The Experts below are selected from a list of 174 Experts worldwide ranked by ideXlab platform
Eleni Thodou - One of the best experts on this subject based on the ideXlab platform.
-
The gonadotroph origin of Null Cell Adenomas
Hormones, 2016Co-Authors: George Kontogeorgos, Eleni ThodouAbstract:AbstrAct OBJeCTIve: The term " Null Cell " Adenoma was first proposed in 1980 to designate pituitary Adenomas lacking clinical, biochemical and morphological markers to disclose their Cell origin. DESIGN: The aim of this study was to investigate the presence of α-and β-gonadotropin subunits in clinically nonfunctioning pituitary tumors, which were initially immunonegative and thus diagnosed as Null Cell Adenomas. for this reason, we reapplied immunohistochemistry using a more sensitive method comprising a tyramide signal amplification technique, combined with a polymer antibody immunohistochemical detection system. ResULTs: With this approach, all these previously negative tumors became positive for α-and β-gonadotropin hormone subunits. CONCLUsIONs: Our results prove that so-called " Null Cell " Adenomas produce α-SU or/and β-FSH or β-LH and therefore are gonadotrph Adenomas in origin.
A J Martinez - One of the best experts on this subject based on the ideXlab platform.
-
radiotherapy for nonfunctional pituitary Adenoma analysis of long term tumor control
Journal of Neurosurgery, 1998Co-Authors: Patrick Breen, Douglas Kondziolka, John C. Flickinger, A J MartinezAbstract:Object. The authors studied outcomes in patients who had undergone radiotherapy for nonfunctional pituitary Adenoma to assess long-term tumor control and to identify factors affecting tumor control such as higher radiation doses, improved imaging, and histological characteristics of the tumor. Methods. In this retrospective study, the authors evaluated 120 patients who received radiotherapy for nonfunctional pituitary Adenomas between 1960 and 1991. The median follow-up period was 9 years (range I month-32 years). Radiation doses varied between 37.6 and 65.6 Gy (median 46.7 Gy). Tumors progressed in 15 of the 120 patients by I to 25 years after radiotherapy. Actuarial tumor control rates at 10, 20, and 30 years were 87.5 ± 3.6%, 77.6 ± 6.3%, and 64.7 ± 12.9%, respectively. Tumor progression after radiotherapy occurred significantly more often (p = 0.0397) in patients with oncocytoma than in patients with nononcocytic Null Cell Adenoma. No other factors correlated significantly with tumor control. One case of optic and oculomotor neuropathy developed 4.5 years after a maximum dose of 50 Gy in 25 fractions. Radiation-induced neoplasms (meningioma and glioblastoma multiforme) developed at a rate of 2.7% at 10 and 30 years. Conclusions, The oncocytic variant of Null Cell pituitary Adenoma appears less sensitive to control by radiotherapy than nononcocytic undifferentiated Cell Adenoma. A follow-up period extending beyond 20 years is needed adequately to assess the efficacy of radiotherapy for tumor control. Doses of 40 or 45 Gy in 20 or 25 fractions, respectively, appear optimal.
-
Radiotherapy for nonfunctional pituitary Adenoma: Analysis of long term tumor control
International Journal of Radiation Oncology*Biology*Physics, 1998Co-Authors: Patrick B. Breen, John C. Flickinger, Douglas Kondziolka, A J MartinezAbstract:Object. The authors studied outcomes in patients who had undergone radiotherapy for nonfunctional pituitary Adenoma to assess long-term tumor control and to identify factors affecting tumor control such as higher radiation doses, improved imaging, and histological characteristics of the tumor. Methods. In this retrospective study, the authors evaluated 120 patients who received radiotherapy for nonfunctional pituitary Adenomas between 1960 and 1991. The median follow-up period was 9 years (range 1 month–32 years). Radiation doses varied between 37.6 and 65.6 Gy (median 46.7 Gy). Tumors progressed in 15 of the 120 patients by 1 to 25 years after radiotherapy. Actuarial tumor control rates at 10, 20, and 30 years were 87.5 ± 3.6%, 77.6 ± 6.3%, and 64.7 ± 12.9%, respectively. Tumor progression after radiotherapy occurred significantly more often (p = 0.0397) in patients with oncocytoma than in patients with nononcocytic Null Cell Adenoma. No other factors correlated significantly with tumor control. One case...
Oswaldo Inácio De Tella - One of the best experts on this subject based on the ideXlab platform.
