NCAM1 and neuroendocrine carcinoma: The adjacent solid and trabecular component (corresponding to the area within the yellow outline in Figure 2) was composed of tumor cells showing elongated hyperchromatic nuclei and scant cytoplasm (Figure 3a and c), which were immunoreactive for CD56 (Figure 3b) and synaptophysin, confirming the diagnosis of neuroendocrine carcinoma (NEC).