Neuroendocrine Tumors of the Esophagus: State of the Art in Diagnostic and Therapeutic Management

Introduction Neuroendocrine tumors (NETs) are a heterogeneous group of neoplasms composed of cells containing dense-core neuroendocrine secretory granules in their cytoplasm. NETs of the esophagus are exceedingly uncommon, with a parallel absence of data published on clinical features, prognosis, and proposed treatment strategies. Methods As relevant classification is not well-established, knowledge acquired in NETs of lung and gastrointestinal sites usually guides esophageal NET management. Associated subtypes are divided based upon shared neuroendocrine features into small and large cell NET, typical and atypical carcinoid. Results Common presenting symptoms include dysphagia, abdominal discomfort, weight loss, melena, and on occasion, signs of carcinoid syndrome. Endoscopic findings describe a polypoid, nodular elevated lesion with an overlying surface depicted as mostly smooth and glistening. Disease metastasis is assessed using anatomical imaging, including computed tomography (CT), endoscopic ultrasonography (EUS), and positron emission tomography (PET)-CT. Prognosis is influenced by the extent of lymph node metastasis and potential lymphovascular invasion. Furthermore, proliferative activity, estimated using mitotic count or Ki-67 immunostaining, has been suggested as a significant prognostic parameter. Conclusion Therapeutic approach depends on clinical staging. Nevertheless, currently, a specific treatment algorithm for esophageal NETs has not been elucidated. Endoscopic resection has been proposed in NETs less than 1 cm in size with absence of regional lymph node metastasis, while surgical excision combined with adjuvant chemotherapy remains the treatment of choice.