Ovarian teratomas are found in one-third of females presenting with anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis. When a teratoma is detected on imaging, its removal is first-line therapy. Even with multiple imaging modalities, occasionally, the teratoma is found only on subsequent imaging, long after initial presentation. Very rarely, patients have undergone oophorectomy despite negative imaging, with pathology demonstrating teratoma, and resulting clinical improvement. We present a patient in whom removal of a teratoma, not visible on conventional imaging, resulted in marked clinical improvement. Such cases present a major clinical challenge, needing to consider the risks of oophorectomy, including sterilisation and early menopause, versus the possibility of death in the absence of response to first-line (eg, corticosteroids, plasma exchange, intravenous immunoglobulin), second-line (eg, rituximab) and third-line (eg, bortezomib) immunosuppression. This decision is made more difficult as patients are usually females of childbearing age who at the time lack capacity to make medical decisions. This case also highlights the lack of consensus and guidelines for imaging modalities used to detect teratoma and when to pursue oophorectomy.

中文翻译：

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NMDA 受体脑炎的卵巢切除术和盆腔成像阴性

三分之一患有抗 N-甲基-D-天冬氨酸受体 (NMDAR) 脑炎的女性中发现了卵巢畸胎瘤。当影像学检测到畸胎瘤时，将其切除是一线治疗。即使使用多种成像方式，偶尔也会在随后的成像中发现畸胎瘤，在最初出现很久之后。极少数情况下，尽管影像学阴性，患者仍接受了卵巢切除术，病理学显示畸胎瘤，从而导致临床改善。我们介绍了一位患者，在切除畸胎瘤后，在常规成像上看不到，导致临床显着改善。这些病例是一项重大的临床挑战，需要考虑卵巢切除术的风险，包括绝育和提前绝经，以及对一线治疗（如皮质类固醇、血浆置换、静脉注射免疫球蛋白）、二线（如利妥昔单抗）和三线（如硼替佐米）免疫抑制。这个决定变得更加困难，因为患者通常是育龄女性，当时她们缺乏做出医疗决定的能力。该病例还突出了用于检测畸胎瘤的成像方式以及何时进行卵巢切除术缺乏共识和指南。