Primary hepatic neuroendocrine tumor with a suspicious pulmonary nodule: A case report and literature review

Table 3 Commonly used immunohistochemical markers in neuroendocrine neoplasms[68-71]

Immunohistological markers	Interpretation
Chromogranin A	The major constituents of neuroendocrine secretory granules, the first-choice marker to confirm nets, responding prognosis
Synaptophysin	The main constituent of synaptic vesicles of neurons, most sensitive but no specific nets marker
Neuron-specific enolase	A glycolytic enzyme produced in neurons and neuroendocrine cells, with low sensitivity and specificity
CD56	The neural cell adhesion molecule, a sensitive but no specific neuroendocrine marker
ASH1	The key transcription factor in neuroendocrine cell differentiation, used as a differential diagnosis for high-grade extra-pulmonary NECs[68,69]
CK AE1/AE3	Marking the epithelial and epithelial-derived tumors[61,70]
SSTR 2/5	The most frequently expressed SSTR subtypes in NENs, with type-specific differences[71]

ASH1: Achaete-scute homolog-1; CD: Cluster of differentiation; CK AE1/AE3: Cytokeratin AE1/AE3; NECs: Neuroendocrine cancers; NENs: Neuroendocrine neoplasms; SSTR: Somatostatin receptor.