R0 Resection for Stage IVc Appendiceal Goblet Cell Adenocarcinoma Diagnosed after Left Adnexectomy: A Case Report

The role of surgical resection in stage IV appendiceal goblet cell adenocarcinoma remains unclear. We report a case of a 44-year-old woman who underwent left adnexectomy for an ovarian tumor at another hospital. Pathological examination revealed not only an ovarian mature cystic teratoma but also goblet cell adenocarcinoma in the ovarian stroma, later diagnosed as appendiceal goblet cell adenocarcinoma with ovarian metastasis. Further evaluation suggested tumor invasion or metastasis to the rectosigmoid colon. Given the feasibility of curative resection, laparoscopic surgery was performed. Intraoperative findings confirmed rectal metastasis rather than direct invasion from appendiceal goblet cell adenocarcinoma. Peritoneal seeding to the greater omentum was confirmed intraoperatively, leading to total proctocolectomy with Hartmann's procedure, omentectomy, and right adnexectomy. Macroscopically, R0 resection was achieved. Pathological examination confirmed Grade 1 appendiceal goblet cell adenocarcinoma with metastases to the right ovary, rectosigmoid colon, and peritoneum. The patient received adjuvant chemotherapy and remains recurrence-free at 33 months postoperatively. This case highlights the importance of precise pathological assessment in ovarian tumors and suggests that aggressive surgical management may contribute to long-term survival, even in stage IV appendiceal goblet cell adenocarcinoma.