Imaging features of acinic cell carcinoma: three case reports and a review of the literature

Abstract

Objectives. The purpose of this study was to investigate the imaging characteristics of acinic cell carcinoma in three patients and to present a review of the relevant literature. Methods. The tumor site, shape, size, boundary, internal homogeneity and density, and appearance of contrast enhancement were evaluated in three patients with histologically proven acinic cell carcinoma using computed tomography (CT), magnetic resonance (MR), or ultrasonography (US) images. Through a review of the literature, imaging features are summarized. Results. Acinic cell carcinoma frequently occurred in the parotid gland. The shape and size were various. The tumor was well-circumscribed and homogeneous if there was no cyst, hemorrhage, or calcification within the tumor. Most lesions showed low and high signal intensities on T1 and T2-weighted MR images, respectively. The tumor was slightly or peripherally enhanced by the contrast medium. Conclusions. Acinic cell carcinoma has often been described as a well-circumscribed and homogeneous mass. Even if the tumor in the parotid gland shows benign features on imaging, we should consider acinic cell carcinoma as part of the differential diagnosis.