Imaging characteristics of rare tumor of parotid gland

ZHAO Liu-yan; CHEN Zu-hua

Abstract：Objective To study the imaging characteristics of rare tumor of parotid gland .Methods CT ,MRI imaging findings of 13 cases of rare tumor (4 cases of lymphoepithelial carcinoma ,3 cases of myoepithelioma ,2 cases of lymphoma and metastatic tumors in each 1 case of malignant melanoma and myoepithelial carcinoma in each in the parotid gland) con‐firmed by operation and pathology were retrospectively analysed .Results The lesions were located in the unilateral parot‐id gland ,in the left side (n=8) ,in the right side (n=5) .Lymphoepithelial carcinomas were located in the superficial lobe of parotid gland ,which may violate the deep lobe ,majority of single lesion (3/4) .Casting growth (3/4) along the parotid gland may have certain feature:homogeneous density and signal ,light to moderate enhancement after enhance‐mend .Myoepitheliomas were solitary and located in the superficial lobe of parotid gland ,with oval and sharp edge ,homo‐geneous or inhomogeneous density and signal .Marked enhancement (2/3) may help diagnosis .Lymphoma had certain characteristics ,which manifested multiple round mass (2/2) ,smooth edges and homogeneous density ,moderate enhance‐ment ,frequently accompanied by cervical lymphadenopathy .Malignant melanoma had certain characteristics on MRI:mul‐tiple high signal nodules on T1WI ,low signal on T2WI ,no characteristics on enhanced CT and MRI .Myoepithelial carci‐noma had not different with common malignant tumor of parotid gland .The findings of the metastasis tumor of parotid gland were closely related to primary tumor .Conclusion The part of the above‐mentioned rare tumors of parotid gland have certain imaging characteristics ,which are helpful for differential diagnosis .Final diagnosis still depends on histopa‐thology and immunohistochemistry .