Different histological subtypes of parotid gland tumors: CT findings and diagnostic strategy.

Aim: To present computed tomography (CT) findings of different histological subtypes of parotid gland masses in detail and to establish diagnostic strategy.

Methods: From January 2009 to November 2011, 56 patients were collected through the histopathology and Picture Archiving and Communication Systems records, which revealed 5 basal cell adenoma (BCA), 16 pleomorphic adenoma (PA), 25 Warthin's tumor (War-T), 3 Kimura's disease (KD) and 7 parotid carcinoma (PCa) cases. All the CT images were retrospectively analyzed by two radiologists in consensus, based on their description of morphology (location, number, size, margin and fibrous capsule) and enhancement patterns of masses. In addition, the diagnostic efficiency of diagnostic strategy is tested.

Results: War-T and BCA patients' mean age was 59.9 ± 12.6 years and 58.4 ± 18.2 years; the significant difference was seen in War-T vs PA and BCA vs PA. About 40% of War-Ts presented with bilateral multifocal lesions, a higher ratio than others. Seventy two percent of War-Ts were limited to the superficial lobe, followed by BCA 60% and PA 40%. Vessel facing sign and enlarged lymph nodes were both frequent in War-T, which respectively accounts for 84% and 76% of cases. Rapid contrast enhancement and decreases were unique for War-T. BCA and PA showed obvious delayed enhancement. The diagnostic strategy of parotid gland tumor had a good diagnostic efficiency, with high accuracy, sensitivity and specificity.

Conclusion: Determination of the histological subtypes of parotid gland masses might be possible based on CT findings and clinical data. A diagnostic strategy with high diagnostic efficiency was established.