Schwannoma and Post-vaccine Changes: A Case Report

Schwannomas are benign sheaths of Schwann cells that can present with degenerative and morphological changes; necrosis or hemorrhage are rare findings in these tumors. We present the case of a 28-year-old man with a C2-C4 cervical Schwannoma who experienced upper limb paresthesia in 2020 while presenting with COVID-19 symptoms. The patient later recovered and came to our institution, where surgery was scheduled one year after the initial diagnosis. One week before surgery, the patient received the first dose of the Moderna vaccine. Despite being asymptomatic, the patient underwent successful total resection of the schwannoma, which was confirmed histologically. However, extensive necrosis with abundant foamy macrophages was observed, suggesting a possible link to post-vaccine effects.

Neuro-Behçet With a Thalamic Lesion: A Case Report

Behçet's disease (BD) is an autoimmune disease characterized by multisystemic variable-vessel vasculitis and oral, genital, and intestinal ulcers. Neurological involvement or "Neuro-Behçet" (NB) manifests due to parenchymal inflammation. We present the case of a 21-year-old male with a five-year-old history of intermittent chronic oral and genital ulcers who presented with headache, right hemiparesis, progressive loss of visual acuity, and a thalamic tumor-like lesion on magnetic resonance imaging (MRI). A brain biopsy showed multiple perivascular infarcts associated with vasculitis affecting arterioles, venules, and capillaries.

Steven-Johnson Syndrome Induced by Lamotrigine and Valproic Acid in a Pediatric Patient: A Case Report

Steven-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are part of a spectrum of severe cutaneous adverse reactions, secondary to infections or drug-induced. Although the use of antiseizure medications (ASMs) is a risk factor for the development of SJS/TEN, primary care physicians are not familiar with these cases in some countries. We report a case of SJS associated with ASMs in a nine-year-old girl with a history of difficult-to-control epilepsy, who required adjustment and change in medications.

Anti-N-Methyl-D-Aspartate Receptor Encephalitis With Diffuse Demyelinating Plaques: A Case Report of an Atypical Presentation

Anti-N-methyl-D-aspartate (anti-NMDA) receptor encephalitis is an autoimmune disease triggered by antibodies against the NR1 subunit of this receptor. It has a wide variety of presentations, including abnormal behavior, psychosis, seizures, abnormal movement, insomnia, and irritability. The diagnosis is confirmed by the presence of one of the six main symptoms and anti-NR1 immunoglobulin G (IgG)-positive antibodies in the cerebrospinal fluid (CSF) after the exclusion of other disorders. We present a case of an 18-year-old female with progressive paresthesia and muscle weakness that compromised walking and psychiatric symptoms. She was admitted to a private institution where magnetic resonance imaging (MRI) revealed pseudotumoral lesions, which led to surgical intervention. The original histopathological diagnosis was of a pleomorphic xanthoastrocytoma (PXA) WHO grade 2. As symptoms persisted, she was referred to our institution where a new MRI was performed, and a biopsy was re-evaluated. It showed perivascular inflammatory infiltrates composed of T cells, intense peripheral gliosis, nodules of macrophages, and reactive astrocytes in the white matter with fragmentation and vacuolation of myelin sheets, suggesting a demyelinating process in contrast to neoplasia. CSF analysis was performed, and it was positive for anti-NMDA antibodies. Immunohistochemical positivity for N-methyl-D-aspartate (NMDA) was observed in the neuronal nuclei, which led to the diagnosis.

Subependymal Giant Cell Astrocytoma Non-Associated With Tuberous Sclerosis Complex and Expression of OCT-4 and INI-1: A Case Report

Subependymal giant cell astrocytoma (SEGA) is a rare, slow-growing tumor with a dual (neuroglial) component that is typically associated with tuberous sclerosis complex (TSC). We present the case of a healthy 19-year-old man with mild occipital trauma followed by two weeks of intense headache, with no response to analgesics. Imaging studies revealed a well-defined tumor in the left paraventricular zone. A biopsy showed a SEGA (GFAP+, NF+, nestin+, CK-EA3/EA4+, and TTF1+). TSC was ruled out. An immunohistochemistry (IHC) panel showed aberrant cytoplasmic expression of octamer-binding transcription factor 4 (OCT-4) in endothelial cells, pericytes, and some astrocyte-type cells; integrase interactor 1 (INI-1) expression was observed in the cytoplasm of neoplastic cells; SEGA was not associated with TSC; the expression of nestin and OCT-4 suggested their origin in neuroepithelial stem cells; thyroid transcription factor 1 (TTF-1) expression supported its origin in diencephalic structures. Tuberin expression was decreased. An aberrant pattern of INI-1 was observed, which, together with OCT-4 findings, has not been previously described.