Mixed Adenoneuroendocrine Carcinoma of the Esophagus: A Case Report and Review of the Literature.

The most frequent presentation of esophageal cancer is adenocarcinoma and squamous cell carcinoma. In recent years, the latter has decreased its incidence increasing the adenocarcinoma. Currently, another type of tumor with a much lower incidence has been described, which has a neuroendocrine component along with another exocrine glandular component and has been classified since 2010 as mixed adenoneuroendocrine carcinoma (MANEC). We present the case of a 68-year-old male with a history of dyspepsia and epigastric pain who after performing a gastroscopy, was diagnosed with a malignant neoplasm of the esophagus. The patient underwent a total esophagectomy with reconstruction by tubular gastroplasty with cervical anastomosis. The final result of the piece after immunohistochemistry revealed that the tumor was composed of one component of adenocarcinoma in 60% together with another component compatible with neuroendocrine in 40%. With these findings and according to the World Health Organization classification of 2010 was diagnosed as esophageal MANEC. MANECs are rare tumors, described in other locations of the digestive tract, the esophagus being an infrequent location. Its preoperative diagnosis is difficult, and it is not until the final analysis of the complete piece by means of specific immunohistochemical techniques when its diagnosis can be established. Its treatment is fundamentally surgical, whereas the adjuvant therapeutic schemes with chemotherapy are not well defined at present because of their low incidence.