目的:探讨卵巢伴环状小管性索肿瘤的临床病理特点、免疫组化表型特征及鉴别诊断。方法:收集临床遇到的3例卵巢伴环状小管性索间质瘤进行分析,观察其组织学、免疫组织化学的特征,并结合相关文献探讨其临床病理学特征及预后。结果:瘤组织以单纯或复杂的环状小管包绕玻璃样物质为特征,单纯性小管形状如同一个环,复杂的小管数量多,形成相互交通的“大环套小环”的环状结构;免疫组化结果:α-抑制素阳性、CD99阳性,AFP阴性,EMA阴性,Ki-67阳性率均小于5%。特殊染色:PAS阳性。结论:卵巢环状小管性索肿瘤罕见,但具有特异的组织学特征和免疫表型,需与性腺母细胞瘤、颗粒细胞瘤、Sertoli细胞瘤、类癌鉴别。 OBJECTIVE: To investigate the clinicopathological features, immunohistochemical phenotype and differential diagnosis of ovarian cancer with annular tubulointerstitial tumor. Methods: Three cases of ovarian accompanied with annular tubulointerstitial tumor were collected for clinical analysis. The histological and immunohistochemical characteristics were observed. The clinicopathological features and prognosis were also analyzed. Results: The tumor tissue was characterized by simple or complex annular tubules surrounding the glass-like material. The simple tubule shape was like a ring, and the number of complex tubules was more than that of the “small ring” The results of immunohistochemistry showed that α-statin was positive, CD99 was positive, AFP was negative, EMA was negative, Ki-67 positive rates were less than 5%. Special stain: PAS positive. Conclusions: The ovarian loop-like tubular tumors are rare, but have special histological features and immunophenotypes, which need to be differentiated from gonadoblastoma, granulosa cell tumor, Sertoli cell tumor and carcinoid.