Abstract
INTRODUCTION AND IMPORTANCE: Anti-NMDA receptor encephalitis is a rare autoimmune cause of acute psychosis in young women, often associated with ovarian teratomas. Surgical removal of the teratoma is a critical component of treatment. CASE PRESENTATION: A previously healthy woman was brought to the emergency department with acute psychosis, characterized by alternating episodes of catatonia and mania, regressive speech, and inappropriate behaviors such as disrobing. Despite treatment with antipsychotic medications at a psychiatric facility, her symptoms did not improve, prompting transfer to our institution. Neurological examination was non-focal, and laboratory results were unremarkable. Cerebrospinal fluid analysis showed no signs of infection, but anti-NMDA antibodies were detected. Gynecology was consulted, and a pelvic ultrasound was initially negative. However, pelvic MRI revealed an area of macroscopic fat in the left ovary, suggesting a teratoma. The patient underwent laparoscopic left salpingo-oophorectomy. Gross examination of the ovary appeared normal, but histological analysis confirmed the presence of a benign teratoma with ganglion cells and chronic inflammation. The diagnosis of anti-NMDA receptor encephalitis was confirmed. Postoperatively, the patient's mental status improved significantly, and she was discharged home. CLINICAL DISCUSSION: This case illustrates the clinical, radiologic, and histopathologic features of the disease and underscores the importance of MRI in detecting ovarian teratomas when pelvic ultrasound is inconclusive. CONCLUSION: Timely gynecologic intervention can be curative in these patients.