Mucoepidermoid carcinoma of the esophagus with MAML2 gene rearrangement: Case report and literature review.

Mucoepidermoid carcinoma (MEC) is the most common salivary gland malignancy but rarely occurs in the esophagus. It is easily confused with adenosquamous carcinoma and squamous cell carcinoma (SCC) with mucus-secreting components. MAML2 gene rearrangement detected by fluorescence in situ hybridization (FISH), RT-PCR or next-generation sequencing (NGS) can aid in the diagnosis. We present a case of esophageal MEC with MAML2 gene rearrangement detected by FISH. To the best of our knowledge, this is the first report of an esophageal MEC with MAML2 gene rearrangement. We also reveal that esophageal MEC patients were reported to have a higher risk of recurrence and death than SCC patients in previous literature. However, all the cases were diagnosed using previous diagnostic criteria and not confirmed by MAML2 gene rearrangement detection, and most of them might not be true MECs.