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Case Reports

Abstract

Cutaneous meningioma of the external auditory canal is exceedingly rare, with few isolated case reports and series described in the literature. We report a case of a 65-year-old woman with a long-standing history of progressive right-sided hearing loss and tinnitus, unresponsive to multiple cerumen disimpactions. Otoscopic examination revealed an erythematous, firm lesion obscuring the tympanic membrane and middle ear cleft. The lesion was biopsied. Histologic sections revealed a well-circumscribed neoplasm composed of uniform meningothelial cells with whorled architecture. The tumor cells had indistinct borders, moderate eosinophilic cytoplasm, and oval nuclei with finely dispersed chromatin; occasional intranuclear cytoplasmic pseudoinclusions and rare psammoma bodies were present. There was no necrosis, increased mitotic activity, or significant cytologic atypia. By immunohistochemistry, the tumor cells were diffusely positive for epithelial membrane antigen, somatostatin receptor 2 (SSTR2), progesterone receptor, and vimentin. They were negative for S100, Melan A, and keratin AE1/AE3. While meningiomas are the most common primary brain tumors, they are rarely seen in the skin. Given their rarity, cutaneous meningiomas of the external auditory canal can be misdiagnosed as more common otologic or dermatologic lesions, delaying treatment. As this case may represent a primary cutaneous lesion or secondary extension from an intracranial tumor, comprehensive imaging studies are essential for determining management. This case underscores the need to consider this entity in the differential diagnosis of persistent external auditory canal masses. Prompt biopsy with comprehensive histopathologic and immunohistochemical evaluation is essential to ensure accurate diagnosis and appropriate management.