title: Galectin-1 (GAL-1) expression is a useful tool to differentiate between small cell osteosarcoma and Ewing sarcoma.
abstract: Galectin-1 (GAL-1) is frequently expressed in osteosarcomas. Although a valuable diagnostic marker to differentiate between chondroblastic osteosarcomas and conventional chondrosarcomas, it has not been tested in the Ewing sarcoma family of tumors (ESFTs). We studied by immunohistochemistry GAL-1 expression in 43 osteosarcomas, 23 chondrosarcomas, and 217 genetically confirmed ESFTs using a tissue microarray. GAL-1 was expressed in 78 % of osteosarcomas, 33 % of chondrosarcomas, and 8 % of ESFTs. Osteoblastic and small cell osteosarcoma subtypes expressed GAL-1 in a high percentage of cells when compared with the other histological subtypes, whereas two chondroblastic osteosarcomas were negative. GAL-1 was mainly expressed in high-grade chondrosarcomas (grade III). ESFTs were rarely positive (8 %), and this was not related to the histological subtype nor to the clinical outcome. Although GAL-1 expression distinguishes chondroblastic osteosarcomas from conventional chondrosarcomas and is usually negative in conventional chondrosarcomas, the final diagnosis needs to incorporate histopathology since some chondroblastic osteosarcomas fail to express GAL-1, while high-grade chondrosarcomas are GAL-1 positive. Since GAL-1 is frequently expressed in osteogenic tumors, including small cell osteosarcoma, but rarely positive in ESFTs, its expression seems a valuable tool for distinguishing between these lesions. GAL-1 immunoexpression is not indicative of prognosis in ESFT.
authors.affiliation: Department of Pathology, Instituto Valenciano de Oncología, Valencia, Spain.
authors.forename: Isidro
authors.initials: I
authors.lastname: Machado
authors.forename: José Antonio
authors.initials: JA
authors.lastname: López Guerrero
authors.forename: Samuel
authors.initials: S
authors.lastname: Navarro
authors.forename: Empar
authors.initials: E
authors.lastname: Mayordomo
authors.forename: Katia
authors.initials: K
authors.lastname: Scotlandi
authors.forename: Piero
authors.initials: P
authors.lastname: Picci
authors.forename: Antonio
authors.initials: A
authors.lastname: Llombart-Bosch
mesh_terms: D014408:Biomarkers, Tumor / Q000378:metabolism*; D001859:Bone Neoplasms / Q000175:diagnosis* / Q000378:metabolism; D002452:Cell Count; D002804:Chondroblastoma / Q000175:diagnosis / Q000378:metabolism; D002813:Chondrosarcoma / Q000175:diagnosis / Q000378:metabolism; D003937:Diagnosis, Differential; D037483:Galectin 1 / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D011379:Prognosis; D012189:Retrospective Studies; D012512:Sarcoma, Ewing / Q000175:diagnosis* / Q000378:metabolism; D018228:Sarcoma, Small Cell / Q000175:diagnosis* / Q000378:metabolism
chemical_list: D014408:Biomarkers, Tumor; D037483:Galectin 1; C445499:LGALS1 protein, human