-
Cirurgia endoscópica transnasal da região selar: estudo dos primeiros 100 casos
Arquivos de neuro-psiquiatria, 2003Co-Authors: Jackson A. Gondim, Michele Schops, Oswaldo Inácio De TellaAbstract:An endoscopic endonasal transsphenoidal approach to the sella was performed in 100 consecutive patients, with a follow up from 3 to 55 months: 57 females and 43 males, age ranging from 14 and 70 years. 76 cases pituitary Adenomas: 22 were acromegaly (7 microAdenomas and 15 macroAdenomas); 21 Null Cell Adenomas (3 microAdenomas and 18 macroAdenomas); 19 Cushing disease (11 microAdenomas and 8 macroAdenomas), 10 prolactinomas (6 microAdenomas and 4 macroAdenomas), and 4 LH Adenomas (4 macroAdenomas). In this serie, remission was achieved in 44.8% for macroAdenomas, 60% for acromegaly, 27.7% for Null Cell Adenoma, 50% for Cushing disease, 50% for prolactinomas and 50% for LH Adenomas, and 81.4% for microAdenomas 85% for acromegaly, 100% for Null Cell Adenoma, 81.8% for Cushing disease, 66% for prolactinoma. We had also four craniopharyngiomas, four sphenoidal mucocele, three sphenoidal aspergillus, one Rathke cyst, one hypophysitis, one cavernous aneurysm, one encefalocele, one intrasellar meningioma, one intrasellar tuberculoma and a sphenoid fibrous dysplasia. In this series we also had six fistulas of the anterior base that were completely cured. We had a mortality of 2, one Null Cell giant Adenoma in a 57 years old man and another patient, 38 years old, with a giant craniopharyngioma. The morbidity was: two cured meningitis, three cured fistulas, and two permanent diabetes insipidus. Endoscopic endonasal transsphenoidal surgery in this series resulted with comparable surgical outcomes to conventional microscopic transsphenoidal surgery. The advantages of this technique have been represented by an easier access to the lesion, better visualisation and increased illumination of the surgical sites, microdissection of the tumor with maximum preservation of the pituitary function, and reduction of hospitalization times and coasts. The main limits have been the reduction of field depth, constant need of manual control of the endoscope, and required experience of the endoscope technique.
-
Cirurgia endoscópica transnasal da região selar: estudo dos primeiros 100 casos Transnasal endoscopic surgery of the sellar region: study of the first 100 cases
Academia Brasileira de Neurologia (ABNEURO), 2003Co-Authors: Jackson Gondim, Michele Schops, Oswaldo Inácio De TellaAbstract:A abordagem neuroendoscópica transnasal para a sela túrcica foi realizada em 100 pacientes consecutivos com um seguimento variando entre 3 e 55 meses: 57 mulheres e 43 homens, com idade compreendida entre 14 e 70 anos; 76 eram Adenomas hipofisários: 22 acromegálicos (7 microAdenomas e 15 macroAdenomas), 21 Adenomas não secretores (3 microAdenomas e 18 macroAdenomas), 19 doença de Cushing (11 microAdenomas e 8 macroAdenomas), 10 prolactinomas (6 microAdenomas e 4 macroAdenomas), 4 Adenomas secretor de LH (4 macroAdenomas). A remissão da sintomatologia foi conseguida em 44,8% para os macroAdenomas (60% para acromegalia, 27,7% para os Adenomas não secretores, 50% para os pacientes com doença de Cushing, 50% para os prolactinomas, e 50% para os Adenomas secretantes de LH), e 81,4% para os microAdenomas (85% para acromegalia, 100% para os Adenomas não secretores, 81,8% para os pacientes com doença de Cushing, e 66% para os prolactinomas). Na série tivemos ainda quatro craniofaringeomas, quatro mucoceles esfenoidal, três aspergilose esfenoidal, e um caso de cada uma das patologias seguintes: cisto de Rathke, hipofisíte, aneurisma da carótida cavernosa, encefalocele, meningeoma intraselar, tuberculoma intra-selar e displasia fibrosa esfenoidal. Na série encontramos ainda seis fístulas liquóricas que foram todas fechadas através dessa via. A mortalidade foi de 2%, um paciente de 57 anos com um Adenoma gigante não produtor e um outro paciente de 38 anos com um volumoso craniofaringeoma predominantemente cístico. Como complicações tivemos duas meningites pós-operatórias curadas com antibioticoterapia e três fístulas pós-cirúrgica que foram reoperadas. Dois pacientes desenvolveram diabetes insípidus permanente. As vantagens desta técnica são representadas por um acesso mais fácil, melhor iluminação e visualização da lesão, mais fácil distinção entre tumor e hipófise normal, redução do tempo de hospitalização e dos custos hospitalares. As desvantagens são a diminuição da profundidade de campo, a necessidade de constante controle do endoscópio e a necessidade de maior experiência com as técnicas de endoscopia.An endoscopic endonasal transsphenoidal approach to the sella was performed in 100 consecutive patients, with a follow up from 3 to 55 months: 57 females and 43 males, age ranging from 14 and 70 years. 