mPRs represent a novel target for PRL inhibition in experimental prolactinomas.

Membrane progesterone receptors are known to mediate rapid nongenomic progesterone effects in different cell types. Recent evidence revealed that mPRα is highly expressed in the rat pituitary, being primarily localized in lactotrophs, acting as an intermediary of P4-inhibitory actions on prolactin secretion. The role of mPRs in prolactinoma development remains unclear. We hypothesize that mPR agonists represent a novel tool for hyperprolactinemia treatment. To this end, pituitary expression of mPRs was studied in three animal models of prolactinoma. Expression of mPRs and nuclear receptor was significantly decreased in tumoral pituitaries compared to normal ones. However, the relative proportion of mPRα and mPRß was highly increased in prolactinomas. Interestingly, the selective mPR agonist (Org OD 02-0) significantly inhibited PRL release in both normal and tumoral pituitary explants, displaying a more pronounced effect in tumoral tissues. As P4 also regulates PRL secretion indirectly, by acting on dopaminergic neurons, we studied mPR involvement in this effect. We found that the hypothalamus has a high expression of mPRs. Interestingly, both P4 and OrgOD 02-0 increased dopamine release in hypothalamus explants. Moreover, in an in vivo treatment, that allows both, pituitary and hypothalamus actions, the mPR agonist strongly reduced the hyperprolactinemia in transgenic females carrying prolactinoma. Finally, we also found and interesting gender difference: males express higher levels of pituitary mPRα/ß, a sex that does not develop prolactinoma in these mice models. Taken together, these findings suggest mPRs activation could represent a novel tool for hyperprolactinemic patients, especially those that present resistance to dopaminergic drugs.

Negative correlation between tumour size and cortisol/ACTH ratios in patients with Cushing's disease harbouring microadenomas or macroadenomas.

PURPOSE: Pituitary macroadenomas (MACs) represent 10-30 % of Cushing's disease (CD) cases. The aim of this study was to report the clinical, laboratorial and imaging features and postsurgical outcomes of microadenoma (MIC) and MAC patients. METHODS: Retrospective study with 317 CD patients (median 32 years old, range 9-71 years) admitted between 1990 and 2014, 74 (23.3 %) of whom had MAC. RESULTS: Hirsutism, plethora facial, muscular weakness and muscular atrophy were more frequent in the MIC patients. Nephrolithiasis, osteopenia, hyperprolactinaemia and galactorrhoea were more prevalent in MAC patients. The morning serum cortisol (Fs), nocturnal salivary cortisol (NSC), nocturnal Fs (Fs 2400 h), low- and high-dose dexamethasone suppression test results and CRH and desmopressin test results were similar between the subgroups. MIC patients showed higher urinary cortisol at 24 h (UC), and MAC patients presented higher ACTH levels but lower Fs/ACTH, Fs 2400 h/ACTH, NSC/ACTH and UC/ACTH ratios. There were negative correlations of tumour size with Fs/ACTH, Fs 2400 h/ACTH, NSC/ACTH and UC/ACTH ratios. Overall, the postsurgical remission and recurrence rates were similar between MIC and MAC. However, patients in remission (MIC + MAC) showed smaller tumour diameters and a lower prevalence of invasion and extension on MRI. CONCLUSIONS: Despite exhibiting higher plasma ACTH levels, CD patients with MAC presented lower cortisol/ACTH ratios than did patients with MIC, with a negative correlation between tumour size and cortisol/ACTH ratios. The overall postsurgical remission and recurrence rates were similar between MIC and MAC patients, with those with larger and/or invasive tumours showing a lower remission rate.

[Pseudo-pituitary tumor and hypopituitarism secondary to a sphenoid sinus inverted papilloma]. / Pseudo-tumor pituitario e hipopituitarismo secundario a un papiloma invertido del seno esfenoidal.

Inverted papilloma (IP) is a benign uncommon epithelial tumor, arising mostly from the lateral nasal wall. Though benign, this lesion is highly invasive into surrounding tissues and malignant transformation may occur. Primary IP of the sphenoid sinus and intracranial extension with dural invasion, even without histological evidence of malignancy, has only rarely been described. Hypopituitarism as a complication of this lesion has never been reported. We describe the case of a 59-year-old woman who was evaluated because of a 5-year-history of severe headaches and abnormalities in the visual field. Magnetic resonance imaging (MRI) showed a 1.4 per 2.0 cm heterogeneous sellar lesion with suprasellar and sphenoid sinus extension, eroding the sellar floor with optic chiasm compression. Otolaryngologists gave her 16 mg/day of prednisone during approximately 3 months with a near total regression of the mass on MRI. The endocrine biochemical evaluation showed pituitary gonadal, thyroid and adrenal insufficiency. A new MRI showed growth of the tumor with obliteration of the sphenoid sinus. An endoscopic sinus biopsy revealed an IP, so a transnasal endoscopic sinus surgery was performed with complete resection evidenced by MRI a year later.

