Combined goblet cell carcinoid and mucinous cystadenoma of the vermiform appendix.

Goblet cell carcinoid is an uncommon primary tumor of the vermiform appendix, characterized by dual endocrine and glandular differentiation. Whether goblet cell carcinoid represents a morphological variant of appendiceal classical carcinoid or a mucin-producing adenocarcinoma is a matter of conjecture. Rare cases of goblet cell carcinoid with other concomitant appendiceal epithelial neoplasms have been documented. In this report, we describe a rare case of combined appendiceal goblet cell carcinoid and mucinous cystadenoma, and discuss the possible histopathogenesis of this combination.