Isolated parenchymal cysts associated with a secretory meningioma: illustrative case

BACKGROUND: Meningiomas represent one of the most common intracranial tumors found in adults. Uncommonly, these tumors can be associated with an adjacent cyst, which is in direct contact with the tumor. Tumor location and source have previously been categorized into five subtypes. OBSERVATIONS: This report details the novel findings of a secretory meningioma with associated cysts separated from the tumor by brain parenchyma. Histopathological analysis of the cyst wall showed no evidence of neoplasia, suggesting the etiology to be from the parenchymal edema. LESSONS: The authors suggest that the presence of isolated cysts in conjunction with a meningioma (in this case a secretory meningioma) represents a new type VI cyst. These cysts are nonneoplastic and do not require direct operative access for control but can be managed, if needed, with simple aspiration. https://thejns.org/doi/10.3171/CASE25964.