女，50岁，卵巢和腹腔多发性肿瘤。

大体：鱼肉状肿瘤，坏死不明显。

9年前，“卵巢交界性浆液性肿瘤”手术史。无法查找原切片。

免疫组化：Vimentin+，最后一图为CD117阳性，但DOG1和CD34阴性。不知如何解释？

其余阴性：CK，EMA，CK8，CK18，CK7，CK20，Villin，S100，LCA，PLAP，CD99，α-Inhibin，Calretinin，Syn，CgA，CD56，SMA，Desmin，CD10，ER，PR

以上抗体都有对照

考虑纤维肉瘤，但CD117阳性难以解释。请大家指教，谢谢！

 Excellent history, gross description and beautiful photos!

 Given the clinical presentation of multiple tumors in the ovary and abdominal cavity as well as c-kit positivity, an intraabdominal GIST involving ovary should be considered. You have done a relatively complete panel of IHC so far. The CD117 positivity per se is by no means specific since it can be seen in many other tumors besides GIST. However, the immunoprofile you have done essentially excludes the commonly seen spindle cell neoplasms of the ovary, such as granulosa cell tumor, fibrothecoma, poorly differentitated sex-cord stromal tumor, endometrial stromal sarcoma and leiomyosarcoma. CD117 is usually negative in these tumors I just mentioned. However, there are couple ovarian neoplasms demonstrated relatively high percentage of c-kit positivity. Notoriously known is the dysgerminoma of the ovary with the similar CD117 positivity pattern seen in testicular seminoma. Your PLAP negativity and morphology exclude this possibility. On the other hand, lack of CD34 should not exclude dx of GIST since not all GIST (only about 85%) showing immunoreactivity to CD34.

谢谢两位专家指导！

我的疑惑是，暂不考虑形态学，仅分析免疫组化的表达，在DOG1和CD34都不表达的情况下，仅CD117表达，能否诊断胃肠道（外）间质瘤？卵巢组织可表达CD117，卵巢纤维肉瘤是否也可以表达？

诊断：恶性肿瘤，免疫组化提示胃肠道间质瘤（高度危险程度）可能性大。建议做分子学检测。

照片很漂亮！