Navale P, et al. - Twenty-five cases from the Design The pathology databases from three large academic medical centers were identified by the researchers in order to partition the oral vault into the oral cavity proper and the oropharynx on the basis of an awareness that these compartments are distinct, and to hypothesize that comparable tumor types arising from these compartments may behave in dramatically distinctive ways. Neck node dissections was performed in 19 patients. Thirteen had histologically documented lymph node metastases. Mucoepidermoid carcinoma (MECs) that lacked high-grade characteristics were almost as prone to metastasize as those with high-grade characteristics. The MAML2 gene fusion was harbored by two of three metastases tested. Thus, MECs arising from the base of the tongue are correlated with an alarmingly high rate of nodal metastases. This behavior cannot be prognosticated by histologic grading or MAML2 status. Moreover, the propensity to metastasize may to some degree indicate the unique microenvironment of the oropharynx.