Malignant melanoma presenting as a cavernous malformation: systematic literature review and report of 4 illustrative cases

ABSTRACT Objective Intracranial cavernous malformations (CMs) are common, relatively benign neurovascular lesions, whereas malignant melanomas (MMs) of the brain are rare but very aggressive tumors. With nearly identical presentations, CMs and MMs are difficult to distinguish. Despite these similarities, the clinical course and management differ considerably. Methods A systematic review was conducted of all cases of MM presenting as CM, and 4 illustrative cases from a single institution are presented. Clinical and radiological presentation and postoperative outcome data were gathered. Results Eight patients in the literature and 4 patients in the institutional series who fit the inclusion criteria were identified (median range age, 44 7–79 years). All patients presented with radiologically confirmed hemorrhage, 8 with focal neurological deficits, 6 with headaches, 2 with seizures, and 1 with no symptoms. Seven lesions were localized to the brainstem and 5 to the cerebrum. T1-weighted imaging was hyperintense in 9 cases. Five patients had a final diagnosis of primary MM, and 7 patients had metastatic MM. Conclusion Intracranial CMs and MMs are challenging to differentiate before histopathological analysis and are often misdiagnosed on initial presentation. This review emphasizes the importance of considering MM in the differential diagnosis of hemorrhagic intracranial lesions to reduce morbidity and mortality.