Department of Radiology, Tokushima University, Tokushima, Japan.
Department of Radiological Technology, Tokushima Bunri University, Sanuki, Kagawa, Japan.
J Obstet Gynaecol Res. 2022 Oct;48(10):2583-2593. doi: 10.1111/jog.15367. Epub 2022 Jul 22.
Polypoid endometriosis is a rare variant of endometriosis and may mimic malignancy. The purpose of this study is to evaluate magnetic resonance (MR) imaging characteristics of polypoid endometriosis for the differential diagnosis with malignancy.
MR imaging findings of four histologically proven polypoid endometriosis were retrospectively evaluated with the review of the literature.
All polypoid endometriosis exhibited high signal intensity on T2-weighted images reflecting abundant dilated endometrial glands. Peritoneal lesions were surrounded by low signal intensity rim represented the "black rim sign" reflecting endometriotic fibrous adhesion. Two cases arising from endometriotic cysts showed transmural extension (peritoneal extension and myometrial infiltration). Endometriotic hemorrhagic foci were demonstrated in four lesions as high signal intensity on T1-weighted images and/or susceptibility-induced signal voids on susceptibility-weighted MR sequence. Diffusion-weighted images showed high signal intensity with relatively high apparent diffusion coefficient (ADC) due to T2 shine-through effect but no diffusion restriction, and dynamic contrast-enhanced (DCE) MR imaging showed gradually increasing contrast-enhancement pattern like benign pathologies.
Polypoid endometriosis may mimic malignancy; however, black rim sign may be a characteristic MR imaging finding for the peritoneal lesions, and no diffusion restriction and gradually increasing contrast-enhancement pattern may reflect its benign nature.
息肉状子宫内膜异位症是一种罕见的子宫内膜异位症变异，可能类似于恶性肿瘤。本研究旨在评估息肉状子宫内膜异位症的磁共振成像（MR）特征，以进行鉴别诊断。
回顾性分析了 4 例经组织学证实的息肉状子宫内膜异位症的 MR 成像表现，并复习了相关文献。
所有息肉状子宫内膜异位症在 T2 加权图像上均显示高信号强度，反映了丰富的扩张子宫内膜腺体。腹膜病变周围有低信号强度边缘，代表“黑边征”，反映了子宫内膜纤维粘连。2 例起源于子宫内膜囊肿的病变表现为壁内延伸（腹膜延伸和子宫肌层浸润）。4 例病变均显示子宫内膜出血灶在 T1 加权图像上呈高信号强度，并且在磁敏感加权 MR 序列上呈磁敏感诱导的信号缺失。扩散加权图像显示高信号强度，由于 T2 透过效应，表观扩散系数（ADC）相对较高，但无弥散受限，动态对比增强（DCE）MR 成像显示逐渐增强的增强模式，类似于良性病变。
息肉状子宫内膜异位症可能类似于恶性肿瘤；然而，黑边征可能是腹膜病变的特征性 MR 成像表现，无弥散受限和逐渐增强的增强模式可能反映其良性性质。
