title: Unusual granular cell odontogenic tumor. Report of two undescribed cases with features of granular cell ameloblastoma and plexiform granular cell odontogenic tumor.
abstract: Granular cell ameloblastoma (GCA) is a well recognized variant of follicular ameloblastoma with extensive granular cell change. In contrast, plexiform granular cell odontogenic tumor (PGCOT) is a rare and recently described lesion characterized histologically by a monophasic plexiform pattern of granular cells. In this paper, two cases of an unusual granular cell odontogenic tumor exhibiting combined features of these two entities are described along with their immunohistochemical characteristics. The granular cells of both the GCA and PGCOT areas showed similar patterns of expression for keratin and S-100, which differed from those of typical ameloblastoma. No reactivity for desmin or vimentin was noted. The histomorphologic and immunohistochemical features of these hybrid tumors suggest that the granular cells present have a common origin, most probably the odontogenic epithelium.
authors.affiliation: Department of Oral Pathology, Oral Medicine and Periodontology, Faculty of Dentistry, University of Malaya, Kuala Lumpur, Malaysia.
authors.forename: C H
authors.initials: CH
authors.lastname: Siar
authors.forename: K H
authors.initials: KH
authors.lastname: Ng
mesh_terms: D000328:Adult; D000564:Ameloblastoma / Q000737:chemistry / Q000473:pathology*; D003893:Desmin / Q000032:analysis; D005260:Female; D016586:Granular Cell Tumor / Q000737:chemistry / Q000473:pathology*; D006801:Humans; D007124:Immunoenzyme Techniques; D007150:Immunohistochemistry; D007633:Keratins / Q000032:analysis; D008339:Mandibular Neoplasms / Q000737:chemistry / Q000473:pathology*; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000032:analysis*; D009808:Odontogenic Tumors / Q000737:chemistry / Q000473:pathology*; D009418:S100 Proteins / Q000032:analysis; D014746:Vimentin / Q000032:analysis
chemical_list: D003893:Desmin; D009363:Neoplasm Proteins; D009418:S100 Proteins; D014746:Vimentin; D007633:Keratins