Unusual growth within a meningioma (leukemic infiltrate)

Intracranial meningiomas are generally slow-growing neoplasms. Symptoms depend on their critical intracranial location. The authors describe a case of rapidly enlarging meningioma that became symptomatic as a result of invasion by leukemic cells at the time of a blastic crisis in the context of chronic myeloid leukemia. Infiltration of an intracranial meningioma by cells from extracranial malignant neoplasms is a rare event. Even though central nervous system (CNS) or meningeal involvement is common in some hematologic malignancies, this is, to the best of our knowledge, the first report of invasion of an intracranial meningioma by leukemic cells.