Mucoepidermoid carcinoma of the base of tongue:A case report and literature review

Abstract Purpose Mucoepidermoid carcinoma originates from reserve cells present in ducts of salivary glands and is the most common malignancy of the salivary glands, commonly found in the parotid gland, followed by the palatal and buccal mucous membranes. However, mucoepidermoid carcinoma occurrence in other intraoral sites, including the tongue base, is extremely rare. Methods A 33-year-old man presented with a progressively enlarging mass of the left tongue base. Contrast-enhanced computed tomography and magnetic resonance imaging revealed an enhancing ill-defined soft tissue mass in the left jaw region with cervical lymph node enlargement of unknown nature, without evidence of distant metastasis. Transoral needle biopsy from the mass revealed low-grade mucoepidermoid carcinoma pathologically. Complete transoral excision and cervical lymph node dissection were performed, following by tongue and mouth floor defects reconstruction with anterolateral thigh free flap. Examination of the obtained surgical specimen confirmed low-grade MEC with MAML2 gene fusion in the base of tongue. The tumor was removed with negative margins and cervical lymph nodes. Results The patient had an uneventful recovery and no evidence of recurrence or metastasis by 40 months of follow-up. Conclusion We present a rare case of mucoepidermoid carcinoma at the tongue base. Furthermore, we review related literature, and discuss its clinical features, histopathological characteristic, and treatment strategist.