At a Centre of Excellence for neuroendocrine tumors, the expert histopathologist diagnosed a 12 mm NET at the tip of the appendix, immunostaining for pan-cytokeratins, synaptophysin, and chromogranin A, and showing L-cell differentiation with expression of glucagon and pancreatic polypeptide; the tumor was negative for serotonin. This evidence concerns the gene PPY and neoplasm.