Fatal colloid cyst of the foramen of Monro: A forensic case report

We describes of a 58-year-old Indian man who died within 2 hours of becoming unconscious, with no prior symptoms. Brain non-contrast computed tomography (NCCT) imaging of the head revealed a round hyperdense mass measuring about 2 cm in diameter present in the foramen of Monro of the third ventricle of the brain, with marked dilatation of the lateral and third ventricles and brain oedema. Post-mortem examination, revealed a greenish-grey shining firm to hard mass in the foramen of Monro of the third ventricle, with marked dilatation of the lateral and third ventricles and brain oedema with brain herniation. On cut section, the lumen contained gelatinous material. Histopathology confirmed the mass as a colloid cyst. The cyst was centrally filled with dense eosinophilic colloid-like material containing numerous elongated cholesterol clefts and was externally covered by a thin hypocellular fibrous wall and lined by ciliated cuboidal epithelium.