An immunodiagnostic package based on immunohistochemical (IHC) technology for the detection of neuroendocrine tumors (NETs). The package focuses primarily on measuring the expression of Synaptophysin, a vesicular membrane protein found in the synaptic vesicles of neurons and endocrine cells, making it a highly sensitive marker for these tumors. The package also includes testing for Chromogranin A (a qualitative marker for dense secretory granules), CD56 (NCAM), and epithelial cell markers such as cytokeratin (Pan-CK). The package aims to confirm the histological diagnosis of NETs and provide information on the degree of differentiation (low versus high grade).