Pseudo-tumor pituitario e hipopituitarismo secundario a un papiloma invertido del seno esfenoidal / Pseudo-pituitary tumor and hypopituitarism secondary to a sphenoid sinus inverted papilloma

El papiloma invertido (PI) es un tumor epitelial benigno, poco frecuente, que se origina mayormente de la pared nasal lateral. A pesar de ser benigno, constituye una lesión altamente invasiva de tejidos vecinos y puede sufrir una transformación maligna. El PI primario del seno esfenoidal con extensión intracraneana e invasión dural, aun sin evidencia histológica de malignidad, ha sido excepcionalmente descrito. Describimos el caso de una mujer de 59 años de edad que fue evaluada por cefaleas intensas de 5 años de evolución y anormalidades del campo visual. Una resonancia magnética nuclear (RMN) mostró una masa selar heterogénea de 1.4 por 2 cm con extensión supraselar y al seno esfenoidal, con erosión del piso selar y compresión del quiasma óptico. Recibió 16 mg/día de prednisona durante aproximadamente 3 meses con una regresión casi total de la masa en la RMN. En la evaluación hormonal se halló insuficiencia gonadal, tiroidea y adrenal central. En una nueva RMN se observó crecimiento del tumor con compromiso total del seno esfenoidal. Una biopsia endoscópica confirmó el diagnóstico de PI. Se realizó una cirugía sinusal transnasal endoscópica con una resección completa evidenciada en una RMN un año más tarde.

nverted papilloma (IP) is a benign uncommon epithelial tumor, arising mostly from the lateral nasal wall. Though benign, this lesion is highly invasive into surrounding tissues and malignant transformation may occur. Primary IP of the sphenoid sinus and intracranial extension with dural invasion, even without histological evidence of malignancy, has only rarely been described. Hypopituitarism as a complication of this lesion has never been reported. We describe the case of a 59-year-old woman who was evaluated because of a 5-year-history of severe headaches and abnormalities in the visual field. Magnetic resonance imaging (MRI) showed a 1.4 per 2.0 cm heterogeneous sellar lesion with suprasellar and sphenoid sinus extension, eroding the sellar floor with optic chiasm compression. Otolaryngologists gave her 16 mg/day of prednisone during approximately 3 months with a near total regression of the mass on MRI. The endocrine biochemical evaluation showed pituitary gonadal, thyroid and adrenal insufficiency. A new MRI showed growth of the tumor with obliteration of the sphenoid sinus. An endoscopic sinus biopsy revealed an IP, so a transnasal endoscopic sinus surgery was performed with complete resection evidenced by MRI a year later.

Pseudo-tumor pituitario e hipopituitarismo secundario a un papiloma invertido del seno esfenoidal / Pseudo-pituitary tumor and hypopituitarism secondary to a sphenoid sinus inverted papilloma

El papiloma invertido (PI) es un tumor epitelial benigno, poco frecuente, que se origina mayormente de la pared nasal lateral. A pesar de ser benigno, constituye una lesión altamente invasiva de tejidos vecinos y puede sufrir una transformación maligna. El PI primario del seno esfenoidal con extensión intracraneana e invasión dural, aun sin evidencia histológica de malignidad, ha sido excepcionalmente descrito. Describimos el caso de una mujer de 59 años de edad que fue evaluada por cefaleas intensas de 5 años de evolución y anormalidades del campo visual. Una resonancia magnética nuclear (RMN) mostró una masa selar heterogénea de 1.4 por 2 cm con extensión supraselar y al seno esfenoidal, con erosión del piso selar y compresión del quiasma óptico. Recibió 16 mg/día de prednisona durante aproximadamente 3 meses con una regresión casi total de la masa en la RMN. En la evaluación hormonal se halló insuficiencia gonadal, tiroidea y adrenal central. En una nueva RMN se observó crecimiento del tumor con compromiso total del seno esfenoidal. Una biopsia endoscópica confirmó el diagnóstico de PI. Se realizó una cirugía sinusal transnasal endoscópica con una resección completa evidenciada en una RMN un año más tarde.(AU)

