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1.
Clinics ; 68(6): 887-891, jun. 2013. tab, graf
Article in English | LILACS | ID: lil-676940

ABSTRACT

OBJECTIVE: The expression of transcription factors involved in early pituitary development, such as PROP1 and POU1F1, has been detected in pituitary adenoma tissues. In this study, we sought to characterize the transcriptional profiles of PROP1, POU1F1, and TBX19 in functioning and nonfunctioning pituitary adenomas in an attempt to identify their roles in tumorigenesis and hormone hypersecretion. METHODS: RT-qPCR analyses were performed to assess the transcriptional pattern of PROP1, POU1F1, TBX19, and hormone-producing genes in tissue samples of corticotrophinomas (n = 10), somatotrophinomas (n = 8), and nonfunctioning adenomas (n = 6). RESULTS: Compared with normal pituitary tissue, POU1F1 was overexpressed in somatotrophinomas by 3-fold. PROP1 expression was 18-fold higher in corticotrophinomas, 10-fold higher in somatotrophinomas, and 3-fold higher in nonfunctioning adenomas. TBX19 expression was 27-fold higher in corticotrophinomas. Additionally, the level of TBX19 mRNA positively correlated with that of pro-opiomelanocortin (r = 0.49, p = 0.014). CONCLUSIONS: Our data demonstrate that PROP1 is overexpressed in pituitary adenomas, mainly in corticotrophinomas. Together with previously published data showing that patients who harbor PROP1 loss-of-function mutations present a progressive decline in corticotrope function, our results support a role for PROP1 in pituitary tumor development and in the maintenance of cell lineages committed to corticotrophic differentiation. .


Subject(s)
Adolescent , Adult , Aged , Female , Humans , Male , Middle Aged , Young Adult , ACTH-Secreting Pituitary Adenoma/metabolism , Adenoma/metabolism , Homeodomain Proteins/metabolism , Neoplasm Proteins/metabolism , T-Box Domain Proteins/metabolism , Transcription Factor Pit-1/metabolism , ACTH-Secreting Pituitary Adenoma/genetics , ACTH-Secreting Pituitary Adenoma/pathology , Adenoma/genetics , Adenoma/pathology , Cell Differentiation , Homeodomain Proteins/genetics , Immunohistochemistry , Neoplasm Proteins/genetics , Pituitary Gland , Real-Time Polymerase Chain Reaction , RNA, Messenger/metabolism , T-Box Domain Proteins/genetics , Transcription Factor Pit-1/genetics , Transcription Factors/genetics , Transcription Factors/metabolism
2.
Arq. bras. endocrinol. metab ; 51(8): 1314-1318, nov. 2007.
Article in English | LILACS | ID: lil-471747

ABSTRACT

Silent corticotroph pituitary adenomas (SCA) are defined as pituitary adenomas showing positive staining for adrenocorticotrophic hormone in immunohistochemical studies, but not associated with perioperative clinical or laboratory features of hypercortisolaemia. They account for 1.1-6 percent of surgically removed pituitary adenomas. Currently, two distinct pathologic subtypes of SCA are recognised. Their pathogenesis remains unclear. They present with local mass effects (headache, visual deterioration, cranial nerve palsies, endocrine dysfunction). The lack of manifestations of cortisol excess has not been conclusively explained. In surgical series, most tumours are macroadenomas with suprasellar extension present in 87-100 percent of the cases; this is in contrast to Cushing's disease, which is mostly attributed to microadenomas. Surgery remains the main therapeutic approach. Attempts to identify predictors of recurrence have not been successful. Management and follow-up protocols should be planned taking into account their potential aggressive behaviour, particularly upon recurrence. The development of florid pituitary Cushing's syndrome and local recurrence followed by metastatic disease (occasionally outside the central nervous system) have been rarely reported.


Adenomas corticotróficos silenciosos (ACS) são definidos como adenomas hipofisários que apresentam coloração positiva para o hormônio adrenocorticotrófico em estudos imuno-histoquímicos, mas não são associados com achados clínicos ou laboratoriais peri-operatórios de hipercortisolemia. São responsáveis por 1,1-6 por cento dos adenomas hipofisários removidos cirurgicamente. Atualmente, dois subtipos patológicos distintos de ACS são reconhecidos, mas sua patogênese permanece obscura. Eles se apresentam com efeitos de massa local (cefaléia, deterioração visual, paralisia de nervos cranianos, disfunção endócrina). A ausência de manifestações de excesso de cortisol não é suficientemente explicada. Em séries cirúrgicas, a maioria dos tumores são macroadenomas com extensão suprasselar, presente em 87-100 por cento dos casos, em contraste com a doença de Cushing, que é principalmente atribuída a microadenomas. A cirurgia continua a principal ação terapêutica. A tentativa de se identificar preditores de recorrência tem sido mal sucedida. Protocolos de manejo e acompanhamento devem ser planejados levando-se em consideração o seu comportamento potencialmente agressivo, particularmente na recorrência. Raramente tem sido reportado o desenvolvimento de síndrome de Cushing hipofisária florida e recorrência local, seguida de doença metastática (ocasionalmente fora do sistema nervoso central).


