title: Ovarian high-grade serous carcinoma with a noninvasive growth pattern simulating a serous borderline tumor.
abstract: Ovarian serous borderline tumors (SBTs) being a precursor of low-grade serous carcinomas are morphologically characterized by noninvasive growth and low-grade cytology. On the other hand, many pathologists regard cytologically high-grade, noninvasive (HG-noninv) ovarian serous tumors resembling SBTs in low magnification as conventional high-grade serous carcinomas (HGSCs) by personal experiences. Nonetheless, there are no established molecular characteristic of such tumors. In this study, therefore, we attempted to provide the molecular evidence. We selected 37 ovarian serous tumors that exhibited a cytologically HG-noninv growth pattern, including 36 tumors that coexisted with conventional invasive HGSC components (HG-inv) and a single tumor exclusively composed of pure HG-noninv. Histologically, all HG-noninv showed many mitotic figures, and serous tubal intraepithelial carcinomas were identified in 3 tumors with HG-noninv. Immunohistochemically, most HG-noninv showed aberrant p53 expression, frequent IMP3 positivity, p16 overexpression, a high MIB-1 labeling index, and infrequent PAX2. By molecular analysis, the pure HG-noninv and 13 HGSCs with HG-noninv showed TP53 mutations, but KRAS/BRAF mutations were not detected in any of them. In 1 tumor, we detected an identical TP53 mutation in both HG-noninv and HG-inv components by using laser capture microdissection. These immunohistochemical and molecular features of HG-noninv were similar to those of conventional invasive HGSCs but different from those of SBTs. In conclusion, our results showed that a cytologically HG-noninv growth pattern simulating an SBT is a morphological spectrum of HGSC, but not a true SBT.
authors.affiliation: Department of Anatomic Pathology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: Hiroko
authors.initials: H
authors.lastname: Imamura
authors.affiliation: Department of Anatomic Pathology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Ohishi
authors.affiliation: Department of Anatomic Pathology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: Murasaki
authors.initials: M
authors.lastname: Aman
authors.affiliation: Department of Anatomic Pathology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: Kaai
authors.initials: K
authors.lastname: Shida
authors.affiliation: Department of Anatomic Pathology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: Tomoko
authors.initials: T
authors.lastname: Shinozaki
authors.affiliation: Department of Anatomic Pathology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: Nobuko
authors.initials: N
authors.lastname: Yasutake
authors.affiliation: Department of Gynecology and Obstetrics, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: Kenzo
authors.initials: K
authors.lastname: Sonoda
authors.affiliation: Department of Gynecology and Obstetrics, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: Kiyoko
authors.initials: K
authors.lastname: Kato
authors.affiliation: Department of Anatomic Pathology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan. Electronic address: oda@surgpath.med.kyushu-u.ac.jp.
authors.forename: Yoshinao
authors.initials: Y
authors.lastname: Oda
mesh_terms: D014408:Biomarkers, Tumor / Q000032:analysis; D018284:Cystadenocarcinoma, Serous / Q000145:classification / Q000235:genetics / Q000473:pathology*; D018293:Cystadenoma, Serous / Q000145:classification / Q000235:genetics / Q000473:pathology*; D004252:DNA Mutational Analysis; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D061346:Laser Capture Microdissection; D060787:Neoplasm Grading; D010051:Ovarian Neoplasms / Q000145:classification / Q000235:genetics / Q000473:pathology*
chemical_list: D014408:Biomarkers, Tumor
keywords: Noninvasive growth pattern; Nuclear grade; Ovarian high-grade serous carcinoma; Ovarian serous borderline tumor; TP53 mutation