Lung carcinoma presenting as metastasis to intracranial meningioma - Case report and review of the literature

Tumor-to-tumor metastasis is rare. The authors report a case of a 52-year-o ld man with a 1-year history of a right parasaggital meningioma, whose clin ical signs were consistent with enlarging meningioma. In preparation for su rgery, the routine preoperative chest radiograph revealed a lung mass. Fine -needle aspiration of the mass revealed adenocarcinoma. The patient underwe nt surgical excision of the intracranial mass, which was thought to be a me ningioma. However, pathologic examination revealed a transitional meningiom a extensively infiltrated with deposits of metastatic carcinoma from the pa tient's primary lung tumor. Metastasis to meningioma was therefore responsi ble for the rapid enlargement of the long-standing meningioma, and caused t he first clinical manifestation of primary lung carcinoma. Recurrent metast asis developed at the surgical site 5 weeks later, requiring surgical excis ion and postoperative radiation to prevent further recurrence. This is a hi ghly unusual presentation for lung carcinoma and, to the authors' best know ledge, is the first such case reported. A review of the published literatur e revealed 20 other cases of lung carcinoma metastatic to meningioma, which were incidentally discovered on surgery or autopsy.