Colloid cysts of the third ventricle at post-mortem CT and at autopsy: A report of two cases

• Colloid cysts are slow-growing and histologically benign intracranial tumors.
• Colloid cysts may be asymptomatic or present with symptoms of raised intracranial pressure, caused by intermittent obstruction of the foramen Monroi, which is the opening between the third and lateral ventricles.
• The colloid cysts are clearly visible on CT, even though it is well known that magnetic resonance imaging (MRI) is more suitable for this diagnosis.
• In cases of sudden death of young people with symptoms of high pressure intracranial before death, PMCT or MRI scan would be an opportunity to recognize tumor in the midline and the enlarged ventricular system which will be an indicator for the diagnosis.
• PMCT cannot entirely replace a regular forensic autopsy as it is the combination of radiological, macroscopical and histological findings that result in the correct diagnosis.

Two cases of sudden death due to colloid cysts of the third ventricle are presented. In the first case, a 45-year-old woman suffered from headache. She went to her general practitioner and was referred to a neurologist. After seeing her doctor she went to bed and the next morning her husband found her dead. In the second case, a 20-year-old man with a medical history of intermittent headaches for 5 years was treated by his general practitioner with a drug for migraine for the past 2 years. After a party, he was brought to the hospital unconscious. Acute computed tomography (CT) scan was interpreted as an aneurism bleeding. He incarcerated and died the next day in hospital. In both cases, post-mortem computed tomography (PMCT) revealed a colloid cyst of the third ventricle and hydrocephalus involving the lateral ventricles. These cases demonstrate that fatal cases still occur. Nevertheless, prompt diagnosis CT or magnetic resonance imaging (MRI) is essential, since colloid cysts are histologically benign tumors that can be removed safely by neurosurgical intervention. PMCT scanning can immediately reveal the cysts and a concomitant hydrocephalus is usually easier to demonstrate and document at the CT images than at the autopsy.