title: Overexpression of MDM2 in a sclerosing epithelioid fibrosarcoma: genetic, immunohistochemical and ultrastructural study of a case.
abstract: Sclerosing epithelioid fibrosarcoma (SEF) is an extremely rare soft-tissue neoplasm. Here, we describe the molecular genetic alterations and histological, immunohistochemical and ultrastructural features of a primary SEF arising in the retroperitoneum. The tumor consisted of uniform small round to ovoid epithelioid cells, arranged in nests and cords and surrounded by a prominent hyalinized collagenous matrix. The tumor cells expressed only vimentin. Ultrastructurally, the tumor cells showed features of fibroblasts, with an abundant rough endoplasmic reticulum in the cytoplasm. Neither p53 gene mutations nor p53 protein overexpression were detected, but more than 70% of all tumor cells showed strong immunoreactivity with murine double minute 2 (MDM2). Our results suggest that MDM2 overexpression is likely to play a role in tumorigenesis in this lesion in p53-dependent or p53-independent pathways. To our knowledge, the present study is the first molecular genetic study of this rare lesion. Further studies will be necessary to clarify the molecular basis of tumorigenesis of this rare lesion.
authors.affiliation: Division of Pathology, Central Clinical Laboratory, School of Medicine, Iwate Medical University, Morioka, Japan.
authors.forename: Yu-Fei
authors.initials: YF
authors.lastname: Jiao
authors.forename: Shin-ichi
authors.initials: S
authors.lastname: Nakamura
authors.forename: Tamotsu
authors.initials: T
authors.lastname: Sugai
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Uesugi
authors.forename: Wataru
authors.initials: W
authors.lastname: Habano
authors.forename: Masaya
authors.initials: M
authors.lastname: Ogata
authors.forename: Tomoaki
authors.initials: T
authors.lastname: Fujioka
mesh_terms: D000368:Aged; D004252:DNA Mutational Analysis; D015622:Epithelioid Cells / Q000737:chemistry / Q000473:pathology* / Q000648:ultrastructure; D005260:Female; D005354:Fibrosarcoma / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D006801:Humans; D007150:Immunohistochemistry; D008854:Microscopy, Electron; D009687:Nuclear Proteins; D018807:Polymorphism, Single-Stranded Conformational; D011518:Proto-Oncogene Proteins / Q000096:biosynthesis*; D051736:Proto-Oncogene Proteins c-mdm2; D012598:Sclerosis; D016159:Tumor Suppressor Protein p53 / Q000235:genetics
chemical_list: D009687:Nuclear Proteins; D011518:Proto-Oncogene Proteins; D016159:Tumor Suppressor Protein p53; C497206:MDM2 protein, human; D051736:Proto-Oncogene Proteins c-mdm2