Our aim was to assess the specific ultrasonic characteristics of pleomorphic adenoma and Warthin's tumor in major salivary glands.
Methods: We retrospectively reviewed and analyzed the ultrasonographic (US) features of 19 pleomorphic adenomas in 16 patients and 29 Warthin's tumors in 20 patients. The features included tumor size, echotexture, boundary, and shape on gray-scale US imaging and grading and distribution of tumor vascularity on color Doppler ultrasound (CDU).
Results: All lesions were hypoechoic, and only 22.9% had a homogeneous echotexture. Most of the tumors (87.5%) were >or=10 mm, and 93.8% were well defined. On CDU, 91.7% had intermediate (+ and ++) grades of vascularity. Only two of 29 Warthin's tumors had the highest grade of vascularity (+++). Predominantly central blood flow was present in 58.6% of Warthin's tumors and 42.1% of pleomorphic adenomas. Lobulated margin (shape) was noted in 84.2% of pleomorphic adenomas and 51.7% of Warthin's tumors (P<.05). Anechoic cystic components were present in 13 (44.8%) of 29 Warthin's tumors and in only one pleomorphic adenoma (1/19, 5.3%) (P<.01).
Conclusion: Most pleomorphic adenomas were lobulated. Internal anechoic cystic components were absent from pleomorphic adenomas but present in some Warthin's tumors. The grading and distribution of blood flow signals on CDU provided only limited additional diagnostic information for distinguishing pleomorphic adenomas from Warthin's tumors. Gray-scale ultrasonography is a useful method for evaluating and distinguishing pleomorphic adenomas from Warthin's tumors.