CT Manifestations of Parotid Pleomorphic Adenoma

Objective To study CT characteristics of parotid pleomorphic adenoma.Materials and Methods CT findings of 18 cases with pathologically proved parotid pleomorphic adenoma were reviewed. The lesions included benign pleomorphic adenoma (n=12), benign recurrent pleomorphic adenoma (n=4) and malignant pleomorphic adenoma (n=3).Results Of 12 benign pleomorphic adenomas, 8 were round or ellipse in shape, the other 4 were multi nodular and lobulated. All the 12 lesions were well defined and inhomogeneous in density with multiple low attenuation areas within the tumor. All the 4 recurrent tumors showed multiple lesions, presenting as multi nodules (n=2) or a multi ring like mass (n=2). The three malignant pleomorphic adenomas were inhomogeneous in density with ill defined margin and large central necrotic area.Conclusion Benign pleomorphic adenoma displays as a mass with well defined margin and central low attenuation area. Malignant pleomorphic adenoma should be considered when the lesion is ill defined with large central necrotic area, especially in the patients with a long course of parotid mass which quickly enlarges recently.