Intracranial metastasis from breast cancer is a relatively common finding, however, the appearance of breast cancer metastasis in a meningioma is very rare. Several cases of tumor-to-tumor metastasis and collision tumors have been reported previously, with meningioma being implicated as the most common benign intracranial neoplasm to harbour the metastasis. Occasionally, the discovery of a tumor-to-meningioma metastasis may herald the diagnosis of an occult primary malignancy. Careful histopathological assessment of the resected meningioma specimen is pivotal to the management of these patients, as this will alter the treatment plan and prognosis considerably. Intracranial meningioma with collision breast cancer as primary presentation of an undiagnosed metastatic breast cancer is extremely rare. The current study presents a case of intracranial meningioma with collision breast cancer as a primary presentation, and reviews the available evidence for this unusual disease entity.
Keywords: breast cancer; collision tumor; meningioma; tumor to tumor metastases.