Cervical and endometrial metastases of appendiceal goblet cell carcinoid

Appendiceal goblet cell carcinoid (GCC) is a rare tumor with histologic features of both adenocarcinoma and neuroendocrine tumor (carcinoid). Clinically, it behaves more aggressively than classic appendiceal carcinoid and commonly presents with peritoneal carcinomatosis. We report 2 cases of appendiceal GCC, one with uterine cervical involvement and the other with endometrial involvement as the initial presentations. The first patient's invasive cervical signet ring cell carcinoma was diagnosed on routine screening. The second patient presented with abnormal uterine bleeding, and endometrial curettage showed an adenocarcinoma with signet ring cell features. Primary appendiceal GCC was demonstrated in both cases after systematic clinical investigations. Metastatic appendiceal GCC to uterine cervix and endometrium can potentially be misinterpreted as primary cervical or endometrial signet ring cell carcinoma. Therefore, for any uterine cervical/endometrial signet ring cell carcinoma, a metastatic appendiceal GCC should be considered in the differential diagnosis, especially after excluding other primary sites.