title: Clear cell adenocarcinoma of the tongue.
abstract: A firm, ulcerated tumor formed on the left side of the tongue of an elderly woman. Histopathological analysis showed that this unusual neoplasm was composed of monomorphic polygonal cells that exhibited a clear cytoplasm containing large amounts of periodic acid Schiff (PAS)-positive, diastase-digestive material. Most of the tumor cells stained immunohistochemically for Cytokeratin, high-molecular, CAM5.2, and epithelial membrane antigen (EMA), but were negative for alpha-smooth muscle actin, vimentin, glial fibrillary acid protein (GFAP), and S-100 protein. These findings supported a diagnosis of clear cell adenocarcinoma. Although patients with this type of tumor generally have a favorable prognosis, the tumor in our patient was fast-growing and contained a large number of Ki-67 positive cells, which are known to be highly proliferative. Thus, this case highlights the fact that even clear cell adenocarcinomas that are usually slow-growing should be investigated by conventional morphological techniques and their proliferative activity quantified in order to select the most appropriate treatment strategy.
authors.affiliation: Department of Surgical and Molecular Pathology, Dokkyo University School of Medicine, Shimotsuga, Tochigi, Japan.
authors.forename: Hiromi
authors.initials: H
authors.lastname: Fujita
authors.forename: Masao
authors.initials: M
authors.lastname: Iida
authors.forename: Johji
authors.initials: J
authors.lastname: Imura
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Shinagawa
authors.forename: Fumie
authors.initials: F
authors.lastname: Omotehara
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Kawamata
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Imai
authors.forename: Takahiro
authors.initials: T
authors.lastname: Fujimori
mesh_terms: D018262:Adenocarcinoma, Clear Cell / Q000473:pathology*; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers; D014408:Biomarkers, Tumor / Q000032:analysis; D049109:Cell Proliferation; D003593:Cytoplasm / Q000648:ultrastructure; D017809:Fatal Outcome; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D007633:Keratins / Q000032:analysis; D019394:Ki-67 Antigen / Q000032:analysis; D018396:Mucin-1 / Q000032:analysis; D014062:Tongue Neoplasms / Q000473:pathology*
chemical_list: D015415:Biomarkers; D014408:Biomarkers, Tumor; C400901:CAM 5.2 antigen; D019394:Ki-67 Antigen; D018396:Mucin-1; D007633:Keratins