A Rare Case of Metastatic Poorly Differentiated Neuroendocrine Tumor Arising From the Sigmoid Colon in an Active Duty Service Member.

Neuroendocrine tumors (NET) are rare malignancies that contain neural and endocrine cells with a median age of diagnosis of 63 years. NETs are typically located in the gastrointestinal (GI) tract, the pancreas, or the lungs. Within the GI tract, the most common locations for NETs are the small bowel, appendix, or rectum.