Sonographic diagnosis of parotid gland lesions: correlation with the results of sonographically guided fine-needle aspiration biopsy.

PURPOSE

The aim was to assess the value of ultrasound (US) in differentiating benign from malignant parotid gland lesions.

METHODS

During a 3-year period, US-guided fine-needle aspiration biopsy was performed on 89 parotid lesions with a size > or = 5 mm in 68 patients. In 80 (90%) lesions, specimens were adequate for cytologic analysis. We recorded the seven following US parameters: size, number, echogenicity, echotexture, margins' clarity, distal acoustic enhancement, and regional lymph node enlargement.

RESULTS

Fine-needle aspiration biopsy revealed 18 (22%) malignant tumors, 30 (38%) benign tumors, and 32 (40%) nonneoplastic lesions. The mean size of the malignant tumors was 25 +/- 17 mm versus 27 +/- 17 mm for benign tumors versus 21 +/- 12 mm for nonneoplastic lesions (p > 0.05). Among 33 solitary tumors, 9 were malignant tumors and 24 were benign tumors. The majority of the parotid lesions were hypoechoic. The US feature that was most often associated with a benign lesion was distal acoustic enhancement. The US features that suggested malignancy were a heterogeneous echotexture, indistinct margins, and regional lymph node enlargement.

CONCLUSION

US can aid in the differentiation of parotid gland tumors, although benign and malignant parotid tumors often have a similar sonographic appearance.