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Pancreatic Neoplasms: HELP
Articles by Ozgur Mete
Based on 5 articles published since 2010
(Why 5 articles?)

Between 2010 and 2020, Özgür Mete wrote the following 5 articles about Pancreatic Neoplasms.
+ Citations + Abstracts
1 Review Endocrine manifestations of von Hippel-Lindau disease. 2015

Cassol, Clarissa / Mete, Ozgur. ·From the Department of Pathology, University Health Network, Toronto, Ontario, Canada, and the Department of Laboratory Medicine and Pathobiology, University of Toronto, Ontario, Canada. ·Arch Pathol Lab Med · Pubmed #25611110.

ABSTRACT: von Hippel-Lindau (VHL) disease is an autosomal dominant disorder caused by heterozygous mutations in the VHL tumor suppressor gene that is characterized by the occurrence of multiple endocrine and nonendocrine lesions. This review focuses on the endocrine manifestations of VHL disease. Pancreatic neuroendocrine proliferations (ductuloinsular complexes, islet dysplasia, endocrine microadenoma, and neuroendocrine tumors), pheochromocytomas, and extra-adrenal paragangliomas are important endocrine manifestations of VHL disease. They frequently display characteristic clinical, biochemical, and histopathologic features that, although not pathognomonic, can be helpful in suggesting VHL disease as the underlying etiology and distinguishing these tumors from sporadic cases. Recent improvements in treatment and outcomes of renal cell carcinomas have allowed pancreatic neuroendocrine tumors to emerge as a significant source of metastatic disease, making the accurate recognition and classification of these neoplasms by the pathologist of utmost importance to determine prognosis, treatment, and follow-up strategies for affected patients.

2 Article The Impact of Phosphohistone-H3-Assisted Mitotic Count and Ki67 Score in the Determination of Tumor Grade and Prediction of Distant Metastasis in Well-Differentiated Pancreatic Neuroendocrine Tumors. 2016

Ozturk Sari, Sule / Taskin, Orhun Cig / Gundogdu, Gokcen / Yegen, Gulcin / Onder, Semen / Keskin, Metin / Saglam, Sezer / Ozluk, Yasemin / Gulluoglu, Mine / Mete, Ozgur. ·Department of Pathology, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Turkey. suleozturksari@gmail.com. · Department of Pathology, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Turkey. · Department of General Surgery, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Turkey. · Department of Medical Oncology, University of Bilim, Istanbul, Turkey. · Department of Pathology, University Health Network, Toronto, ON, Canada. · Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada. ·Endocr Pathol · Pubmed #26936845.

ABSTRACT: This study investigated the impact of phosphohistone-H3 (PHH3)-assisted mitotic count by comparing its performance with conventional mitotic count and Ki67 score as well as the status of distant metastasis. A total of 43 surgically resected pancreatic neuroendocrine tumors (panNET) with complete follow-up information has been subjected to a standardized assessment with respect to mitotic count (both conventional and PHH3-assisted) and Ki67 score. Five participants assessed mitotic count and the time spent was recorded in both methods. All tumors were assigned to a G1 category of mitotic rate on conventional mitotic count that failed to identify three tumors with a G2 category of mitotic rate on PHH3. Near-perfect and fair agreements were achieved among observers when using PHH3 and conventional method, respectively. The mean time spent to determine mitotic count on PHH3-stained slides was significantly shorter (p < 0.001). The performance of PHH3-assisted mitotic grade category was significant as the three cases with a G2 mitotic category were associated with distant metastasis (p = 0.01). Despite its performance, the PHH3-assisted mitotic count downgraded 17 cases that were classified as G2 based on Ki67 scores in this series. The Ki67 grade category was either the same or higher than the mitotic grade category. Ten patients developed distant metastasis. Eleven tumors exhibited vascular invasion characterized by intravascular tumor cells admixed with thrombus. Our results indicate that PHH3-assisted mitotic count facilitates an accurate mitotic count with a perfect agreement among observers. The small size of this cohort is an important limitation of the current study, a G2 mitotic grade category based on PHH3 immunohistochemistry was one of the correlates of panNETs with distant metastasis. While the prognostic impact of PHH3-assisted mitotic count needs to be clarified in larger cohorts, Ki67 scores designated higher grade category in all cases; thus, it was the best determinant of the tumor grade. More importantly, the presence of vascular invasion along with the Ki67 grade category was found to be independent predictors of distant metastasis.

3 Article Hormone profiling, WHO 2010 grading, and AJCC/UICC staging in pancreatic neuroendocrine tumor behavior. 2013

Morin, Emilie / Cheng, Sonia / Mete, Ozgur / Serra, Stefano / Araujo, Paula B / Temple, Sara / Cleary, Sean / Gallinger, Steven / Greig, Paul D / McGilvray, Ian / Wei, Alice / Asa, Sylvia L / Ezzat, Shereen. ·Department of Medicine, Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario, Canada. ·Cancer Med · Pubmed #24403235.