76 cases pituitary Adenomas: 22 were acromegaly (7 microAdenomas and 15 macroAdenomas); 21 Null Cell Adenomas (3 microAdenomas and 18 macroAdenomas); 19 Cushing disease (11 microAdenomas and 8 macroAdenomas), 10 prolactinomas (6 microAdenomas and 4 macroAdenomas), and 4 LH Adenomas (4 macroAdenomas). In this serie, remission was achieved in 44.8% for macroAdenomas, 60% for acromegaly, 27.7% for Null Cell Adenoma, 50% for Cushing disease, 50% for prolactinomas and 50% for LH Adenomas, and 81.4% for microAdenomas 85% for acromegaly, 100% for Null Cell Adenoma, 81.8% for Cushing disease, 66% for prolactinoma. We had also four craniopharyngiomas, four sphenoidal mucocele, three sphenoidal aspergillus, one Rathke cyst, one hypophysitis, one cavernous aneurysm, one encefalocele, one intrasellar meningioma, one intrasellar tuberculoma and a sphenoid fibrous dysplasia. In this series we also had six fistulas of the anterior base that were completely cured. We had a mortality of 2, one Null Cell giant Adenoma in a 57 years old man and another patient, 38 years old, with a giant craniopharyngioma. The morbidity was: two cured meningitis, three cured fistulas, and two permanent diabetes insipidus. Endoscopic endonasal transsphenoidal surgery in this series resulted with comparable surgical outcomes to conventional microscopic transsphenoidal surgery. The advantages of this technique have been represented by an easier access to the lesion, better visualisation and increased illumination of the surgical sites, microdissection of the tumor with maximum preservation of the pituitary function, and reduction of hospitalization times and coasts. The main limits have been the reduction of field depth, constant need of manual control of the endoscope, and required experience of the endoscope technique
Dieter K. Lüdecke - One of the best experts on this subject based on the ideXlab platform.
-
pathohistological classification of pituitary tumors 10 years of experience with the german pituitary tumor registry
European Journal of Endocrinology, 2007Co-Authors: Wolfgang Saeger, Dieter K. Lüdecke, Michael Buchfelder, Rudolf Fahlbusch, Hansjurgen Quabbe, Stephan PetersennAbstract:In 1996, the German Registry of Pituitary Tumors was founded by the Pituitary Section of the German Society of Endocrinology as a reference center for collection and consultant pathohistological studies of pituitary tumors. The experiences of the first 10 years of this registry based on 4122 cases will herein be reported. The data supplement former collections of the years 1970–1995 with 3480 surgically removed tumors or lesions of the pituitary region. The cases were studied using histology, immunostainings and in some cases also molecular pathology or electron microscopy. The Adenomas were classified according to the current World Health Organization classification in the version of 2004. From 1996 on 3489 Adenomas (84.6%), 5 pituitary carcinomas (0.12%), 133 craniopharyngiomas (3.2%), 39 meningiomas (0.94%), 25 metastases (0.6%), 22 chordomas (0.5%), 115 cystic non-neoplastic lesions (2.8%), and 46 inflammatory lesions (1.1%, 248 other lesions or normal tissue (6.0%)) were collected by us. The Adenomas (100%) were classified into densely granulated GH Cell Adenomas (9.2%), sparsely granulated GH Cell Adenomas (6.3%), sparsely granulated prolactin (PRL) Cell Adenomas (8.9%), densely granulated PRL Cell Adenomas (0.3%), mixed GH/PRL Cell Adenomas (5.2%), mammosomatotropic Adenomas (1.1%), acidophilic stem Cell Adenomas (0.2%), densely granulated ACTH Cell Adenomas (7.2%), sparsely granulated ACTH Cell Adenomas (7.9%), Crooke Cell Adenomas (0.03%), TSH Cell Adenomas (1.5%), FSH/LH Cell Adenomas (24.8%), Null Cell Adenomas (19.3%), Null Cell Adenoma, oncocytic variant (5.8%), and plurihormonal Adenomas (1.3%). Following the WHO classification of 2004, the new entity ‘atypical Adenoma’ was found in 12 cases in 2005. Various prognostic parameters and clinical implications are discussed.
