Distinguishing mimics from true hemorrhagic cavernous malformations

Area of Science:

• Neurology
• Radiology
• Oncology

Background:

• Cavernous malformations (CM) are vascular malformations often identified by characteristic MRI signals.
• Distinguishing CMs from hemorrhagic tumors can be challenging due to overlapping imaging features.
• Tumors can present as mimics of CMs, necessitating careful diagnostic evaluation.

Purpose of the Study:

• To compare clinical and radiological features of tumors mimicking CMs against true brain cavernous malformations.
• To identify key factors that can help differentiate between CM mimics and genuine hemorrhagic CMs.
• To establish criteria for suspecting CM mimics in diagnostic imaging.

Main Methods:

• Retrospective comparison of 5 tumor mimic cases with 51 sporadic hemorrhagic CM cases.
• Analysis of clinical data, initial diagnostic MRI, and follow-up MRI evolution (<1 year).
• Statistical comparison of patient demographics, medical history, and radiological findings.

Main Results:

• Tumor mimic patients were older and more likely to have a history of neoplasm compared to true CM patients.
• Mimics showed higher rates of lesion enhancement on initial MRI and persistent edema on follow-up MRI.
• CM mimics exhibited distinct MRI evolution patterns, including mixed diffusion-weighted imaging signals and less frequent progression to advanced lesion types.

Conclusions:

• Clinical and radiological features, including age, prior neoplasm history, and specific MRI findings, can help distinguish tumor metastases from true hemorrhagic CMs.
• Suspicion for CM mimics is warranted in older patients with a history of cancer and contrast enhancement on MRI.
• Follow-up MRI within 90 days is recommended to confirm CM diagnosis, with persistent edema and enhancement suggesting a tumor.