title: Primary sclerosing epithelioid fibrosarcoma of bone: analysis of a series.
abstract: Sclerosing epithelioid fibrosarcoma (SEF) is a rare, aggressive malignant neoplasm characterized by small nests and linear arrays of epithelioid cells embedded in a dense collagenous matrix. Very few primary SEFs of bone have been reported. Recognition is critical, as the dense extracellular collagenous matrix can be interpreted as osteoid, leading to misdiagnosis as-osteosarcoma. MUC4 and SATB2 are 2 recently characterized immunohistochemical markers for SEF and osteosarcoma, respectively. In reports to date, osteosarcomas are positive for SATB2 and negative for MUC4, whereas soft tissue SEFs have shown the opposite immunohistochemical profile (SATB2-/MUC4+). The purpose of this study was to characterize the clinicopathologic and immunohistochemical features of 8 primary SEFs of bone. The patients presented at a wide range of ages (25 to 73 y; median 52 y). Tumors mostly involved long bones of the extremities, with 3 cases involving the femur, 2 involving the ulna, and 1 involving the humerus. Other sites of involvement included the second rib (1) and the C6 vertebra (1). Follow-up information was available for 7 patients, 3 of whom developed metastases within 2 years of diagnosis. The other 4 patients were free of local recurrence or metastases at 1, 5, 12, and >84 months of follow-up, respectively. Radiographically, the tumors were predominantly lytic and poorly marginated. Histologically, 6 tumors showed pure SEF morphology, and 2 showed hybrid SEF/low-grade fibromyxoid sarcoma morphology. Focal dystrophic mineralization was seen in 1 case but was limited to areas of necrosis. None of the tumors showed the lace-like pattern of mineralization typical of osteosarcoma. The majority (6/8) of the tumors strongly expressed MUC4. SATB2 was negative in all but 1 case, which showed variable weak to moderate staining in ∼50% of nuclei. In general, the combination of morphology, MUC4 expression, and the absence of SATB2 expression was highly useful in arriving at the correct diagnosis.
authors.affiliation: *Department of Pathology, Massachusetts General Hospital ‡Department of Pathology, Brigham and Women's Hospital, Boston, MA †Department of Pathology, University of Iowa, Iowa City, IA.
authors.forename: John B
authors.initials: JB
authors.lastname: Wojcik
authors.forename: Andrew M
authors.initials: AM
authors.lastname: Bellizzi
authors.forename: Paola
authors.initials: P
authors.lastname: Dal Cin
authors.forename: Miriam A
authors.initials: MA
authors.lastname: Bredella
authors.forename: Christopher D M
authors.initials: CD
authors.lastname: Fletcher
authors.forename: Francis J
authors.initials: FJ
authors.lastname: Hornicek
authors.forename: Vikram
authors.initials: V
authors.lastname: Deshpande
authors.forename: Jason L
authors.initials: JL
authors.lastname: Hornick
authors.forename: G Petur
authors.initials: GP
authors.lastname: Nielsen
mesh_terms: D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000032:analysis; D001706:Biopsy; D001859:Bone Neoplasms / Q000737:chemistry / Q000000981:diagnostic imaging / Q000235:genetics / Q000473:pathology* / Q000601:surgery; D003937:Diagnosis, Differential; D015622:Epithelioid Cells / Q000737:chemistry / Q000000981:diagnostic imaging / Q000473:pathology*; D005260:Female; D005354:Fibrosarcoma / Q000737:chemistry / Q000000981:diagnostic imaging / Q000235:genetics / Q000473:pathology* / Q000556:secondary / Q000601:surgery; D006801:Humans; D007150:Immunohistochemistry; D017404:In Situ Hybridization, Fluorescence; D008279:Magnetic Resonance Imaging; D008297:Male; D036961:Matrix Attachment Region Binding Proteins / Q000032:analysis; D008875:Middle Aged; D055264:Mucin-4 / Q000032:analysis; D012516:Osteosarcoma / Q000473:pathology; D011237:Predictive Value of Tests; D012598:Sclerosis; D013997:Time Factors; D014057:Tomography, X-Ray Computed; D014157:Transcription Factors / Q000032:analysis; D016896:Treatment Outcome
chemical_list: D014408:Biomarkers, Tumor; C524658:MUC4 protein, human; D036961:Matrix Attachment Region Binding Proteins; D055264:Mucin-4; C521297:SATB2 protein, human; D014157:Transcription Factors