含胎兒腸道分化之分泌甲胎蛋白（AFP）之卵巢透明細胞腺癌：罕見案例報告及系統性文獻回顧

Alpha-fetoprotein-producing ovarian clear cell adenocarcinoma with fetal gut differentiation: a rare case report and literature review

甲胎蛋白（AFP）是卵巢生殖細胞腫瘤，尤其是卵黃囊腫瘤（YST）的有用腫瘤標誌物，對診斷和進一步追蹤都很有價值。上皮性卵巢癌（EOC）很少分泌AFP，特別是對於透明細胞類型和停經後的女性。基於對產生AFP的透明細胞類型EOC的有限知識，對該主題的病例和文獻回顧進行了廣泛的綜述。一名55歲的停經後婦女經歷陰道點狀出血一個月，最初血清AFP值為60721ng／ml。組織學檢查是明確的細胞類型EOC。瘤細胞對於磷脂酰肌醇蛋白聚醣-3（GPC3）和AFP透露強烈免疫反應，肝細胞核因子-1β（HNF-1β）弱，但CD30陰性，使得診斷產生AFP的透明細胞型EOC與局灶性區域的兒腸道分化，FIGO（國際婦產科聯合會）分期IIIC。雖然患者接受了治療，包括最佳減積手術和多種化療藥物治療，但患者仍死於疾病。為了能了解產生AFP的透明細胞型EOC的臨床和分子特徵，我們進行了系統性的文獻回顧。共有三篇論文描述了可產生AFP的透明細胞類型EOC。這些病例的總生存率，包括目前的病例為50％。雖然常規診斷透明細胞型EOC並不需要免疫組織化學檢查，但要區別於其他腫瘤，尤其是生殖細胞腫瘤，或提供更好的方法來監測治療反應或評估疾病狀態，免疫染色，包括GPC3，HNF-1β，CD30，細胞角蛋白（CK）7或20，和AFP需要被考慮在內。由於案例數少，適當的化療方案和產生AFP的透明細胞型EOC的生物學行為仍不清楚。

Alpha-fetoprotein (AFP) is a useful tumor marker for ovarian germ cell tumors, particularly yolk sac tumor (YST). It is valuable for both diagnosis and further follow-up. Epithelial ovarian carcinoma (EOC) rarely secretes AFP, especially for clear cell type and in the postmenopausal women. Based on the limited knowledge about AFP-producing clear cell type EOC, a case and literature review on this topic is extensively reviewed. We report a 55-year-old postmenopausal woman experienced vaginal spotting for one month, and serum level of AFP was 60721 ng/ml initially. Histological examination was clear cell type EOC. Tumor cells revealed strong immune-reactivity for glypican-3 (GPC3) and AFP and weak for hepatocyte nuclear factor-1beta (HNF-1 beta), but negative for CD30, making the diagnosis of AFP-producing clear cell type EOC with fetal gut differentiation in focal areas, FIGO (International Federation of Gynecology and Obstetrics) IIIc. Although the patient underwent an intensive treatment, including optimal debulking surgery and multi-agent chemotherapy, the patient died of disease. To provide a better under standing of clinical and molecular characteristics of the AFP-producing clear cell type EOC, we conducted a systematic literature review. A total of three papers described the AFP-producing clear cell type EOC are available. The overall survival rate of these cases, including the current case is 50%. Although immuno-histochemical examination is not always needed in routine for the diagnosis of clear cell type EOC, to distinguish from other tumors, especially germ cell tumors, or to provide the better way to monitor therapeutic response or to evaluate the disease status, immunostaining, including GPC3, HNF-1 beta, CD30, cytokeratin 7 or 20, and AFP is taken into account. Due to rarity, the appropriate chemo-therapy regimen and the biological behavior of AFP-producing clear cell type EOC are still unclear.