Nonneuroendocrine

Nonneuroendocrine is a descriptive term used in medicine to designate tissues, cells, or neoplasms that do not originate from neuroendocrine cells or lack neuroendocrine differentiation. In pathology, this term is often used to distinguish nonneuroendocrine neoplasms from neuroendocrine neoplasms, such as neuroendocrine tumors (NETs) and neuroendocrine carcinomas (NECs).

Neuroendocrine cells are specialized cells that share features of neurons and hormone-secreting cells and are found throughout the body, including the gastrointestinal tract, pancreas, and lungs. Tumors arising from these cells are termed neuroendocrine neoplasms. By contrast, nonneuroendocrine lesions originate from other cellular lineages and typically lack neuroendocrine markers.

Diagnosis relies on histology and immunohistochemistry. Neuroendocrine differentiation is suggested by positivity for markers such as chromogranin A, synaptophysin, and CD56. Nonneuroendocrine lesions generally are negative for these markers and exhibit lineage-specific profiles (for example cytokeratin patterns of carcinomas or vimentin for sarcomas). Rare tumors may show focal neuroendocrine features, complicating classification and leading to categories such as mixed neuroendocrine–nonneuroendocrine neoplasms.

Clinical implications hinge on the tumor type rather than the absence of neuroendocrine differentiation. Management, prognosis, and surveillance are guided by the primary histogenesis (e.g., adenocarcinoma, squamous cell carcinoma) rather than by a nonneuroendocrine designation alone.

See also: neuroendocrine tumor; neuroendocrine differentiation; pathology.