathologic findings of chronic, inflammatory, reactive conditions of the oral cavity, which clinically and radiologically simulate mucosal malignancy, computed tomography (CT; n=4) and magnetic resonance (MR; n=2) images, as well as surgical specimens, obtained from five patients with surgically proved, chronic inflammatory mass of the oral cavity were retrospectively reviewed. All patients had a palpable mass or ulcerative lesion in the oral cavity. On CT and MR images, all three lesions in the oral tongue and one lesion in the retromolar trigone were seen as a superficial, ill-marginated, well-enhancing ellipsoid or focal soft tissue mass. Pathologic examinations revealed various depths and degrees of acute and chronic inflammation, granulation tissue, and fibrosis in the subepithelial stroma, accompanied by pseudoepitheliomatous hyperplasia in these four patients. In the remaining one patient with lesion in the hard palate, CT showed a relatively well-marginated, well-enhancing soft tissue mass, which histologically proved to be irritation fibroma. Neither clinical nor radiologic manifestations could afford clues to make the correct diagnosis, which therefore should rely on histology. Some forms of chronic, inflammatory, reactive conditions of the oral cavity are nearly indistinguishable from the malignant tumors both clinically and radiologically. Knowledge of this entity may obviate the unnecessary and somewhat disfiguring operation.