ABSTRACT: Pancreatic neuroendocrine tumors (pNETs) are the second most common pancreatic neoplasms, exhibiting a complex spectrum of clinical behaviors. To examine the clinico-pathological characteristics associated with long-term prognosis we reviewed 119 patients with pNETs treated in a tertiary referral center using the WHO 2010 grading and the American Joint Committee on Cancer/International Union Against Cancer (AJCC/UICC) staging systems, with a median follow-up of 38 months. Tumor size, immunohistochemistry (IHC) profiling and patient characteristics-determining stage were analyzed. Primary clinical outcomes were disease progression or death. The mean age at presentation was 52 years; 55% were female patients, 11% were associated with MEN1 (multiple endocrine neoplasia 1) or VHL (Von Hippel-Lindau); mean tumor diameter was 3.3 cm (standard deviation, SD) (2.92). The clinical presentation was incidental in 39% with endocrine hypersecretion syndromes in only 24% of cases. Nevertheless, endocrine hormone tissue immunoreactivity was identified in 67 (56.3%) cases. According to WHO 2010 grading, 50 (42%), 38 (31.9%), and 3 (2.5%) of tumors were low grade (G1), intermediate grade (G2), and high grade (G3), respectively. Disease progression occurred more frequently in higher WHO grades (G1: 6%, G2: 10.5%, G3: 67%, P = 0.026) and in more advanced AJCC stages (I: 2%, IV: 63%, P = 0.033). Shorter progression free survival (PFS) was noted in higher grades (G3 vs. G2; 21 vs. 144 months; P = 0.015) and in more advanced AJCC stages (stage I: 218 months, IV: 24 months, P < 0.001). Liver involvement (20 vs. 173 months, P < 0.001) or histologically positive lymph nodes (33 vs. 208 months, P < 0.001) were independently associated with shorter PFS. Conversely, tissue endocrine hormone immunoreactivity, independent of circulating levels was significantly associated with less aggressive disease. Age, gender, number of primary tumors, and heredity were not significantly associated with prognosis. Although the AJCC staging and WHO 2010 grading systems are useful in predicting disease progression, tissue endocrine hormone profiling provides additional information of potentially important prognostic value.

4 Article Inhibin-expressing clear cell neuroendocrine tumor of the ampulla: an unusual presentation of von Hippel-Lindau disease. 2013

Gucer, Hasan / Szentgyorgyi, Eva / Ezzat, Shereen / Asa, Sylvia L / Mete, Ozgur. ·Department of Pathology, University Health Network, 200 Elizabeth Street, 11th floor, Toronto, Ontario,, M5G 2C4, Canada. ·Virchows Arch · Pubmed #23913169.

ABSTRACT: von Hippel-Lindau (VHL) disease is a hereditary autosomal dominant disorder associated with deletions or mutations in the VHL tumor suppressor gene. Characteristically, up to 60 % of neuroendocrine tumors (NETs) associated with VHL disease display a spectrum of clear cell morphology including multivacuolated lipid-rich cell change. Unlike neurofibromatosis type 1 and multiple endocrine neoplasia type 1 syndromes, ampullary NETs have not been described in association with VHL disease. In this report, we discuss the features of an incidental ampullary clear cell NET occurring in a patient with pancreatic VHL disease including multiple pancreatic NETs. The ampullary lesion consisted of epithelial cells resembling lipoblasts or signet ring cells. In our case, all NETs showing clear cell change were positive for inhibin. While the underlying mechanism of this finding is largely unknown, it is of note that positivity for inhibin has not been observed in clear cell NETs associated with multiple endocrine neoplasia type 1 syndrome. Our case proves that NETs can develop in the ampullary region in patients with VHL; clear cell change can occur in these lesions and can mimic signet ring cell carcinoma. This issue is of clinical significance especially in small biopsy samples; thus, positivity for keratin alone should not be taken as evidence of an adenocarcinoma. Moreover, demonstration of inhibin expression in a NET with clear cell change along with other clinical stigmata should alert the diagnostician to the possibility of VHL disease. However, further larger series examining inhibin expression in both syndrome-related and sporadic clear cell NETs are needed to confirm our findings.

5 Article An unusual clinical presentation of pancreatic solid pseudopapillary tumor with ovarian metastases: a diagnostic dilemma. 2011

Mete, Özgür / Yegen, Gülçin / Güllüoglu, Mine G / Kapran, Yersu / Klöppel, Günter. ·Istanbul University, Istanbul Faculty of Medicine, Department of Pathology, Istanbul, Turkey. ozgurmete77@gmail.com ·Int J Surg Pathol · Pubmed #21447535.

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