Clinical study of parotid gland tumors

Abstract

We did a clinicopathologically survey on 27 patients treated for parotid tumors. Echography and sialography yielded a diagnostic accuracy of 82 to 89 percent. These methods were more useful in the preoperative diagnoses of malignancy than RI-scintigraphy (^99mTc, ⁶⁷Ga). Echography should be the first choice for imaging tumors because it is simple. Computed tomography (sialo-CT) is most useful for locating the tumor.
Under the histological classification of the World Health Organization (1991), 21 of the 27 cases were benign, and 6 were malignant. The most prevalent tumor among the benign lesions was 17 cases of pleomorphic adenoma.
Four of the pleomorphic adenoma cases represented a histologically distinct group of tumors, different from benign and malignant lesions. We referred to these lesions as intermediate, semi-malignant tumors. Cellar atypism and capsular invasion in the histological findings were deemed important criteria for diagnosis of this intermediate type. Pleomorphic adenoma of the intermediate type has the potential for malignant change, and should therefore be followed closely. Shika Igaku (J Osaka Odontol Soc) 1996 Jun; 59(2): 146-158.