The Experts below are selected from a list of 288 Experts worldwide ranked by ideXlab platform
Osamu Matsubara - One of the best experts on this subject based on the ideXlab platform.
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Loss of ARID1A protein expression occurs as an early event in ovarian clear-cell carcinoma development and frequently coexists with PIK3CA mutations
Modern Pathology, 2012Co-Authors: Sohei Yamamoto, Hitoshi Tsuda, Masashi Takano, Seiichi Tamai, Osamu MatsubaraAbstract:ARID1A is a recently identified tumor suppressor gene that is mutated in ∼50% of ovarian clear-cell carcinomas. This mutation is associated with loss of ARID1A protein expression as assessed by immunohistochemistry. The present study aimed at determining the timing of the loss of ARID1A protein expression during the development of ovarian clear-cell carcinoma and assessing its relevance in correlation to PIK3CA gene mutations. A total of 42 clear-cell carcinoma cases with adjacent putative precursor lesions (endometriosis-associated carcinoma cases ( n =28) and (clear-cell) Adenofibroma-associated carcinoma cases ( n =14)) were selected and subjected to immunohistochemical analysis for ARID1A protein expression and direct genomic DNA sequencing of exons 9 and 20 of the PIK3CA gene. ARID1A immunoreactivity was deficient in 17 (61%) of the 28 endometriosis-associated carcinomas and 6 (43%) of the 14 Adenofibroma-associated carcinomas. Among the precursor lesions adjacent to the 23 ARID1A-deficient carcinomas, 86% of the non-atypical endometriosis (12 of 14) and 100% of the atypical endometriosis (14 of 14), benign (3 of 3), and borderline (6 of 6) clear-cell Adenofibroma components were found to be ARID1A deficient. In contrast, in the 19 patients with ARID1A-intact carcinomas, all of the adjacent precursor lesions retained ARID1A expression regardless of their types and cytological atypia. Analysis of 22 solitary endometrioses and 10 endometrioses distant from ARID1A-deficient carcinomas showed that all of these lesions were diffusely immunoreactive for ARID1A. Among the 42 clear-cell carcinomas, somatic mutations of PIK3CA were detected in 17 (40%) tumors and majority (71%) of these were ARID1A-deficient carcinomas. These results suggest that loss of ARID1A protein expression occurs as a very early event in ovarian clear-cell carcinoma development, similar to the pattern of PIK3CA mutation recently reported by our group, and frequently coexists (not mutually exclusive) with PIK3CA mutations.
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Expression of platelet-derived growth factors and their receptors in ovarian clear-cell carcinoma and its putative precursors
Modern Pathology, 2008Co-Authors: Sohei Yamamoto, Hitoshi Tsuda, Masashi Takano, Tsunekazu Kita, Kazuya Kudoh, Kenichi Furuya, Seiichi Tamai, Osamu MatsubaraAbstract:Recent studies have shown that platelet-derived growth factors and their receptors are frequently co-expressed in ovarian cancers. Herein, we investigated the role of the platelet-derived growth factor pathway in the development of ovarian clear-cell adenocarcinoma, a highly chemoresistant form of ovarian cancer. Immunohistochemical expression of platelet-derived growth factor receptor- α and receptor- β , platelet-derived growth factor A-chain and B-chain was examined in 31 cases of clear-cell adenocarcinoma and 56 coexisting putative precursor lesions: 17 non-atypical and 19 atypical endometrioses, and 10 non-atypical and 10 atypical clear-cell Adenofibroma components. Twenty-one solitary endometrioses were also examined. Vascular endothelial cells were always positive for all the markers examined, and were used as positive controls. The frequencies of positivity for platelet-derived growth factor receptor- α and receptor- β , and platelet-derived growth factor A-chain increased in accordance with higher cytologic atypia in the putative precursors: 71, 47, and 59% in the 17 non-atypical endometrioses, 84, 73, and 84% in the 19 atypical endometrioses, 0% each in the 10 non-atypical clear-cell Adenofibromas, 100, 90, and 90% in the 10 atypical clear-cell Adenofibromas, and 97, 97, and 100% in the 31 clear-cell adenocarcinomas, respectively. Positivity for platelet-derived growth factor B-chain increased in accordance with increased atypia in clear-cell Adenofibroma: 0% in non-atypical clear-cell Adenofibromas, 30% in atypical clear-cell Adenofibromas, and 60% in coexisting carcinomas. However, in contrast, positivity for platelet-derived growth factor B-chain decreased in accordance with increased atypia in endometriosis coexisting with clear-cell adenocarcinomas: 35% in non-atypical endometrioses, 11% in atypical endometrioses, and 5% in coexisting carcinomas. Platelet-derived growth factor receptor- α and receptor- β , and their ligands A-chain and B-chain were positive in 14, 29, 19, and 62% of the solitary endometrioses, respectively. These results indicate activation of the platelet-derived growth factor pathway in ovarian clear-cell adenocarcinomas and suggest biological differences between carcinomas that arise in association with clear-cell Adenofibroma vs endometriosis.
