title: 'Papillary' solitary fibrous tumor/hemangiopericytoma with nuclear STAT6 expression and NAB2-STAT6 fusion.
abstract: This report describes clinicopathological findings, including genetic data of STAT6, in a solitary fibrous tumor (SFT)/hemangiopericytoma (HPC) of the central nervous system in an 83-year-old woman with a bulge in the left forehead. She noticed it about 5 months before, and it had grown rapidly for the past 1 month. Neuroradiological studies disclosed a well-demarcated tumor that accompanied the destruction of the skull. The excised tumor showed a prominent papillary structure, where atypical cells were compactly arranged along the fibrovascular core ('pseudopapillary'). There was rich vasculature, some of which resembled 'staghorn' vessels. Mitotic figures were occasionally found. Whorls, psammoma bodies, or intra-nuclear pseudoinclusions were not identified. By immunohistochemistry, CD34 was strongly positive in the tumor cells, and STAT6 was localized in their nuclei. By reverse transcription-polymerase chain reaction (RT-PCR), an NAB2-STAT6 fusion gene, NAB2 exon6-STAT6 exon17, was detected, establishing a definite diagnosis of SFT/HPC. 'Papillary' SFT/HPC needs to be recognized as a possible morphological variant of SFT/HPC, and should be borne in mind in its diagnostic practice.
authors.affiliation: Department of Pathology, Saitama Medical University, 38 Morohongo, Moroyama-town, Iruma-gun, Saitama, 350-0495, Japan. ishizawa@saitama-med.ac.jp.
authors.forename: Keisuke
authors.initials: K
authors.lastname: Ishizawa
authors.affiliation: Department of Surgical Pathology, Hyogo College of Medicine, 1-1 Mukogawa-cho, Nishinomiya, Hyogo, 663-8501, Japan.
authors.forename: Yoshitane
authors.initials: Y
authors.lastname: Tsukamoto
authors.affiliation: Department of Neurosurgery, Saitama Medical University International Medical Center, 1397-1 Yamane, Hidaka, Saitama, 350-1298, Japan.
authors.forename: Shunsuke
authors.initials: S
authors.lastname: Ikeda
authors.affiliation: Department of Neurosurgery, Saitama Medical University International Medical Center, 1397-1 Yamane, Hidaka, Saitama, 350-1298, Japan.
authors.forename: Tomonari
authors.initials: T
authors.lastname: Suzuki
authors.affiliation: Department of Pathology, Saitama Medical University, 38 Morohongo, Moroyama-town, Iruma-gun, Saitama, 350-0495, Japan.
authors.forename: Taku
authors.initials: T
authors.lastname: Homma
authors.affiliation: Department of Neurosurgery, Saitama Medical University International Medical Center, 1397-1 Yamane, Hidaka, Saitama, 350-1298, Japan.
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Mishima
authors.affiliation: Department of Neurosurgery, Saitama Medical University International Medical Center, 1397-1 Yamane, Hidaka, Saitama, 350-1298, Japan.
authors.forename: Ryo
authors.initials: R
authors.lastname: Nishikawa
authors.affiliation: Department of Pathology, Saitama Medical University, 38 Morohongo, Moroyama-town, Iruma-gun, Saitama, 350-0495, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Sasaki
mesh_terms: D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000235:genetics* / Q000378:metabolism*; D001932:Brain Neoplasms / Q000098:blood supply / Q000175:diagnosis / Q000235:genetics* / Q000473:pathology; D005260:Female; D015870:Gene Expression / Q000235:genetics*; D050939:Gene Fusion / Q000235:genetics*; D006393:Hemangiopericytoma / Q000098:blood supply / Q000175:diagnosis / Q000235:genetics* / Q000473:pathology; D006801:Humans; D007150:Immunohistochemistry; D008279:Magnetic Resonance Imaging; D009378:Neoplasms, Multiple Primary / Q000235:genetics* / Q000473:pathology; D059906:Neuroimaging; D012097:Repressor Proteins / Q000235:genetics* / Q000378:metabolism*; D050800:STAT6 Transcription Factor / Q000235:genetics* / Q000378:metabolism*; D054364:Solitary Fibrous Tumors / Q000098:blood supply / Q000175:diagnosis / Q000235:genetics* / Q000473:pathology; D014057:Tomography, X-Ray Computed
chemical_list: D014408:Biomarkers, Tumor; C491000:NAB2 protein, human; D012097:Repressor Proteins; D050800:STAT6 Transcription Factor; C494101:STAT6 protein, human
keywords: Hemangiopericytoma; NAB2-STAT6 fusion; Papillary structure; STAT6-immunohistochemistry; Solitary fibrous tumor