nverted papilloma (IP) is a benign uncommon epithelial tumor, arising mostly from the lateral nasal wall. Though benign, this lesion is highly invasive into surrounding tissues and malignant transformation may occur. Primary IP of the sphenoid sinus and intracranial extension with dural invasion, even without histological evidence of malignancy, has only rarely been described. Hypopituitarism as a complication of this lesion has never been reported. We describe the case of a 59-year-old woman who was evaluated because of a 5-year-history of severe headaches and abnormalities in the visual field. Magnetic resonance imaging (MRI) showed a 1.4 per 2.0 cm heterogeneous sellar lesion with suprasellar and sphenoid sinus extension, eroding the sellar floor with optic chiasm compression. Otolaryngologists gave her 16 mg/day of prednisone during approximately 3 months with a near total regression of the mass on MRI. The endocrine biochemical evaluation showed pituitary gonadal, thyroid and adrenal insufficiency. A new MRI showed growth of the tumor with obliteration of the sphenoid sinus. An endoscopic sinus biopsy revealed an IP, so a transnasal endoscopic sinus surgery was performed with complete resection evidenced by MRI a year later.(AU)

Pseudo-tumor pituitario e hipopituitarismo secundario a un papiloma invertido del seno esfenoidal. / [Pseudo-pituitary tumor and hypopituitarism secondary to a sphenoid sinus inverted papilloma].

Inverted papilloma (IP) is a benign uncommon epithelial tumor, arising mostly from the lateral nasal wall. Though benign, this lesion is highly invasive into surrounding tissues and malignant transformation may occur. Primary IP of the sphenoid sinus and intracranial extension with dural invasion, even without histological evidence of malignancy, has only rarely been described. Hypopituitarism as a complication of this lesion has never been reported. We describe the case of a 59-year-old woman who was evaluated because of a 5-year-history of severe headaches and abnormalities in the visual field. Magnetic resonance imaging (MRI) showed a 1.4 per 2.0 cm heterogeneous sellar lesion with suprasellar and sphenoid sinus extension, eroding the sellar floor with optic chiasm compression. Otolaryngologists gave her 16 mg/day of prednisone during approximately 3 months with a near total regression of the mass on MRI. The endocrine biochemical evaluation showed pituitary gonadal, thyroid and adrenal insufficiency. A new MRI showed growth of the tumor with obliteration of the sphenoid sinus. An endoscopic sinus biopsy revealed an IP, so a transnasal endoscopic sinus surgery was performed with complete resection evidenced by MRI a year later.

Diagnóstico diferencial de los prolactinomas / Differential diagnosis of prolactinomas

La hiperprolactinemia puede deberse tanto a adenomas hipofisarios que secretan prolactina (prolactinomas) como a tumores selares no funcionantes (denominados seudoprolactinomas). La relación entre el tamaño del tumor y el grado de prolactinemia habitualmente permite distinguir los prolactinomas de los seudoprolactinomas; este diagnóstico diferencial es esencial, dado que la terapia es completamente diferente (médica en el primer caso, quirúrgica en el último). La posible coexistencia de otras causas fisiológicas, patológicas o yatrogénicas de hiperprolactinemia, así como artefactos de laboratorio (efecto gancho) y la presencia de variantes de prolactina desprovistas de actividad biológica (macroprolactinas) puede dar origen a errores. Los médicos deben conocer estos trastornos, dado que cuando no se reconocen se pueden realizar tratamientos inapropiados.

Regulation of pituitary function by cytokines.

Research performed on the pituitary has proven that cytokines play an important role in maintaining pituitary physiology, affecting not only cell proliferation but also hormone secretion. The effects of cytokines can be autocrine or paracrine. This review gives an overview on the effects of the most studied cytokines in the pituitary. Special interest is focused on interleukin-6 (IL-6) because it has the distinctive characteristic of stimulating pituitary tumor cell growth, but has the opposite effect on normal pituitary cells. On the other hand, IL-6 is a cytokine of interest in the pituitary because recent work has shown that it promotes and maintains senescence in certain types of tumors. Given that the majority of pituitary adenomas are microadenomas and the fact that clinically inapparent pituitary tumors are quite common, senescence, perhaps mediated by IL-6, is an attractive mechanism for explaining the benign nature of pituitary tumors.

