A Rare Case of Atypical Pleomorphic Neoplasm of Pineal Region in a Child: A Case Report.

A 10-year-old boy with no past medical history presented with complaints of nausea and vomiting associated with morning headache for the last month. Ophthalmic nerve and eye exam showed diplopia and strabismus with no other significant findings on physical and neurological examination. Magnetic resonance imaging (MRI) of the brain revealed a homogenous hyperdense and enhancing mass in the pineal region. The endoscopic biopsy of the pineal region demonstrated the cells with highly pleomorphic and hyperchromatic nuclei with an increase in mitotic activity. There were many vessels but no area of vascular proliferation and necrosis. Granular bodies with eosinophilia were identified. Immunohistochemistry was positive for class III b-tubulin with epidermal growth factor receptor (EGFR) staining and glial fibrillary acidic protein (GFAP). Immunostaining was positive for p53, Phosphatase and Tensin homolog (PTEN), and oligodendrocyte transcription factor (OLIG2), while staining for cluster of differentiation (CD)34, cytokeratin (CK), human melanoma black (HMB)45, and isocitrate dehydrogenase (IDH)-R132H mutation was negative, consistent with atypical pleomorphic neoplasm of the pineal region. The patient underwent tumor resection via a sub-occipital trans-tentorial approach, followed by one dose of chemotherapy. The patient experienced a resolution of the symptom and was doing well on his bi-monthly follow up.