Accuracy in the diagnosis of parotid tumours.

Parotid lesions are often not easily classified. Important information is gathered by conventional and instrumental investigation. But these data are often insufficient to make a correct diagnosis. The authors have compared these techniques. In particular, they have evaluated their accuracy in identification of site and histology. 60 patients with parotid tumours underwent the same instrumental diagnostic techniques (echography, sialography, computed tomography and fine needle aspiration biopsy). In regard to the identification of the site, the highest percentage was achieved by computed tomography (98\%). Echotomography has shown an accuracy of 83\%, and sialography 87\%. Fine needle aspiration biopsy has allowed the definition of the histiotype in 98\% of cases. Computed tomography, echotomography and sialography have not allowed the definition of histiotype in malignant tumours, but in the case of benign tumours computed tomography has permitted a diagnosis in 29 cases (57\% of benign tumours). Echotomography and sialography in 25 (49\%) and 26 cases (51\%), respectively.