title: Immunoexpression of ultraviolet photoproducts and p53 mutation analysis in atypical fibroxanthoma and superficial malignant fibrous histiocytoma.
abstract: p53 mutation is one of the major results of ultraviolet (UV) radiation. UV photoproducts of cyclobutane pyrimidine dimers (CPDs) and pyrimidine-pyrimidone (6-4) photoproducts (64PPs) also play an important role in skin cancer development. Atypical fibroxanthoma (AFX), which mimics malignant fibrous histiocytoma (MFH) histologically, occurs in the sun-exposed skin of the elderly, and therefore, an association with UV has long been suspected. Eighteen fibrohistiocytic skin lesions comprising AFX (n = 7), storiform-pleomorphic type MFH centered in the subcutis (superficial MFH; S-MFH; n = 4) and benign fibrous histiocytoma (BFH; n = 7) were used for immunohistochemical and molecular analysis. Eight cases of deep MFH (D-MFH) were also analyzed for UV photoproduct expression for the purposes of comparison. Immunohistochemically, the CPD scores of AFX (3.6 +/- 0.4) were significantly higher than those of S-MFH (1.3 +/- 0.8), D-MFH (0.8 +/- 0.5), or BHF (1.4 +/- 0.7); however, the 64PP scores were extremely low in all these tumors (AFX, 0.1 +/- 0.1; S-MFH, 0.0 +/- 0.0; D-MFH, 0.0 +/- 0.0; and BHF, 0.0 +/- 0.0). AFX, S-MFH, and BFH showed immunoexpression for p53 (2/7, 2/4, and 0/7), respectively. p53 mutations were detected in AFX (4/6; 67%) and S-MFH (1/4; 25%), but not in BFH (0/5; 0%) using polymerase chain reaction-single-strand conformation polymorphism, and all of the mutations in AFX were either C-T transitions or at dipyrimidine sites. In conclusion, AFX and S-MFH are both similar fibrohistocytic lesions; however, AFX has high immunoreactivity for CPDs compared with S-MFH, D-MFH, or BFH. These data suggest that CPDs may play an important role in the pathogenesis of AFX.
authors.affiliation: Department of Anatomic Pathology, Pathological Sciences, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: A
authors.initials: A
authors.lastname: Sakamoto
authors.forename: Y
authors.initials: Y
authors.lastname: Oda
authors.forename: E
authors.initials: E
authors.lastname: Itakura
authors.forename: Y
authors.initials: Y
authors.lastname: Oshiro
authors.forename: O
authors.initials: O
authors.lastname: Nikaido
authors.forename: Y
authors.initials: Y
authors.lastname: Iwamoto
authors.forename: M
authors.initials: M
authors.lastname: Tsuneyoshi
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001483:Base Sequence; D004247:DNA / Q000737:chemistry / Q000235:genetics; D004252:DNA Mutational Analysis; D005260:Female; D018219:Histiocytoma, Benign Fibrous / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D009154:Mutation; D018807:Polymorphism, Single-Stranded Conformational; D011740:Pyrimidine Dimers / Q000032:analysis*; D012878:Skin Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D016159:Tumor Suppressor Protein p53 / Q000235:genetics*
chemical_list: D011740:Pyrimidine Dimers; D016159:Tumor Suppressor Protein p53; D004247:DNA