Summary

A 72-year-old man was brought to the emergency department with acute onset confusion and haemoptysis. Chest X-ray showed a possible lung mass, while CT head showed a fluid-filled, space-occupying lesion (SOL) in the right frontal lobe of the brain. MRI head indicated that this SOL had spilt its contents into the subarachnoid and intraventricular spaces. Due to a fluctuating Glasgow Coma Scale (GCS), the patient underwent emergency debulking. Macroscopically, a frail-walled cystic tumour filled with straw-coloured fluid was noted; histology confirmed metastasis from a primary lung adenocarcinoma. Whole brain radiotherapy was given, with a view to commence systemic therapy. The patient, however, deteriorated and unfortunately passed away a few weeks after completing radiotherapy. This patient presented with leptomeningeal metastasis as the first presentation of a lung adenocarcinoma, and had a highly unusual mechanism by which leptomeningeal spread had occurred, with metastatic brain tumour spilling its contents into the meningeal spaces.