P0907 - When Agitation, Hallucinations and Paranoia Mean More than Psychosis: The Case of an Ovarian Teratoma.

Introduction: N-methyl-d-aspartate receptor antibody encephalitis (NMDAR-E) is an autoimmune/paraneoplastic syndrome previously recognized as a frequent cause of encephalitis among young individuals and adults, most often in women(1,6). In adults, it commonly presents as a paraneoplastic manifestation of an ovarian teratoma; however, this association is rare in children(1,4). Patients can present with neuropsychiatric signs and symptoms, including memory loss, hallucinations, and decreased level of consciousness(2,3). Diagnosing a paraneoplastic encephalitis may be missed in an adolescent with previous history of depression in the setting of current psychosocial stressors, leading to lethal consequences if untreated(2). NMDAR-E is treatment responsive, and tumor removal and immunotherapy are known to reverse the encephalitis(5).

Case: A 17 year old Hispanic female with a history of depression, anxiety and self-cutting presented with a 2-week history of altered mental status and seizure-like activity. Her mother noted that 4 weeks prior to symptom onset her father was murdered and her grandfather was diagnosed with cancer. Patient reported an “out of body experience,” and developed intermittent episodes of anxiety, giddiness, agitation, left sided paresthesias, decreased appetite, weight loss, auditory and visual hallucinations with paranoid ideation. A week into the disease process, she experienced two seizure-like episodes for which she was hospitalized. On examination, she was afebrile with episodes of disorganized thoughts and visual and auditory hallucinations. Complete blood counts and comprehensive chemistry were normal; urine toxicology screen and pregnancy test were negative. A head CT and brain MRI with contrast were normal. She continued to have waxing and waning agitation, requiring lorazepam, diphenhydramine, haloperidol and physical restraints. She was started on olanzapine with plans to transfer to a psychiatric unit. Cerebrospinal fluid (CSF) evaluation for infectious etiologies, including HSV, were negative. An electroencephalogram was suggestive of encephalopathy. Pulse steroids were initiated for presumed autoimmune encephalitis (AE). The CSF autoimmune/paraneoplastic panel was significant for anti-NMDAR titer of 1:20. Pelvic US and MRI revealed a right ovarian cystic mass (Figure 1A,B). Clinically she developed progressive catatonia, autonomic instability and respiratory depression requiring intubation. An excisional biopsy revealed a mature teratoma (Figure 1C,D), confirming the diagnosis of ovarian teratoma-associated anti-NMDAR-E. Treatment consisted of steroids, plasmapheresis, IVIG and tumor resection, with resolution of clinical and psychiatric symptoms.

Discussion: This case is unique given that the AE was due to an ovarian teratoma-associated paraneoplastic syndrome in a pediatric patient. Teratomas as an etiology for NMDAR-E in adults are well described in close to 50% of cases; however, this association is rare in children(7,1). The patient’s history of depression, anxiety and social stressors initially misled pediatricians to a psychiatric diagnosis. This case highlights the importance of a thorough clinical evaluation in young female patients with new onset neuropsychiatric manifestations and consideration for ovarian teratoma-associated NMDAR-E.