Pulmonary Metastasis From Glioblastoma: An Uncommon Clinical Entity

Glioblastoma multiforme (GBM) is an aggressive who grade IV primary brain tumor, yet extracranial metastasis occurs in less than 2% of cases due to the protective effects of the blood-brain barrier and lack of lymphatic drainage. This report describes a 79-year-old woman diagnosed with GBM after resection of a right occipital lesion invading the transverse sinus. Following surgery and radiotherapy, radiological progression was noted seven months later. A PET-CT scan revealed multiple suspicious pulmonary nodules, and further evaluation confirmed right-sided pleural effusion with lymphocytic predominance. Biopsy of a right upper lobe mass demonstrated pulmonary metastasis of glioblastoma, ruling out a second primary lung tumor. The patient required repeated thoracenteses and later pleurodesis, but her condition worsened, leading to death two months after metastasis diagnosis. This case highlights the rarity yet possibility of GBM spreading beyond the central nervous system, especially following neurosurgery or sinus invasion, emphasizing the need for clinical vigilance when systemic symptoms appear.