title: Gliosarcoma arising in oligodendroglial tumors ("oligosarcoma"): a clinicopathologic study.
abstract: Gliosarcomas are morphologically biphasic tumors composed of glial and sarcomatous elements. Only rare examples of gliosarcoma with oligodendroglial components have been reported. Seven patients with oligodendroglial tumors and a sarcomatous component were identified. Fluorescence in situ hybridization for 1p/19q was sought in glial and sarcomatous regions in all cases. Their mean age at diagnosis of gliosarcoma was 48 years (range 36 to 68) (F:M ratio=5:2). At first resection, the tumors included grade II oligodendroglioma (n=3), grade III oligodendroglioma (n=1), grade II oligoastrocytoma (n=1), and grade III oligoastrocytoma (n=2). The sarcomatous component developed in recurrent/progressive tumors in 6 cases but was a focal finding at first tumor resection in 1 and included fibrosarcoma (n=5), leiomyosarcoma (n=1), or pleomorphic myogenic sarcoma (n=1). Rhabdoid change was a focal finding in the sarcomatous component of 1 tumor. The glial component expressed both glial fibrillary acidic protein and S-100 in all cases, whereas the sarcomatous component at least focally showed smooth muscle actin (n=6), CD34 (n=4), S-100 protein (n=3), and epithelial membrane antigen (n=2) reactivity. Fluorescence in situ hybridization studies demonstrated 1p/19q codeletion in 5 cases, showed no evidence of deletion in 1 case, and technically failed in 1 case. Three of the 5 cases demonstrated 1p/19q codeletion in the sarcomatous component as well. Gliosarcomas with oligodendroglial elements are rare. The relatively frequent presence of 1p/19q codeletion in both glial and sarcomatous components supports the notion that the sarcomatous component represents a metaplastic change occurring in the glial element, the same mechanism active in classic astrocytic gliosarcomas.
authors.affiliation: Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN 55905, USA
authors.forename: Fausto J
authors.initials: FJ
authors.lastname: Rodriguez
authors.forename: Bernd W
authors.initials: BW
authors.lastname: Scheithauer
authors.forename: Robert
authors.initials: R
authors.lastname: Jenkins
authors.forename: Peter C
authors.initials: PC
authors.lastname: Burger
authors.forename: Peter
authors.initials: P
authors.lastname: Rudzinskiy
authors.forename: Euvgeni
authors.initials: E
authors.lastname: Vlodavsky
authors.forename: Adam
authors.initials: A
authors.lastname: Schooley
authors.forename: Joseph
authors.initials: J
authors.lastname: Landolfi
mesh_terms: D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000032:analysis; D001921:Brain / Q000601:surgery; D001932:Brain Neoplasms / Q000737:chemistry / Q000235:genetics / Q000473:pathology* / Q000628:therapy; D002872:Chromosome Deletion; D002878:Chromosomes, Human, Pair 1 / Q000235:genetics; D002888:Chromosomes, Human, Pair 19 / Q000235:genetics; D003131:Combined Modality Therapy; D017809:Fatal Outcome; D005260:Female; D018316:Gliosarcoma / Q000737:chemistry / Q000235:genetics / Q000473:pathology* / Q000628:therapy; D006801:Humans; D007150:Immunohistochemistry; D017404:In Situ Hybridization, Fluorescence; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local; D009367:Neoplasm Staging; D016609:Neoplasms, Second Primary / Q000737:chemistry / Q000473:pathology* / Q000628:therapy; D009837:Oligodendroglioma / Q000737:chemistry / Q000235:genetics / Q000473:pathology* / Q000628:therapy
chemical_list: D014408:Biomarkers, Tumor