Gonadotrofinomas: análisis multicéntrico y retrospectivo de 66 pacientes / Gonadotrophinomas: multicenter and retrospective analysis of 66 patients

Objetivo: Analizar la presentación clínica, radiológica, bioquímica y el comportamiento posquirúrgico de una cohorte de pacientes portadores de gonadotrofinomas. Pacientes y Métodos: Se evaluaron pacientes con gonadotrofinomas estudiados en nueve centros endocrinológicos de la ciudad de Bs.As. durante el período 1983 a 2003. El criterio de inclusión fue la inmunohistoquímica (IH) positiva para hormona luteinizante (LH), folículoestimulante (FSH) y/o alfa subunidad (ASU). Los adenomas plurihormonales fueron excluidos. Resultados: Fueron analizados 66 pacientes de 51,8 ± 12,1 (X +/- DS) años (39 varones). Los síntomas mas frecuentemente observados fueron las alteraciones visuales (72,8%), seguidas por el hipogonadismo y las cefaleas. El 10,6% se diagnosticaron en forma incidental. El 98,5% fueron macroadenomas, 56,9% de los cuales correspondieron a un estadio Hardy (EH) 3 y 29,6% a un EH 4. El tiempo de seguimiento fue de 47,8 meses (r: 5-168). El hipogonadismo definido bioquímicamente se presentó en el 82,4% de los pacientes. En su mayoría presentaban niveles bajos o inapropiadamente normales de gonadotrofinas, pero 4 mujeres y 3 varones presentaron niveles séricos elevados y disociados de FSH y LH. La hiperprolactinemia por desconexión fue observada en 45,2% de la población (X: 65.6 ng/ml r: 30-172). El hipopituitarismo se detectó en 25,7% de los casos. La cirugía fue transeptoesfenoidal (TSE) en 80%; una segunda operación fue realizada en el 28% de la población. La IH fue positiva por orden de frecuencia para LH, FSH y ASU o las 3 combinaciones. La evolución posquirúrgica evidenció mejoría en el campo visual (CV) en el 41%. La presencia de restos tumorales y/o recidiva fue del 84%. Se indicó radioterapia en 37% y la sustitución hormonal fue necesaria en el 65% de los pacientes.

The aim of our study was to describe the clinical-biochemical and radiologic presentation and the post surgery outcome in a cohort of patients with gonadotrophinomas. Patients were selected from nine Endocrinology Units of the city of Buenos Aires from 1983 at 2003. The inclusion criteria was defined by nonfunctinoning pituitary adenomas with positive innmunohistochemical (IH) for luteinizing hormone (LH), follicle-stimulating hormone (FSH) and/or alpha subunit (ASU). Innmunohistochemically plurihormonal adenomas were excluded. Sixty six patients were analyzed, aged 51,8 ± 12,1 (X +/- DS) years; (39 men). More prevalent symptoms were visual alterations (72,8%), hypogonadism and headaches. Eleven percent was diagnosed as incidentalomas. Ninety eight percent were macroadenomas, 56,9% was Hardy stage (HS) 3 and 29,6% was HS 4. The patients were followed up for 47,8 months (r: 5-168). Hypogonadism was biochemically found in 82,4%. The majority showed low or inappropriately normal levels of gonadotrophins except for 4 women and 3 men that had high and dissociated levels. Hyperprolactinemia was observed in 45,2% and was interpreted as an interference with normal dopamine inhibition of prolactin secretion (X+/-DS: 65.6+/- ng/ml, r: 30-172). Hypopituitarism was found in 25,7% of the patients. Transsphenoidal surgery was carried out in 80% and in 28% a second surgery was needed. The IH was positive for LH, FSH and ASU in this order of frequency or its combinations. Tumor persistency and/or recurrency were found in 84% of the patients. Forty one percent showed improvement of visual defects. Radiotherapy was indicated in 37% and hormonal replacement was needed in 65% of the patients.

Silent corticotroph adenomas

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).

Silent corticotroph adenomas.

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% 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% 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.

