The magnetic resonance imagings of pleomorphic adenoma with pathological correlation

Abstract

There is great variability in the MR findings of pleomorphic adenoma, which are the most common tumors of the parotid gland, reflecting the various proportions of cellular. mvxoid. and fibrosis components.
The purpose of our study was to correlate the magnetic resonance (MR) features and histopathological findings of pleomorphic adenoma and to interpret these findings. We reviewed MR studies of 60 pathologically proven pleomorphic adenoma. Forty-five cases (75%) showed high signal intensity for the normal parotid gland on T2-weighted images. The diagnostic clue of pleomorphic adenoma is to find the myxoid component, which shows a high intensity on T2-weighted images. Nine cases (15%) showed iso or hypo intensity on T2-weighted images. Six cases (10%) showed hypointensity on T2-weighted images, reflecting fibrosis. We speculated that hypercellularity with less myxoid stroma reduced the intensity on T2-weighted images.
Although it has been reported that pleomorphic adenomas typically have a high signal intensity on T2-weighted images, 25 % cases of pleomorphic adenoma demonstrated iso intensity or hypo intensity in this study.
It is likely that understanding these relationships between T2-weighted signal in MRI and pathological findings will improve diagnosis of parotid pleomorphic adenoma.