Central skull base invasion of maxillofacial tumors: computed tomography appearance

The aim of this study was to demonstrate computed tomography (CT) features of maxillofacial tumors invading the central skull base and to offer information in aiding diagnosis.

Fifty-eight maxillofacial tumors with central skull base invasion shown on axial and coronal CT images were divided into benign (13 cases) and malignant (45 cases) groups, based on their pathologic outcomes as proven by biopsy and surgery.

Four manifestations of the skull base abnormality were observed on CT images: (1) resorption of central skull base (53 cases, 11 benign and 42 malignant tumors); (2) enlargement of the foramen and canal in the central skull base (20 cases, 4 benign and 16 malignant tumors); (3) thinning of the central skull base (11 cases, 8 benign and 3 malignant tumors); and (4) displacement of the central skull base (5 cases, all benign tumors). The following structures of the central skull base were involved: the roof of the pterygoid process of the sphenoid bone (49 cases), the sphenoid greater wing (37 cases), the sphenoid body and sinus (33 cases), the petrous apex (12 cases), the clivus (4 cases), and the articular surface of the temporal squama (3 cases). Of 58 patients, 30 (7 benign and 23 malignant) had tumors with central skull base erosion that infiltrated into the cranial cavity.

Benign maxillofacial tumors with center skull base erosion tended to lead to the displacement and thinning of the base of the middle skull fossa in contrast with tumors with malignant maxillofacial tumors. It is believed that these CT manifestations might be valuable in making a differential diagnosis.