Tumorigênese hipofisária / Pituitary tumorigenesis

Os tumores hipofisários, adenomas na sua quase totalidade, representam de 10 por cento a 15 por cento das neoplasias intracranianas (1) e são encontrados em até 27 por cento de autópsias não selecionadas, como achado incidental (2). Morfologicamente são classificados em microadenomas (< 1cm de diâmetro) e macroadenomas, que podem ser circunscritos, invasivos e/ou expansivos. Do ponto de vista funcional, são divididos em adenomas secretores (de PRL, GH, ACTH, TSH, LH e FSH, podendo co-secretar dois ou mais hormônios) e clinicamente não secretores ou "não funcionantes". O diagnóstico é feito pelo fenótipo da hipersecreção (acromegalia, Cushing etc.) e, nos macroadenomas com efeito de massa, por hipopituitarismo e/ou distúrbios neurológicos, onde predominam as queixas visuais e cefaléia. Quanto aos mecanismos de tumorigênese hipofisária, a disputa entre causa primária hipotalâmica versus hipofisária ganhou força a favor da segunda graças às evidências da monoclonalidade dos tumores, juntamente com outros argumentos como a ausência de tecido hiperplásico circundando o adenoma cirurgicamente removido e a relativa independência do controle hipotalâmico. No entanto, admite-se que um papel permissivo do hipotálamo é importante para a progressão tumoral. Muitos mecanismos moleculares envolvidos na tumorigenese hipofisária já foram desvendados, incluindo oncogenes, genes supressores tumorais e fatores de crescimento, e serão descritos neste artigo de revisão.

Adenomas hipofisários produtores de glicoproteínas: patogênese, diagnóstico e tratamento / Glycoprotein-secreting pituitary adenomas: pathogenesis, diagnosis and treatment

Os adenomas hipofisários produtores de glicoproteínas compreendem duas entidades clínicas e patológicas distintas: os adenomas gonadotróficos e os tirotróficos. Embora possam ser agrupados por produzirem hormônios e/ou sub-unidades que são glicoproteínas, esses tumores se originam em tipos celulares distintos (gonadotrofos e tirotrofos) que são apenas remotamente relacionados. Os gonadotróficos estão entre os adenomas hipofisários mais comuns, correspondendo à grande maioria dos assim chamados adenomas "não-funcionantes", silenciosos ou clinicamente não-secretores, enquanto os tirotróficos são extremamente raros e clinicamente se apresentam com hipertiroidismo por secreção inapropriada de TSH. Nesse artigo, os autores revisam aspectos epidemiológicos, patológicos, patogenéticos, clínicos, diagnósticos e terapêuticos desses adenomas. Uma ênfase maior foi dada à patogênese molecular dos tumores hipofisários em geral, buscando, sempre que possível, contrastar as alterações moleculares encontradas nesses adenomas com outros tipos de adenomas hipofisários. No lado mais prático, a experiência dos autores de mais de duas décadas no diagnóstico e tratamento desses tumores na Unidade de Neuroendocrinologia da Unifesp, foi criteriosamente utilizada para discutir a literatura disponível nesses tópicos.

Regulation of pituitary hormones and cell proliferation by components of the extracellular matrix

The extracellular matrix is a three-dimensional network of proteins, glycosaminoglycans and other macromolecules. It has a structural support function as well as a role in cell adhesion, migration, proliferation, differentiation, and survival. The extracellular matrix conveys signals through membrane receptors called integrins and plays an important role in pituitary physiology and tumorigenesis. There is a differential expression of extracellular matrix components and integrins during the pituitary development in the embryo and during tumorigenesis in the adult. Different extracellular matrix components regulate adrenocorticotropin at the level of the proopiomelanocortin gene transcription. The extracellular matrix also controls the proliferation of adrenocorticotropin-secreting tumor cells. On the other hand, laminin regulates the production of prolactin. Laminin has a dynamic pattern of expression during prolactinoma development with lower levels in the early pituitary hyperplasia and a strong reduction in fully grown prolactinomas. Therefore, the expression of extracellular matrix components plays a role in pituitary tumorigenesis. On the other hand, the remodeling of the extracellular matrix affects pituitary cell proliferation. Matrix metalloproteinase activity is very high in all types of human pituitary adenomas. Matrix metalloproteinase secreted by pituitary cells can release growth factors from the extracellular matrix that, in turn, control pituitary cell proliferation and hormone secretion. In summary, the differential expression of extracellular matrix components, integrins and matrix metalloproteinase contributes to the control of pituitary hormone production and cell proliferation during tumorigenesis.

Regulation of pituitary hormones and cell proliferation by components of the extracellular matrix.

