Appendiceal Goblet Cell Carcinoma: Comparison of Classification and Staging Systems with Evaluation of the Prognostic Role of Immunohistochemistry Stains

Background Goblet cell carcinoma (GCC) of the appendix is a unique lesion that exhibits features of both adenocarcinoma and neuroendocrine tumors. Due to the rarity of this cancer, multiple grading (e.g., Tang, Yozu, and Lee) and staging systems (e.g., tumor, lymph nodes, and metastasis [TNM]) have been developed for classification. This study aimed to compare commonly used classification systems and evaluate the prognostic effectiveness immunohistochemical staining may or may not have for appendiceal GCC. Methods An electronic medical records review of patients who were diagnosed with GCC of the appendix in our hospital system from 2010 to 2020. The data were collected regarding the age at diagnosis, gender, initial diagnosis at presentation, operation(s) performed, final pathology results, current survival status, and year of recurrent disease or death year. Results Ten patients were evaluated. Seventy percent of the patients were above the age of 50 years at diagnosis. Postdischarge survival ranged from 1 month to 109 months postdiagnosis. Two patients expired from GCC at 13- and 54-months following diagnosis. When comparing the classification systems, Lee categorized more patients as high risk than Tang and Yozu. Immunohistochemical staining was analyzed using four staining methods: Ki67, E-cadherin, Beta-catenin, and p53. Tumor, lymph nodes, and metastasis staging has supportive evidence for worsening prognosis and overall survival secondary to the depth of invasion of the tumor. Conclusion Tumor, lymph nodes, and metastasis staging may be superior to the other classification systems in predicting overall mortality. Our study demonstrated that immunohistochemistry staining does not appear to have a significant impact in determining the prognosis for GCC of the appendix.