Subject(s)
Humans , ACTH-Secreting Pituitary Adenoma/pathology , Adenoma/pathology , Pituitary Neoplasms/pathology , ACTH-Secreting Pituitary Adenoma/etiology , ACTH-Secreting Pituitary Adenoma/therapy , Adenoma/etiology , Adenoma/therapy , Adrenocorticotropic Hormone/analysis , Immunohistochemistry , Pituitary Neoplasms/etiology , Pituitary Neoplasms/therapy
3.
Arq. bras. endocrinol. metab ; 51(8): 1355-1361, nov. 2007. ilus, tab
Article in English | LILACS | ID: lil-471752

ABSTRACT

Transsphenoidal pituitary surgery (TSS) remains the treatment of choice for Cushing's disease (CD). Despite the widespread acceptance of this procedure as the first line treatment in CD, the indication of a second TSS in not cured or relapsed DC patients is not consensus. We report the results of TSS in 108 patients with CD (a total of 117 surgeries). The mean postoperative follow-up period was 6 years. Remission was defined as clinical and laboratorial signs of adrenal insufficiency, period of glucocorticoid dependence, serum cortisol suppression on oral 1-mg dexamethasone overnight suppression test and clinical remission of hypercortisolism. We evaluated 103 patients with CD by the time of the first TSS. Fourteen patients underwent second TSS (5 had already been operated in others centers; in 5 patients the first surgery was not curative; in 4 patients CD relapsed). Remission rates were 85.4 percent and 28.6 percent (p < 0.001) after first and second TSS, respectively. In microadenomas, remission rates were higher than macroadenomas (94.9 percent vs. 73.9 percent; p = 0.006). In patients with negative pituitary imaging remission rates were 71.4 percent (p = 0.003; vs. microadenomas). Postoperative complications were: transient diabetes insipidus, definitive diabetes insipidus, hypopituitarism, stroke and one death. Only hypopituitarism was more frequent after second TSS (p = 0.015). In conclusion, TSS for CD is an effective and safe treatment. The best remission rates were observed at the first surgery and in microadenomas. The low remission rates after a second TSS suggest that this approach could not be a good therapeutic choice when the first one was not curative.


O tratamento de escolha para a doença de Cushing (DC) ainda é a cirurgia transesfenoidal (CTE) para ressecção do adenoma hipofisário produtor de ACTH. Porém, a indicação de uma segunda CTE representa uma questão controversa, tanto nos pacientes não curados após a primeira cirurgia quanto nos casos de recidiva. Neste trabalho, relatamos os resultados da CTE em 108 pacientes com DC (totalizando 117 cirurgias). O tempo médio de seguimento foi de 6 anos. Critérios de cura: ocorrência de insuficiência adrenal (clínica ou laboratorial), período de dependência ao glicocorticóide, supressão do cortisol sérico pós-1 mg de dexametasona overnight e remissão clínica do hipercortisolismo. Foram avaliados 103 pacientes com DC submetidos à primeira CTE. Quatorze pacientes foram submetidos a uma segunda CTE (5 já tinham sido operados em outros centros; a primeira cirurgia não fora curativa em 5; 4 pacientes com recidiva da DC). Índices de cura: 85,4 por cento e 28,6 por cento (p < 0,001) após a primeira e segunda CTE, respectivamente. Nos microadenomas, remissão maior que nos macroadenomas (94,9 por cento vs. 73,9 por cento; p = 0,006). Nos pacientes com imagem hipofisária negativa, cura foi de 71,4 por cento (p = 0,003; vs. micro). Complicações pós-operatórias: diabetes insipidus transitório e definitivo, hipopituitarismo, acidente vascular cerebral e um óbito. Apenas a ocorrência de hipopituitarismo foi mais freqüente após a segunda CTE (p = 0,015). Assim sendo, a CTE para a DC representa uma terapêutica efetiva e segura. Os melhores índices de cura foram obtidos na primeira cirurgia e em microadenomas. O baixo índice de cura após a segunda CTE sugere que esta abordagem não deve ser considerada uma boa opção terapêutica quando a primeira cirurgia não for curativa.


Subject(s)
Adolescent , Adult , Aged , Child , Female , Humans , Male , Middle Aged , ACTH-Secreting Pituitary Adenoma/surgery , Adenoma/surgery , Hypophysectomy/standards , Pituitary ACTH Hypersecretion/surgery , Pituitary Neoplasms/surgery , Sphenoid Sinus/surgery , ACTH-Secreting Pituitary Adenoma/pathology , Adenoma/pathology , Follow-Up Studies , Hypophysectomy/methods , Pituitary Neoplasms/pathology , Postoperative Complications/diagnosis , Recurrence , Remission Induction , Reoperation , Treatment Outcome
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