title: Perineurioma: an unusual cause of an external auditory canal polyp.
abstract: A 33-year-old woman presented with pruritus of the right ear and on examination was found to have 1 x 1 cm polypoid lesion in the external auditory canal. This was removed and histological examination revealed a well-circumscribed spindle cell lesion arranged in fascicles and whorls. Immunohistochemistry showed the tumor to be EMA-positive but S-100-, desmin-, actin-, and cytokeratin-negative. Ultrastructural examination confirmed perineurial cell origin. There are several lesions in which perineurial cells are present, but a true perineurioma is composed exclusively of perineurial cells. It has characteristic morphological, immunohistochemical and ultrastructural features that help separate it from other nerve and neuroectodermal lesions.
authors.affiliation: Department of Anatomical Pathology, University of Natal Medical School, Congella, South Africa. chettyr@med.und.ac.za
authors.forename: R
authors.initials: R
authors.lastname: Donnellan
authors.forename: K
authors.initials: K
authors.lastname: Rughubar
authors.forename: D
authors.initials: D
authors.lastname: Govender
authors.forename: R
authors.initials: R
authors.lastname: Chetty
mesh_terms: D000328:Adult; D002277:Carcinoma / Q000473:pathology* / Q000601:surgery; D003937:Diagnosis, Differential; D004428:Ear Neoplasms / Q000473:pathology* / Q000601:surgery; D004431:Ear, External / Q000473:pathology* / Q000601:surgery; D005260:Female; D006801:Humans; D009378:Neoplasms, Multiple Primary / Q000473:pathology* / Q000601:surgery; D011127:Polyps / Q000473:pathology* / Q000601:surgery