-
Cyclins D1 and D3 and topoisomerase IIα in inactive pituitary Adenomas
Endocrine pathology, 2001Co-Authors: Wolfgang Saeger, Silke Schreiber, Dieter K. LüdeckeAbstract:The oncogenes cyclin D1 and D3 are overexpressed in many tumors. Topoisomerase IIα is found in proliferating Cells. The immunohistological expression of cyclin D1, cyclin D3, and Topoisomerase IIα was studied in a collection of 60 clinically inactive surgically removed pituitary Adenomas of the follicle-stimulating hormone/luteinizing hormone (FSH/LH) Cell complex (20 Null Cell Adenomas, 20 oncocytomas, and 20 FSH/LH Cell Adenomas) for correlation with other proliferation markers (Ki-67, PCNA) and with clinical data. Whereas cyclin D1 was positive only in one invasive Null Cell Adenoma (1.7%) with some p53-positive nuclei, cyclin D3 was overexpressed in the nuclei of 41 tumors (68%).
-
Androgen receptor in pituitary Adenomas of the gonadotroph Cell complex.
Pathology research and practice, 2000Co-Authors: Wolfgang Saeger, Silke Schreiber, Dieter K. LüdeckeAbstract:Summary Although androgen receptors have been identified in normal gonadotroph and somatotroph Cells of the pituitary, immunohistochemical studies have failed to reveal these receptors in pituitary Adenomas so far. Using a monoclonal antibody to androgen receptor in our series of 60 Adenomas of the gonadotroph Cell complex (20 FSH/LH Cell Adenomas, 20 Null Cell Adenomas, 20 oncocytic Adenomas), only one Null Cell Adenoma showed strong nuclear immunostaining. All the other antibodies were completely negative. The significance of this finding in correlation with clinical data is still unclear, although it may be associated with more rapid tumor growth. In paraadenomous tissue, some normal gonadotrophs expressed the androgen receptor.
-
DNA measurement, proliferation markers, and other factors in pituitary Adenomas
Endocrine Pathology, 1994Co-Authors: Angelika Krämer, Wolfgang Saeger, Gesche Tallen, Dieter K. LüdeckeAbstract:To assess the proliferative activity of pituitary Adenomas, 36 surgically removed Adenomas were studied by light microscopical parameters; mitotic count; expression of PCNA, Ki-67, cathepsin D, and EGF; and image cytometry. Three Adenomas (9%) showed high, 11 (34%) medium, 17 (53%) moderate, and 1 (3%) low structural differentiation. In 10 Adenomas (31%), no mitosis was observed. The average was 2.4 mitoses/100 HPF; the highest count was 7.1 mitoses/100 HPF. Eleven Adenomas (33.3%) were PCNA-negative; in 20 Adenomas (60.6%), between 0.05 and 3.9, and in 2 Adenomas (6.0%), between 10.5 and 16.4 PCNA-positive nuclei were observed. Only a recurrent Null-Cell Adenoma (9%) was Ki-67-negative. Three Adenomas (9.1%) were EGF-negative, 28 (84.8%) showed up to 10% positive Cells, and 2 (6.1 %) showed between 10 and 30% positive Cells; 19 Adenomas (68%) were cathepsin D-negative, including all endocrine-inactive Adenomas. Half the Adenomas had an euploid DMA stem line. Endocrine-inactive Adenomas displayed a higher rate of euploid DNA stem lines than endocrine-active Adenomas. The S-phase fraction varied between 2.97 and 28%, with a mean value of 14.4%. Half the Adenomas showed an S-phase fraction of 11.65% or lower.
George Kontogeorgos - One of the best experts on this subject based on the ideXlab platform.
-
The gonadotroph origin of Null Cell Adenomas
Hormones, 2016Co-Authors: George Kontogeorgos, Eleni ThodouAbstract:AbstrAct OBJeCTIve: The term " Null Cell " Adenoma was first proposed in 1980 to designate pituitary Adenomas lacking clinical, biochemical and morphological markers to disclose their Cell origin. DESIGN: The aim of this study was to investigate the presence of α-and β-gonadotropin subunits in clinically nonfunctioning pituitary tumors, which were initially immunonegative and thus diagnosed as Null Cell Adenomas. for this reason, we reapplied immunohistochemistry using a more sensitive method comprising a tyramide signal amplification technique, combined with a polymer antibody immunohistochemical detection system. ResULTs: With this approach, all these previously negative tumors became positive for α-and β-gonadotropin hormone subunits. CONCLUsIONs: Our results prove that so-called " Null Cell " Adenomas produce α-SU or/and β-FSH or β-LH and therefore are gonadotrph Adenomas in origin.
