耳鼻科ジャーナル

MR Imaging Features of Minor Salivary Gland Tumors

Amit Karandikar, Siu Cheng Loke, Julian Goh and Tiong Yong Tan

Aim: To retrospectively evaluate the MR imaging features of histologically proven minor salivary gland tumors (MSGTs). Materials and Methods: A retrospective review of MR imaging features of 29 histologically proven MSGTs was performed. Results: The commonest site of involvement was base of tongue (n=7) and the commonest pathology was adenoid cystic carcinoma (n=12). All the MSGTs revealed smooth surface with well-defined margins and polypoidal appearance (100% sensitivity, 100%PPV). T2w hyperintensity and enhancement results (ranged from intense to intermediate hyperintensity) were variable. Larger tumors (more than 3.5 cm) had a heterogeneous appearance. Discussion: All MSGTs showed smooth surface, well-defined margins and polypoidal appearance. The T2w hyperintense signal of the MSGTs (ranging from intermediate T2w hyperintensity to intense T2w hyperintensity) and the post contrast enhancement (also ranging from intermediate to intense enhancement) was variable. In the head and neck region, MSGTs need to be differentiated from the more common entities such as squamous cell ancers (SCC) and Lymphoma. While this differentiation is not always easy, orphologically SCCs typically present as locally infiltrative tumors with ill-defined margins. Lymphomas typically present as polypoidal masses with well-defined margins and hence may closely resemble MSGTs. Lymphomas are generally homogeneous masses showing intermediate T2w hyperintensity. Thus differentiation between lymphomas and MSGTs can sometimes be a challenge, however if the mass shows intense T2w hyperintensity with intense enhancement, it could point to a diagnosis of MSGT.