Mixed neuroendocrine-non-neuroendocrine tumors arising in residual gastric with multiple gene mutations: a case report

Background: Mixed Neuroendocrine-Non-Neuroendocrine Tumors (MiNENs) are a class of rare malignancies, and the pathogenesis remains obscure. The rarity of this condition has impeded the development of a standardized therapeutic approach. Case presentation: Here, we present the case of a patient diagnosed with gastric MiNENs post-gastrectomy, underwent a partial gastrectomy. The patient exhibited a complex genetic profile, marked by multiple gene mutations, and demonstrated elevated levels of Programmed Death Receptor Ligand 1 (PD-L1). The treatment regimen included etoposide, carboplatin, and sintilimab and the patient is currently in tumor-free survival. Conclusions: Our report shows that MiNENs could arise in residual gastric with multiple gene mutation, and surgery combining with chemotherapy and immunotherapy should be adopted.