Primary Extracranial Meningioma of Mastoid in a Patient With History of Skin Squamous Cell Carcinoma, Lung Adenocarcinoma and Prostatic Carcinoma

Background: Meningiomas are the most common benign intracranial tumors and frequently develop in the parasagittal region, but can also present extracranially. Rarely, meningiomas may involve the middle ear and mastoid, resulting from contiguous spread of adjacent intracranial tumor, or extremely rarely, as an isolated primary tumor, which is frequently misdiagnosed and unrecognized, resulting in inappropriate clinical management. Case Report: Herein we report such a case of an 80-year-old man with history of multiple cancer who presented with ear pain, vertigo and hearing loss. Audiometry demonstrated bilateral sensorineural hearing loss. Contrast-enhanced temporal bone computed tomography revealed a soft-tissue mass in the right epitympanum without bone erosion or any intracranial involvement. Radiological and operative findings were suspicious for cholesteatoma. Histological examination showed an epithelial neoplasm arranged in nests and whorls with intranuclear inclusions. No psammoma bodies, mitotic figures, or tumor necrosis were identified. The tumor cells were positive for epithelial membrane antigen, vimentin, progesterone receptor and CD56; and negative for synaptophysin, chromogranin, pancytokeratin (AE1/AE3), cytokeratin 7, prostate-specificantigen, inhibin, S100, P63, and P40. Ki67 highlighted about 2% of the tumor cells. Based on the morphological features and immunohistochemical profile, the tumor was diagnosed as primary extracranial meningioma of the mastoid, meningothelial subtype, World Health Organization grade 1. Conclusion: To the best of our knowledge, primary mastoid meningioma clinically mimicking a cholesteatoma presenting in a patient with a history of multiple primary carcinomas has not been previously reported. The pathogenesis, diagnosis and treatment of this entity are discussed.