Meningeal Hamartoma Of The Middle Ear, A Challenging Case In Frozen Section

Introduction:Meningiomas are one of the most frequent neoplasms of the central nervous system. On theother hand, extra-cranial (ectopic) meningiomas have been reported in various anatomicalsites, however, their occurrence is considered low.Case presentation:A 49-year-old woman presented with pain and mixed unilateral hearing loss in the left ear.Initial diagnosis based on the first biopsy was mostly compatible with otic polyp (auralpolyp), despite the fact that all of the clinical features were not seen in the patient.HRCT of the left temporal bones showed opacification of the left mastoid which extended tothe left external acoustic meatus. A radical surgery performed for the patient and frozensection duringsurgery reported as squamous cell carcinoma.Histologic examination of permanent sections indicated anastomosing and dilated spacesresembling vascular channels associated with dense fibrous tissue. Which were covered andlined by small and round eosinophilic epithelioid cells. Some cells gathered together andformed small cell sheets. The cells had minimal or no atypia and showing no mitotic activityand intranuclear inclusion bodies were seen between them. Panel for immunohistochemistry(IHC), usingpan-cytokeratin (CK), S-100, P63, carcinoembryonic antigen (CEA) andepithelial membrane antigen (EMA) was done which all of them except EMA were negative.So, the best match was ectopic meningothelial hamartoma or extracranial meningioma.Discussion:Whereas ectopic meningioma is assumed extremely rare, it can pose a diagnostic challengespecifically in fresh specimens like frozen sections and fine needle aspiration (FNA). Since,symptoms and radiological data are not specific, it is wise to perform an appropriate biopsyand consider histological features and immunohistochemistry analysis before definitetreatment. Also a radiological evaluation before the surgery is necessary to rule out theintracranial meningioma.

کلیدواژه ها:

meningioma ، middle ear ، extra cranial