Goblet or signet ring cells: that is the question.

Goblet cell carcinoid tumor is a rare mixed endocrine-exocrine neoplasm of the appendix. It carries an intermediate biologic behavior between a classic carcinoid tumor and a conventional adenocarcinoma. There has been a general lack of clinicopathologic parameters that can be reliably used to predict the clinical course and patient outcome. A recent retrospective study of a large number of appendiceal goblet cell carcinoids has shown that these tumors can be stratified into 3 subgroups based on careful histologic analysis: typical goblet cell carcinoid (group A); adenocarcinoma ex goblet cell carcinoid, signet ring cell type (group B); and adenocarcinoma ex goblet cell carcinoid, poorly differentiated carcinoma type (group C). Clinical follow-up data show that the histologic classification correlates with patient survival. Thus, meticulous histologic evaluation is of critical importance in determining the prognosis and guiding the management of patients with goblet cell carcinoids. This brief review summarizes these recent findings and raises a few issues that may need to be further addressed to better apply this classification to our practice.