Yoshida Atsushi, Kohno Shigeshi, Oka Shojiro, Someya Yuko, Arizono Shigeki, Suga Tsuyoshi, Ishikura Reiichi, Itami Hiroe, Maeda Shinichiro, Ando Kumiko
Department of Diagnostic Imaging and Nuclear Medicine, Kyoto University, Kyoto, Japan.
Department of Diagnostic Radiology, Kobe City Medical Center General Hospital, Kobe, Japan.
Abdom Radiol (NY). 2025 Sep;50(9):4374-4379. doi: 10.1007/s00261-025-04882-3. Epub 2025 Mar 17.
Ovarian endometriotic cysts are associated with an increased risk of clear cell and endometrioid carcinomas, as well as borderline neoplasms. Although contrast-enhancing nodules on magnetic resonance imaging (MRI) suggest malignancy, benign endometriotic cysts can also present with such features, complicating differentiation from malignancy. When malignancy is suspected, minimally invasive procedures, such as laparoscopic cystectomy, are typically avoided. However, preserving fertility and ovarian function warrants careful consideration when selecting invasive surgical procedures. From the perspective of selecting appropriate surgical approaches, accurate preoperative differentiation between benign and malignant ovarian tumors is essential. We present the first case of MRI showing fallopian fimbriae entrapped in an endometriotic cyst mimicking malignancy. A 49-year-old female presented with atypical genital bleeding. MRI revealed a right ovarian endometriotic cyst with a contrast-enhancing mural nodule (10 mm), suggestive of malignancy. The nodule demonstrated T2-weighted hypointensity equivalent to the cyst fluid without diffusion restriction. Laparotomy revealed the nodule as entrapped fallopian fimbriae within the endometriotic cyst, with no malignancy detected. In this case, the fallopian fimbriae entrapped in the endometriotic cyst appeared as an enhancing nodule because of their vascularity, mimicking malignancy. Fallopian fimbriae are inconspicuous structures that can produce false findings suggestive of malignancy, similar to other benign enhancing nodules, such as polypoid endometriosis and decidualization. However, their lack of diffusion restriction and low T2-weighted signal intensity may help distinguish them from malignancy. This knowledge is crucial for accurate diagnosis and avoiding unnecessary interventions.
卵巢子宫内膜异位囊肿与透明细胞癌、子宫内膜样癌以及交界性肿瘤的风险增加有关。尽管磁共振成像（MRI）上的强化结节提示恶性，但良性子宫内膜异位囊肿也可能出现此类特征，这使得与恶性肿瘤的鉴别变得复杂。当怀疑为恶性时，通常会避免采用微创程序，如腹腔镜囊肿切除术。然而，在选择侵入性手术时，保留生育能力和卵巢功能值得仔细考虑。从选择合适手术方法的角度来看，准确的术前鉴别卵巢良性和恶性肿瘤至关重要。我们报告首例MRI显示输卵管伞陷入模仿恶性肿瘤的子宫内膜异位囊肿的病例。一名49岁女性出现非典型生殖器出血。MRI显示右侧卵巢子宫内膜异位囊肿伴有一个强化的壁结节（10毫米），提示恶性。该结节在T2加权像上呈低信号，与囊液信号相同，无弥散受限。剖腹探查显示该结节为陷入子宫内膜异位囊肿内的输卵管伞，未检测到恶性肿瘤。在本病例中，陷入子宫内膜异位囊肿的输卵管伞由于其血管丰富而表现为强化结节，并模仿恶性肿瘤。输卵管伞是不显眼的结构，可产生提示恶性肿瘤的假阳性结果，类似于其他良性强化结节，如息肉样子宫内膜异位症和蜕膜化。然而，它们缺乏弥散受限和低T2加权信号强度可能有助于将它们与恶性肿瘤区分开来。这些知识对于准确诊断和避免不必要的干预至关重要。
