Medulloepithelioma is a rare, primitive, fast-growing brain tumour thought to stem from cells of the embryonic medullary cavity.

[2] A highly malignant undifferentiated primitive neuroepithelial tumour of children, medulloepithelioma may contain bone, cartilage, skeletal muscle, and tends to metastasize extracranially.

[3][4][5][6] Due to rapid growth of the tumour, patients typically present with increased intracranial pressure, seizures, and focal neurologic signs.

[citation needed] Histologically, medulloepithelioma resemble a primitive neural tube and with neuronal, glial and mesenchymal elements.

[citation needed] Medulloepithelioma was originally classified as the most primitive neoplasm of the Central Nervous System (CNS) by Bailey and Cushing in 1926.