The presence of individual neuroendocrine cells in rare peripancreatic lymph nodes (LNs) suggests that neuroendocrine tumor or nested neuroendocrine cell proliferation can arise in situ from neuroendocrine cells native to any LN.

However, it is very difficult to ascertain whether any neuroendocrine lesion in LNs is a primary tumor or a metastasis from adjacent organs.

Neuroendocrine lesion can be incidentally identified in ILNs. Close clinical follow-up is warranted as metastasis from or synchronous lesions in adjacent organs cannot be excluded.

References

 Small neuroendocrine lesions in intrathoracic lymph nodes of patients with primary lung adenocarcinoma: real metastasis? Li F, Wang X, Xu H, Roggli VL. Am J Surg Pathol. 2010 Nov;34(11):1701-7. PMID: 20871390