A case report of atypia in angiomatous microcystic meningioma: A mimicker and masker of intratumoral metastasis in a patient with no known systemic malignancy

Abstract

Intratumoral metastasis is rare, and in the brain, meningiomas are the most common type of primary brain tumors to harbor metastases. We report a case of angiomatous microcystic meningioma associated with intratumoral metastatic lung adenocarcinoma in a patient with no prior history of malignancy, in which the pronounced atypia of the meningioma potentially mimics or masks the minute focus of metastatic cancer. A meticulous search for intratumoral metastasis within the meningioma is recommended if metastasis is clinically suspected. A formal ethical approval for the single case report is waived by the Institutional Review Board of National University Health System, Singapore.