Diagnosis and management of multifocal gliomas

Patients who present with multiple cerebral tumors are usually considered as having metastatic disease. If they have a history of a primary cancer in another site, the brain tumors are considered metastases and are usually managed with standard whole-brain radiotherapy. If no primary cancer site is known, a diagnostic work-up is performed, but if no primary site is found, they are still considered as brain metastases from an unknown primary site. Thus, such patients can either have brain biopsy (recommended) for further diagnostic consideration or, occasionally, they can be treated with whole-brain radiotherapy, depending on the age, performance status and wish of the patient. However, in some of these patients the multiple brain tumors represent multifocal glioma rather than metastases, resulting in incorrect treatment. In such cases, various MRI characteristics may be helpful in directing towards the correct diagnosis. Thus, patients who present with multiple brain tumors should not always be considered to have metastatic disease even if they have a previous diagnosis of systemic cancer, and multifocal glioma should be ruled out.