Renthung Huang - One of the best experts on this subject based on the ideXlab platform.
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borderline clear cell Adenofibroma with extensive hemorrhagic necrosis
Hematology Oncology and Stem Cell Therapy, 2010Co-Authors: Renthung HuangAbstract:Borderline clear cell Adenofibroma of the ovary is rather rare since most of clear cell tumors are carcinomas. We report a case of ovarian borderline clear cell Adenofibroma in a 52-year-old postmenopausal woman. the tumor had the characteristic histologic features of borderline clear cell Adenofibroma except for central extensive hemorrhagic necrosis. the prognosis of borderline clear cell Adenofibroma is excellent. because the invasiveness cannot be assessed in the necrotic areas, our patient needed long-term follow-up.
Sohei Yamamoto - One of the best experts on this subject based on the ideXlab platform.
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Loss of ARID1A protein expression occurs as an early event in ovarian clear-cell carcinoma development and frequently coexists with PIK3CA mutations
Modern Pathology, 2012Co-Authors: Sohei Yamamoto, Hitoshi Tsuda, Masashi Takano, Seiichi Tamai, Osamu MatsubaraAbstract:ARID1A is a recently identified tumor suppressor gene that is mutated in ∼50% of ovarian clear-cell carcinomas. This mutation is associated with loss of ARID1A protein expression as assessed by immunohistochemistry. The present study aimed at determining the timing of the loss of ARID1A protein expression during the development of ovarian clear-cell carcinoma and assessing its relevance in correlation to PIK3CA gene mutations. A total of 42 clear-cell carcinoma cases with adjacent putative precursor lesions (endometriosis-associated carcinoma cases ( n =28) and (clear-cell) Adenofibroma-associated carcinoma cases ( n =14)) were selected and subjected to immunohistochemical analysis for ARID1A protein expression and direct genomic DNA sequencing of exons 9 and 20 of the PIK3CA gene. ARID1A immunoreactivity was deficient in 17 (61%) of the 28 endometriosis-associated carcinomas and 6 (43%) of the 14 Adenofibroma-associated carcinomas. Among the precursor lesions adjacent to the 23 ARID1A-deficient carcinomas, 86% of the non-atypical endometriosis (12 of 14) and 100% of the atypical endometriosis (14 of 14), benign (3 of 3), and borderline (6 of 6) clear-cell Adenofibroma components were found to be ARID1A deficient. In contrast, in the 19 patients with ARID1A-intact carcinomas, all of the adjacent precursor lesions retained ARID1A expression regardless of their types and cytological atypia. Analysis of 22 solitary endometrioses and 10 endometrioses distant from ARID1A-deficient carcinomas showed that all of these lesions were diffusely immunoreactive for ARID1A. Among the 42 clear-cell carcinomas, somatic mutations of PIK3CA were detected in 17 (40%) tumors and majority (71%) of these were ARID1A-deficient carcinomas. These results suggest that loss of ARID1A protein expression occurs as a very early event in ovarian clear-cell carcinoma development, similar to the pattern of PIK3CA mutation recently reported by our group, and frequently coexists (not mutually exclusive) with PIK3CA mutations.
