SYP and neuroendocrine carcinoma: Cytokeratins, chromogranin, and synaptophysin, as well as several peptides such as calcitonin and VIP, which are more regularly expressed in NEC (1) and the lack of immunolabeling for some cytoskeletal proteins such as neurofilament, class III beta-tubulin isotype and MAP-2 in human NEC are suggested to be the main differences between NEC and ONB (2, 39).