Practical hints for the diagnosis of mixed neuroendocrine-non-neuroendocrine neoplasms of the digestive system

Figure 1 Diagnostic algorithm for the distinction of mixed neuroendocrine and non-neuroendocrine neoplasm. Mixed neuroendocrine and non-neuroendocrine neoplasm needs to be distinguished from neoplasms with focal neuroendocrine aspects like paraganglioma, non-neuroendocrine neoplasm with single neuroendocrine marker expression, neoplasm with interspersed neuroendocrine cells, or amphicrine neoplasm. ¹The definition of scattered cells includes, but is not exclusive of, other appearances like sheets, ribbons, micronodules, or insulae. MiNEN: Mixed neuroendocrine and non-neuroendocrine neoplasm; NE: Neuroendocrine; NEN: Neuroendocrine neoplasm.