Published online Dec 15, 2024. doi: 10.4251/wjgo.v16.i12.4738
Revised: October 5, 2024
Accepted: October 22, 2024
Published online: December 15, 2024
Processing time: 104 Days and 11.9 Hours
Pancreatic mixed neuroendocrine-non-neuroendocrine neoplasms (MiNENs) are rare malignancies affecting the pancreas. The World Health Organization defines MiNENs as neoplasms composed of morphologically recognizable neuroendocrine and non-neuroendocrine components, each constituting 30% or more of the tumor volume. Adenocarcinoma-neuroendocrine carcinoma is the most fre
Here we report a rare case with intermingled components of ductal adenocarcinoma and grade 1 well-differentiated NET in the pancreas. The two tumors show distinct histology and significant differentiation discrepancy (poorly differentiated high grade adenocarcinoma and well-differentiated low grade NET), and also present as metastases in separate lymph nodes. Next generation sequencing of the two components demonstrates KRAS and TP53 mutations in the ductal adenocarcinoma, but no genetic alterations in the NET, suggesting divergent origins for these two components. Although tumors like this meet the diagnostic criteria for MiNEN, clinicians often find the diagnosis and staging confusing and impractical for clinical management.
Mixed NET/non-NET tumors with distinct histology and molecular profiles might be better classified as collision tumors rather than MiNENs.
Core Tip: Pancreatic mixed neuroendocrine-non-neuroendocrine neoplasms (MiNENs) are rare malignancies affecting the pancreas, recognized by the World Health Organization as neoplasms composed of morphologically recognizable neuroendocrine and non-neuroendocrine components, each constituting ≥ 30% of the tumor volume. However, whether the tumor should be classified as a MiNEN or collision tumor when there is clear divergence in histology and molecular profiles for each component is still debatable. This paper reports a rare case with high grade adenocarcinoma admixed with low grade neuroendocrine tumor in pancreas, which are demonstrated to have distinct molecular profiles. We discuss the potential impacts of tumor classification on staging and clinical management, hoping to encourage more discussions and studies on this rare entity.