Mixed neuroendocrine and adenocarcinoma of gastrointestinal tract: A complex diagnosis and therapeutic challenge

Core Tip

Core Tip: Mixed neuroendocrine and non-neuroendocrine neoplasms and mixed adeno-neuroendocrine cancer of the gastrointestinal system are a rare heterogeneous group of tumors with high malignant potential, rapid growth, and poor prognosis. The occurrence of cells with both neuroendocrine and non-neuroendocrine morphological features co-exist in varying amounts, and these tumors occur in almost all organs. The origin of these mixed cancers is not clearly defined but may be the result of certain genetic alterations and growth stimulation by the neuroendocrine peptides produced by neuroendocrine component. Regardless of the organ of origin, these tumors portend poor prognosis with increased proportion of neuroendocrine component. Multidisciplinary services and strategies are required for the management of these mixed malignancies to provide the best oncological outcomes.