Occult teratoma in a case of N-methyl-D-aspartate receptor encephalitis

Abstract

N-methyl-D-aspartate receptor encephalitis (NMDARe) is one of 13 autoimmune-mediated encephalitides that have been discovered over the last decade. This case report describes the course of a 26-year-old female who presented with new-onset seizures and insomnia, complicated by encephalitis. The initial workup ruled out common causes of encephalitis, while a transvaginal ultrasound (TVUS), and computed tomography (CT) scans of the chest, abdomen, and pelvis did not identify a mass. Based on the suspicion that she may have autoimmune encephalitis, the patient was treated with intravenous immunoglobulins and plasma exchange, but continued to deteriorate. Whole-body positron emission tomography (PET) scan identified a small hypermetabolic pelvic mass. Shortly thereafter serum and cerebral spinal fluid NMDAR antibody titers were reported as positive, prompting repetition of the TVUS, which confirmed the presence of an ovarian teratoma. The patient had a laparoscopic oophorectomy with subsequent resolution of her symptoms, further confirming the diagnosis. Despite the sensitivities of TVUS and CT of up to 94% and 98%, respectively, the teratoma was unusually small, necessitating the addition of a PET scan to identify the lesion. These neoplasms are thought to have low uptake on PET; however, it is possible that focal inflammation may have enhanced the detection. It is unlikely that the teratoma grew during hospitalization as the average growth rate is 1.8 mm per year. Regardless, the lesson that can be learned is that imaging modalities beyond CT and TVUS, such as PET, can be helpful, as identification of a resectable tumor may alter management and ultimately improve outcomes.

Brain anomalies in early psychosis: From secondary to primary psychosis

“…This was found to be the case: (i) in autoimmune or inflammatory diseases, as reported in the many cases of anti-NMDAR encephalitis, requiring immunosuppressive therapy and surgery of ovarian teratomas (Sabbula et al 2020;Lwanga et al 2018), or in multiple sclerosis and neurolupus, where psychosis also remitted after immunosuppressive therapy (Jghaimi, Kabbaj, and Essaadouni 2009;Jongen 2006); (ii) in tumoral processes where surgical resection led to full remission in the case of an epidermoid cyst in the pineal gland or a hypothalamic hamartoma (Jiang et al 2018;Al-Hail et al 2010), or clear improvement in a grade II meningioma (Gama Marques 2020), and in morphologic anomalies like arachnoid cysts, where the treatment of the subsequent intracranial pressure could also bring full recovery; finally, (iii) in metabolic disorders such as 5,10-methylenetetrahydrofolate reductase deficiency or Niemann-Pick type C, where adequate supplementation achieved full recovery (Iida et al 2017;Walterfang 2006).…”

Reporte de un caso fatal de encefalitis autoinmunitaria asociada a teratoma ovárico

“…En la última década se han descrito aproximadamente 13 encefalitis de origen autoinmunitario, una de las cuales es la causada por anticuerpos contra los receptores NMDA 12 . El primer reporte de caso que hace alusión a esta afección data de 1997, en una mujer joven con un cuadro de encefalitis límbica y un teratoma ovárico asociado 13 .…”

Bortezomib for the treatment of refractory anti‐N‐methyl‐d‐aspartate receptor encephalitis

“…Prophylactic left oophorectomy was also performed after considering case reports of anti-NMDAR encephalitis with normal-appearing ovaries, in which bilateral salpingo-oophorectomy showed benefit. 2,3 She remained intubated and had continuous oro-lingual-facial dyskinesias and rhythmic dystonic upper limb posturing. Electroencephalogram demonstrated generalised delta activity with extreme 'delta brush' pattern.…”