[Esophageal NEN: update on diagnostics and surgical treatment]

Neuroendocrine neoplasms (NEN) of the esophagus are rare biologically heterogeneous tumors predominantly with aggressive courses. The World Health Organization (WHO) classification 2019/2022 distinguishes between well-differentiated neuroendocrine tumors (NET), poorly differentiated neuroendocrine carcinomas (NEC) and mixed neuroendocrine/non-neuroendocrine neoplasms (MiNEN), a differentiation with direct therapeutic consequences. The vast majority of esophageal NENs are poorly differentiated NECs with a corresponding unfavorable prognosis. The diagnostics require an extended immunohistochemical panel, synaptophysin, CgA, INSM1, Ki-67, TTF‑1 and a complete investigation of predictive biomarkers, including PD-L1, dMMR/MSI and NGS, ideally even in the primary diagnostic facility. The functional imaging depends on the histological subtype: ⁶⁸Ga-DOTATATE (or DOTATOC, 18F-SiTATE) PET for NET G1/G2, ¹⁸F‑FDG-PET/CT for G3 NET/G3 NEC. Both procedures can be useful in the transitional range of G2 and G3 NET. Surgical resection, which is usually minimally invasive Ivor Lewis esophagectomy with D2 lymphadenectomy after neoadjuvant systemic treatment, is still the cornerstone of curative treatment for resectable disease. The concentration on certified centers with expertise in both esophageal surgery and NEN treatment is a prerequisite for an adequate treatment. In cases of nonresectable or metastatic disease platinum-etoposide-based regimens are the standard treatment. Definitive chemoradiotherapy represents an equivalent alternative for inoperable advanced cases. Due to the lack of prospective data all therapeutic recommendations must be considered an expert consensus.