[Imaging findings in 12 cases of Warthin-like mucoepidermoid carcinoma]

To summarize the ultrasound, CT and MRI manifestations of Warthin-like mucoepidermoid carcinoma (WT-MEC), and to explore its imaging characteristics, so as to provide reference for clinical and preoperative diagnosis.

The clinical information and imaging data of ultrasound, CT and MRI of 12 patients with WT-MEC diagnosed by pathology in Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine from January 2017 to December 2021 were collected, and their specific characteristics were retrospectively summarized.

Among the 12 WT-MEC patients, there were 7 males and 5 females, with an average age of (42.7±16) years. Seven cases underwent ultrasound examination, 6 cases underwent CT examination, and 2 cases underwent MRI examination. Radiologically, all the lesions presented as a solitary mass. 11/12 lesions(91.7%) were identified as well-defined margins, and 10/12(83.3%) as solid-cystic masses. All solid-cystic lesions contained multiple cystic areas with variable sizes. On US images, most lesions showed mixed-echoic echogenicity(5/7, 71.4%), poor vascularization (6/7, 85.7%) and acoustic enhancement (6/7, 85.7%). CT revealed all the lesions (6/6, 100%) as a soft-tissue mass with heterogeneous enhancement (5/6, 83.3%). MRI imaging demonstrated the neoplasm with low or iso-signal intensity on plain T1WI and hyperintensity on T2WI. The heterogeneous enhancement was shown on contrast-enhanced T1WI.

Most WT-MECs represent as a solitary, well-defined, solid-cystic mass in the parotid gland. The neoplasm may be characterized by the multiple and variable-sized cystic components within the tumor.