Goblet Cell Carcinoid, Group A
This is an example of typical goblet cell carcinoid (GCC) showing well-defined clusters of goblet cells lacking significant cytologic atypia infiltrating the muscular wall of the appendix. There is no desmoplastic response. This would be classified as typical GCC, group A, according to the classification proposed by Tang et al (Am J Surg Pathol 2008; 32:1429-1443). GCC's show mixed phenotype, with neuroendocrine as well as goblet cell (glandular) differentiation. They are considered to be distinct from both classic carcinoids of the appendix as well as de novo appendiceal adenocarcinomas.