Dural-Based Metastatic Malignant Melanoma Masquerading as Meningiomata: A Diagnostic Challenge

Despite both clinical and radiographic examination, metastases from malignant melanomas can be susceptible to misdiagnoses, particularly when they are found in uncommon locations. We report on an unsettling case of a 38-year-old woman who presented to neurosurgery with worsening neurological symptoms. Upon magnetic resonance imaging, the patient was found to have two sizeable dural-based lesions and underwent subsequent resection of the larger mass. Although the results of the pathohistological examination and immunohistochemistry staining were suspicious for metastatic malignant melanoma, an incorrect diagnosis of atypical meningioma was rendered due to the patient’s age and lack of melanoma history. After the patient’s condition continued to clinically deteriorate, dermatology was ultimately consulted and a more comprehensive work-up was carried out, revealing the correct and exceedingly rare diagnosis of dural-based metastatic melanoma of unknown primary. This case underscores the importance of an interdisciplinary diagnostic approach; one which employs comprehensive histopathologic evaluation, judiciously selected immunohistochemical staining, and thorough physical examination.