Paraneoplastic Encephalitis Triggered by a Dermoid Cyst in 19-Year-Old Female,
Case Report

Authers: Asmaa.Ghannam , Mohammad.Al Morr , Mashhour.Naasan, Raghad. Qashoo, Loai,Massad, Almotazbellah.Zeer . 1,2 2 3 2 2 2
Affiliations:(1)Razan Center for Infertility, Palestine , (2) Ibn Sina Specialized Hospital, Jenin, Palestine, (3) Arab Hospitals Group, Palestine.Email: asmaa.ghannam@ish.ps

Introduction:
Autoimmune encephalitis (AE) is an inflammatory condition of the central nervous system (CNS) associated
with specific antibodies targeting neuronal or synaptic proteins, anti N-methyl-D-aspartic acid (NMDA)
receptor. This report presents a rare case of (AE) presented with seizures, cognitive and behavioral changes,
found to be associated with the presence of a Dermoid cyst, emphasizing the significance of timely diagnosis
and management.

Case description:
A19-year-old female presented to emergency department with status epilepticus, admitted to ICU for
stabilization.
Previous behavioral changes, confusion, memory deficits for the preceding two weeks,
Neurologic exam: Disoriented, with impaired short-term memory and occasional episodes of agitation. No
focal deficits.
Investigation:
Routine lab, brain CT, EEG, CSF analysis & gram stain, bacterial and viral PCR all were unremarkable.
Brain MRI : limbic encephalitis.
CSF analysis positive for Anti-NMDA antibodies.
Pelvic MRI: small left ovarian mass 3.5x3 cm mostly teratoma. (Figure1)
Managment:
Initially: empirical antibiotics, antivirals, anti-epileptics and antipsychotics to treat symptoms.
Steroid pulse therapy, plasmapheresis, IVIG and monoclonal antibodies (Rituximab).
laparoscopic ovarian cystectomy, (Figure 2). Histopathology: mature teratoma with presence of glial tissue.
Outcome:
Significant improvement in neurologic and psychiatric symptoms within two weeks post-surgery.
Complications of long ICU stay (sepsis, acute kidney injury, venous thromboembolism),
Rehabilitation: motor, language, cognitive and behavioral therapy
At six-month follow-up, she had no recurrence of symptoms and resumed normal activities.

Discussion:
This case highlights the rare association between (AE) and a
Dermoid cyst which can induce an autoimmune response due to
the presence of ectodermal derivatives, including neural tissue.
The estimated annual incidence of Anti-NMDA encephalitis ~1.5
cases per million persons.1
The diagnostic process for (AE) presents significant challenges
attributed to the overlapping clinical features with other
neurological and psychiatric disorders, complicating timely
identification and treatment.2
Early diagnosis and resection of the underlying tumor are critical
for preventing further immune-mediated neuronal damage. 3

Conclusion:
Dermoid cysts should be considered in the differential diagnosis
of (AE), especially in young females with no other apparent
etiology. Early recognition, immunotherapy, and tumor removal
can lead to favorable outcomes.

References
1.Dubey D, Pittock SJ, Kelly CR, et al. Autoimmune encephalitis epidemiology and a comparison to infectious encephalitis. Ann Neurol 2018; 83: 166-177.
2. Graus F, Titulaer MJ, Balu R, et al. A clinical approach to diagnosis of autoimmune encephalitis. Lancet Neurol 2016; 15: 391-404.
3.Dalmau J, Armangue T, Planaguma J, et al. An update on anti-NMDA receptor encephalitis for neurologists and psychiatrists: mechanisms and models.
Lancet Neurol 2019; 18: 1045-1057.