Non-squamous Tumors of the Oropharynx and Oral Cavity: CT and MR Imaging Findings with Clinical- Pathologic Correlation

Non-squamous cell neoplasms (non-SCCs) are rare tumors of the oropharynx and oral cavity. They can be of many different histologic types, either benign or malignant, including in decreasing order of frequency minor salivary gland tumors, lymphoma, mesenchymal tumors, melanoma, and metastases. Unlike squamous cell carcinoma, non-SCCs could remain unidentified on clinical examination/endoscopy, because they usually manifest as submucosal masses without mucosal alterations. Diagnostic imaging, as CT and, more accurately, MR, plays an essential role in the work-up of these neoplasms, mainly in the staging and follow-up. Furthermore, radiologic features can, to a certain extent, help evaluate a lesion as more likely benign or malignant. More significantly, although generally non-specific, they can suggest or even allow the correct diagnosis in some cases, as pleomorphic adenoma, lymphoma, lipoma, hemangioma, neurofibroma, liposarcoma, and melanoma, especially if integrated with clinical/endoscopic findings and histologic knowledge. In this article, we illustrate CT and MR features of oropharyngeal and oral cavity non-SCCs taken from our experience, with clinical-histologic correlation, and review the literature on the topic.