title: Solitary myofibroma of the mandible: an immunohistochemical and ultrastructural study with a review of the literature.
abstract: A solitary myofibroma (MF) is an unusual spindle cell neoplasm that usually arises in the soft tissue, skin, or bone of the head and neck region in infancy. We report an extremely rare case of MF of the mandible in an 18-year-old Japanese woman together with the conventional histologic, immunohistochemical, and electron microscopic findings. The tumor was well circumscribed and composed of fibroblast-like or myofibroblast-like spindle cells. On immunohistochemical evaluation the tumor cells were positive for vimentin, α-smooth muscle actin, HHF-35, and calponin, but negative for neurogenic antigens and markers for vascular endothelial cells. The Ki-67 labeling index was 10 % and the p53 labeling index was 10 %. Ultrastructural examination revealed smooth muscle cell differentiation. The patient was treated by surgical resection and underwent follow-up without any signs of recurrence. MF presents a wide range of differential diagnosis, including benign and malignant neoplasms. Therefore, accurate diagnosis may avoid an unnecessarily aggressive therapy.
authors.affiliation: Department of Oral and Maxillofacial Surgery, Tokyo Medical University, 6-7-1 Nishishinjuku, Shinjuku-ku, Tokyo, 160-0023, Japan, tsatomi@tokyo-med.ac.jp.
authors.forename: Takafumi
authors.initials: T
authors.lastname: Satomi
authors.forename: Michihide
authors.initials: M
authors.lastname: Kohno
authors.forename: Ai
authors.initials: A
authors.lastname: Enomoto
authors.forename: Harutsugu
authors.initials: H
authors.lastname: Abukawa
authors.forename: Ko
authors.initials: K
authors.lastname: Fujikawa
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Koizumi
authors.forename: Daichi
authors.initials: D
authors.lastname: Chikazu
authors.forename: Jun
authors.initials: J
authors.lastname: Matsubayashi
authors.forename: Toshitaka
authors.initials: T
authors.lastname: Nagao
mesh_terms: D000199:Actins / Q000378:metabolism; D000293:Adolescent; D002135:Calcium-Binding Proteins / Q000378:metabolism; D005260:Female; D006652:Histological Techniques; D006801:Humans; D007150:Immunohistochemistry; D019394:Ki-67 Antigen / Q000378:metabolism; D008339:Mandibular Neoplasms / Q000175:diagnosis / Q000601:surgery / Q000648:ultrastructure*; D008840:Microfilament Proteins / Q000378:metabolism; D008854:Microscopy, Electron; D047708:Myofibroma / Q000175:diagnosis / Q000601:surgery / Q000648:ultrastructure*; D014746:Vimentin / Q000378:metabolism; D000096985:Calponins
chemical_list: D000199:Actins; D002135:Calcium-Binding Proteins; D019394:Ki-67 Antigen; D008840:Microfilament Proteins; D014746:Vimentin; D000096985:Calponins