title: Use of alkaline phosphatase staining to differentiate canine osteosarcoma from other vimentin-positive tumors.
abstract: Aspiration of lytic bone lesions is an excellent diagnostic test in the initial evaluation of primary bone neoplasia. However, cytologically, it can be difficult to differentiate osteosarcoma (OSA) from other bone neoplasms, including fibrosarcoma, chondrosarcoma, synovial cell sarcoma, and plasma cell myeloma. The purpose of this study is to determine the sensitivity and specificity of alkaline phosphatase (ALP) staining to differentiate OSA from other tumors that express vimentin by immunocytochemistry or immunohistochemistry. ALP is a hydrolytic enzyme present in multiple tissues including liver, kidney, intestine, placenta, and bone. Hypothetically, neoplasms actively producing bone should be specifically positive for ALP staining. Unstained, cytologic specimens were incubated for 8-10 minutes with nitroblue tetrazolium chloride/5-bromo-4-chloro-3-indolyl phosphate toluidine salt-phosphatase substrate. A positive reaction stains the membrane of the cells gray to black. Samples were counterstained with a Romanowsky's stain to determine whether the sample was of representative cellularity. A total of 61 vimentin-positive neoplasms have been evaluated and confirmed histopathologically. Tumors that expressed vimentin and were positive for ALP included 33 OSAs, one multi-lobular tumor of bone, one amelanotic melanoma, and one chondrosarcoma. Tumors that expressed vimentin and were negative for ALP included chondrosarcomas (three of four), multiple fibrosarcomas, and multiple synovial cell sarcomas. The sensitivity is 100%, and the specificity is 89%. In conclusion, ALP appears to be a highly sensitive and fairly specific marker in the diagnosis of OSA.
authors.affiliation: Department of Venterinary Pathology, College of Veterinary Medicine, University of Illinois, 288 SAC, 1008 Hazelwood Drive, Urbana, IL, USA. abarger@uiuc.edu
authors.forename: A
authors.initials: A
authors.lastname: Barger
authors.forename: R
authors.initials: R
authors.lastname: Graca
authors.forename: K
authors.initials: K
authors.lastname: Bailey
authors.forename: J
authors.initials: J
authors.lastname: Messick
authors.forename: L-P
authors.initials: LP
authors.lastname: de Lorimier
authors.forename: T
authors.initials: T
authors.lastname: Fan
authors.forename: W
authors.initials: W
authors.lastname: Hoffmann
mesh_terms: D000469:Alkaline Phosphatase / Q000032:analysis*; D000818:Animals; D001859:Bone Neoplasms / Q000737:chemistry / Q000175:diagnosis / Q000662:veterinary*; D004396:Coloring Agents; D004283:Dog Diseases / Q000175:diagnosis*; D004285:Dogs; D007150:Immunohistochemistry / Q000662:veterinary; D007211:Indoles; D009580:Nitroblue Tetrazolium; D012516:Osteosarcoma / Q000737:chemistry / Q000175:diagnosis / Q000662:veterinary*; D012680:Sensitivity and Specificity; D013194:Staining and Labeling; D014746:Vimentin / Q000032:analysis*
chemical_list: C501115:5-bromo-4-chloro-3-indolyl phosphate toluidine salt; D004396:Coloring Agents; D007211:Indoles; D014746:Vimentin; D009580:Nitroblue Tetrazolium; D000469:Alkaline Phosphatase