title: Comparative ultrastructural and immunohistochemical study of perineurioma and neurofibroma of the oral mucosa.
abstract: In the course of assessing the cellular composition of intraoral neurofibroma (NF), we encountered a unique gingival tumor of putative perineurial (PN) origin. The lesion showed the ordinary light microscopic NF pattern, but the ultrastructural features of well-differentiated PN cells as well as an epithelial membrane antigen (EMA)-positive, S-100 protein-negative immunoprofile confirmed the diagnosis of soft tissue perineurioma (STP). In our small series of NF, there were three ultrastructural subtypes: Type I (common Schwann cell type), Type II (NF with a high content of PN cells) and Type III (predominantly fibroblastic NF), although inhomogeneous and overlapping assembly of cellular elements. A significant number of tumor cells in Type II showed the substantial reactivity for EMA, whereas many CD34-positive cells were noted in Type III. The present results confirm previous findings that PN lineage is an important constituent in the formation of NF and reinforce the value of electron microscopy in the diagnosis of peripheral nerve sheath tumors.
authors.affiliation: Department of Oral Pathology, Meikai University School of Dentistry, 1-1 Keyakidai, Sakado, Saitama 350-0283, Japan. idef@dent.meikai.ac.ip
authors.forename: Fumio
authors.initials: F
authors.lastname: Ide
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Shimoyama
authors.forename: Norio
authors.initials: N
authors.lastname: Horie
authors.forename: Kaoru
authors.initials: K
authors.lastname: Kusama
mesh_terms: D014408:Biomarkers, Tumor / Q000378:metabolism; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008854:Microscopy, Electron; D008875:Middle Aged; D009062:Mouth Neoplasms / Q000175:diagnosis / Q000378:metabolism / Q000648:ultrastructure*; D009363:Neoplasm Proteins / Q000378:metabolism; D018317:Nerve Sheath Neoplasms / Q000175:diagnosis / Q000378:metabolism / Q000648:ultrastructure*; D009455:Neurofibroma / Q000175:diagnosis / Q000378:metabolism / Q000648:ultrastructure; D009418:S100 Proteins / Q000378:metabolism
chemical_list: D014408:Biomarkers, Tumor; D009363:Neoplasm Proteins; D009418:S100 Proteins