Anti‐N‐methyl‐d‐aspartate receptor limbic encephalitis associated with mature cystic teratoma of the fallopian tube

Anti‐N‐methyl‐d‐aspartate receptor (NMDAR) limbic encephalitis is the most common form of paraneoplastic encephalitis that is associated with teratomas. Because tumor removal leads to better clinical outcomes, it is essential to reveal the location of the teratomas. This is the first reported case of anti‐NMDAR encephalitis associated with teratoma of the fallopian tube. Salpingo‐oophorectomy improved neurological symptoms and immunohistochemical examinations indicated the expression of NMDAR on neuroglial cells within the fallopian tube teratoma. Teratomas of the fallopian tube cause anti‐NMDAR encephalitis; the imaging analysis and exploratory laparoscopies of the fallopian tube as well as of the ovary should be considered. Surgical removal of both fallopian tubes and ovaries with a normal appearance should be considered for patients in whom immunotherapy is not effective.