Intrameningioma Metastasis: Clinical Manifestation of Occult Primary Lung Carcinoma

We report a case of lung carcinoma metastasizing into a meningioma in a 68-year-old female, who presented with progressively worsening right-sided hemiparesis and multiple episodes of adult onset epilepsy. Magnetic resonance imaging revealed an oval-shaped extra-axial hypointense lesion with a central hyperintense nodule in the left frontal region favoring a most probable diagnosis of a meningioma. Left frontoparietal craniotomy and excision of the tumor were carried out and histopathology with hematoxylin and eosin stain revealed a meningioma with metastatic adenocarcinoma and was confirmed by immunohistochemistry. The origin of metastasis was presumed to be from the lungs. A computed tomography (CT) scan of the chest with contrast showed a 3.1 x 2.9 cm mass with spiculated margins in the left lower lobe. Fine needle aspiration cytology (FNAC) proved it to be adenocarcinoma.