Evaluation the value of CT scanning in diagnosing parotid massas (a report of 89 cases)

Objective: To evaluate the value of CT findings in diagnosing and differential diagnosis of parotid masses. Methods: The CT findings of 89 parotid masses proved by operation and pathology were retrospectively analyzed. Results: Of all the 89 parotid masses, there were 44 benign tumors, 7 retention cysts, 8 inflammatory lesions and 30 malignant lesions. All the cases were accurately localized. Benign tumors and retention cysts showed regular and well-defined margins (49/51). In the other hand, irregular and ill-defined margins (22/30) with surrounding tissues infiltration(11/30) were found in malignant masses (P<0.01). The parotid tissues around the lesions showed ground-grass appearance in 4 cases of tuber-culosis and 2 inflammatory lesions. 4 cases of adenolymphomas were multifocal. The CT diagnostic accuracy was 82% in differentiating benign and malignant lesion (73/89). Conclusions: CT can localize parotid masses excellently and is useful in the differentiation of the benign and malignant lesions. But it is unable to tell the pathologic type of the lesions. Ground-grass appearance is the characteristic feature of tuberculous and inflammatory nodules. (authors)