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Expression of platelet-derived growth factors and their receptors in ovarian clear-cell carcinoma and its putative precursors
Modern Pathology, 2008Co-Authors: Sohei Yamamoto, Hitoshi Tsuda, Masashi Takano, Tsunekazu Kita, Kazuya Kudoh, Kenichi Furuya, Seiichi Tamai, Osamu MatsubaraAbstract:Recent studies have shown that platelet-derived growth factors and their receptors are frequently co-expressed in ovarian cancers. Herein, we investigated the role of the platelet-derived growth factor pathway in the development of ovarian clear-cell adenocarcinoma, a highly chemoresistant form of ovarian cancer. Immunohistochemical expression of platelet-derived growth factor receptor- α and receptor- β , platelet-derived growth factor A-chain and B-chain was examined in 31 cases of clear-cell adenocarcinoma and 56 coexisting putative precursor lesions: 17 non-atypical and 19 atypical endometrioses, and 10 non-atypical and 10 atypical clear-cell Adenofibroma components. Twenty-one solitary endometrioses were also examined. Vascular endothelial cells were always positive for all the markers examined, and were used as positive controls. The frequencies of positivity for platelet-derived growth factor receptor- α and receptor- β , and platelet-derived growth factor A-chain increased in accordance with higher cytologic atypia in the putative precursors: 71, 47, and 59% in the 17 non-atypical endometrioses, 84, 73, and 84% in the 19 atypical endometrioses, 0% each in the 10 non-atypical clear-cell Adenofibromas, 100, 90, and 90% in the 10 atypical clear-cell Adenofibromas, and 97, 97, and 100% in the 31 clear-cell adenocarcinomas, respectively. Positivity for platelet-derived growth factor B-chain increased in accordance with increased atypia in clear-cell Adenofibroma: 0% in non-atypical clear-cell Adenofibromas, 30% in atypical clear-cell Adenofibromas, and 60% in coexisting carcinomas. However, in contrast, positivity for platelet-derived growth factor B-chain decreased in accordance with increased atypia in endometriosis coexisting with clear-cell adenocarcinomas: 35% in non-atypical endometrioses, 11% in atypical endometrioses, and 5% in coexisting carcinomas. Platelet-derived growth factor receptor- α and receptor- β , and their ligands A-chain and B-chain were positive in 14, 29, 19, and 62% of the solitary endometrioses, respectively. These results indicate activation of the platelet-derived growth factor pathway in ovarian clear-cell adenocarcinomas and suggest biological differences between carcinomas that arise in association with clear-cell Adenofibroma vs endometriosis.
Robert J Kurman - One of the best experts on this subject based on the ideXlab platform.
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cystic and Adenofibromatous clear cell carcinomas of the ovary distinctive tumors that differ in their pathogenesis and behavior a clinicopathologic analysis of 122 cases
The American Journal of Surgical Pathology, 2009Co-Authors: Emanuela Veras, A Ayhan, S Ueda, Mutlu Hayran, Ie Ming Shih, Robert J KurmanAbstract:Ovarian clear cell carcinomas (CCC) typically present as large adnexal, stage I tumors and are generally considered highly malignant. They are frequently associated with endometriosis and, less often with clear cell Adenofibromas. We hypothesized that CCCs are a heterogeneous group of tumors, some a
Hitoshi Kitamura - One of the best experts on this subject based on the ideXlab platform.
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A case of ovarian endometrioid Adenofibroma of borderline malignancy: Evidence for estrogen-producing tumor
International Journal of Clinical Oncology, 1998Co-Authors: Etsuko Miyagi, Fumiki Hirahara, Yoshiaki Inayama, Itsuo Gorai, Hajime Yamaguchi, Tsuneo Nakazawa, Yoji Nagashima, Yukio Nakatani, Hiroshi Minaguchi, Hitoshi KitamuraAbstract:A case of ovarian endometrioid Adenofibroma of borderline malignancy with an increased serum estradiol level, which rapidly disappeared after removal of the tumor, is reported. Vaginal cytologic analysis showed estrogenic effects, and endometrial cystic glandular hyperplasia was thought to be the reason for genital bleeding. To determine the origin of estradiol production in the tumor, stromal cells were enzymatically isolated from the tumor and cultured in vitro. Estradiol levels in the cultured media increased in parallel with cell growth. This is the first report showing estrogen secretion from stromal cells in an ovarian endometrioid Adenofibroma.