Pancreatic tumors chromogranins

FIGURE 10.38 Distribution of markers in pancreatic endocrine tumors. SYN, synaptophysin NSE, neuron-specific enolase LMWCK, low-molecular-weight cytokeratin CgA, chromogranin A PC2, pro-convertase 2 PCM, peptidylglycine alpha-amidating enzyme PC3, proconvertase 3 NFP, neurofilament protein HCC(a), human chorionic gonadotropin alpha VIM, vimentin. 

Kimura N, Pilichowska M, Okamoto H, et al. Immunohistochemical expression of chromogranins A and B, prohormone convertases 2 and 3, and amidating enzyme in carcinoid tumors and pancreatic endocrine tumors. Mod Pathol. 2000 13 140-146. 

A. Other useful positively staining antibodies include CD56 (NCAM), CD57 (Leu7), and NSE. NESP-55, a member of the chromogranin family, is a promising marker of pancreatic neuroendocrine tumors, but it is... 

DAs are typically negative for pancreatic enzymes such as trypsin, chymotrypsin, and lipase °76 unless there is a mixed acinar component, which is uncommon. They also fail to label with endocrine markers however, in 30% of DAs there are scattered, possibly non-neoplastic, endocrine cells in close association with the neoplastic cells, which can be highlighted with immunostains for chromogranin A, synaptophysin, and NSE.2 2 77-79 latter two markers can occasionally show more diffuse expression, which should not be regarded as evidence of neuroendocrine differentiation if the tumor is an otherwise conventional adenocarcinoma. 

Pancreatic endocrine neoplasm versus ACC Scattered endocrine cells or a focal endocrine component are common in ACC however, diffuse and strong reactivity for the endocrine markers (chromogranin and synaptophysin) throughout the tumor is characteristic of PENs. Additionally, PENS do not show immunoreactivity for acinar markers. 

This is one differential in which immunohistochemistry can be of utmost importance. Numerous cytologic and architectural similarities exist between HCC and metastatic well-differentiated neuroendocrine neoplasia (carcinoids and pancreatic endocrine neoplasia) They are both cellular, stroma-poor tumors that have a delicate sinusoidal vasculature and relatively monotonous cells with fair amount of cytoplasm and round nuclei. A panel of "neuroendocrine markers" (chromogranin, synapto-physin, and CD56) combined with "hepatocytic" markers (Hep Par-1 and polyclonal-CEA, and FISH for albumin) can be helpful. 

---