The extracellular matrix is a three-dimensional network of proteins, glycosaminoglycans and other macromolecules. It has a structural support function as well as a role in cell adhesion, migration, proliferation, differentiation, and survival. The extracellular matrix conveys signals through membrane receptors called integrins and plays an important role in pituitary physiology and tumorigenesis. There is a differential expression of extracellular matrix components and integrins during the pituitary development in the embryo and during tumorigenesis in the adult. Different extracellular matrix components regulate adrenocorticotropin at the level of the proopiomelanocortin gene transcription. The extracellular matrix also controls the proliferation of adrenocorticotropin-secreting tumor cells. On the other hand, laminin regulates the production of prolactin. Laminin has a dynamic pattern of expression during prolactinoma development with lower levels in the early pituitary hyperplasia and a strong reduction in fully grown prolactinomas. Therefore, the expression of extracellular matrix components plays a role in pituitary tumorigenesis. On the other hand, the remodeling of the extracellular matrix affects pituitary cell proliferation. Matrix metalloproteinase activity is very high in all types of human pituitary adenomas. Matrix metalloproteinase secreted by pituitary cells can release growth factors from the extracellular matrix that, in turn, control pituitary cell proliferation and hormone secretion. In summary, the differential expression of extracellular matrix components, integrins and matrix metalloproteinase contributes to the control of pituitary hormone production and cell proliferation during tumorigenesis.

Cirugía transnasal transesfenoidal endoscópica en afecciones de región selar / Endoscopic transsphenoidal transnasal surgery in affections of the sellar region

Para un gran número de tumores pituitarios la cirugía es el tratamiento de primera línea y el abordaje transesfenoidal microquirúrgico el más utilizado. En estos momentos este procedimiento se ejecuta tanto por la vía microscópica como endoscópica. Recientemente el abordaje transnasal endoscópico ha irrumpido como una opción en desarrollo, que pudiera llegar a predominar en un futuro próximo. El objetivo del presente trabajo fue evaluar, mediante el análisis de los resultados, y - si es posible - realizar en nuestro medio el abordaje transnasal transesfenoidal endoscópico para las lesiones de la región selar con resultados quirúrgicos al menos similares a los obtenidos con el método microquirúrgico tradicional. Se realizó una investigación limitada tipo cohorte, estrictamente controlada y prospectiva, de 10 pacientes seleccionados según criterios de inclusión, a quienes se les practicó el abordaje transnasal endoscópico como método de tratamiento quirúrgico, entre agosto del año 2002 y el mismo mes de 2003, en el servicio de Neurocirugía del Hospital "Hermanos Ameijeiras". Se operaron 6 casos que tenían macroadenomas hipofisarios: 3 productores de hormona del crecimiento (GH), 1 secretor de prolactina (PRL) y otros 2 no productores. A los 4 restantes se les había diagnosticado fístula de líquido cefalorraquídeo (LCR) a través del piso selar. De los 6 macroadenomas, en 5 se logró exéresis total del tumor, mientras que en el otro se obtuvo exéresis subtotal. La rinorrea desapareció en 2 pacientes con fístula de LCR y se mantuvo en los otros 2. De las complicaciones observadas en el 30(por ciento) de los casos, solo en 1 (10 por ciento) trascendieron más allá del transoperatorio. Se concluye que los resultados obtenidos con la utilización del método transnasal endoscópico hacen el procedimiento en nuestro medio lo suficientemente seguro como para justificar su realización, y a su vez efectuar estudios posteriores aleatorizados y controlados, en busca de información más consistente en relación con el valor real de la técnica, a estas alturas del desarrollo de la cirugía hipofisaria(AU)

Cirugía transeptoesfenoidal en adenomas hipofisarios productores de prolactina / Transeptosphenoidal surgery in prolactin-secreting hypophyseal adenomas

El tratamiento actual de los prolactinomas es básicamente médico, teniendo en cuenta los buenos resultados alcanzados con los nuevos agonistas dopaminérgicos. No obstante, la adenomectomía selectiva clasifica entre las modalidades de tratamiento para aquellos prolactinomas que no respondan a este. El objetivo del presente trabajo fue evaluar los resultados del tratamiento microquirúrgico por vía transeptoesfenoidal de los adenomas productores de prolactina en el servicio de Neurocirugía del Hospital Hermanos Ameijeiras, para lo cual presentamos un estudio retrospectivo y descriptivo de 63 pacientes intervenidos por vía sublabial transeptoesfenoidal microquirúrgica portadores de este tipo de adenomas, y tratados en nuestro servicio desde 1996 hasta el 2003. Se analizaron la edad, el sexo, el cuadro clínico, el tamaño de las lesiones, los niveles hormonales, así como las complicaciones y la evolución posoperatoria. Como resultado se encontró un franco predominio del sexo femenino: 86(por ciento) (54 pacientes). Se operaron 31 pacientes con macroadenomas y 32 con microadenomas. Los síntomas más frecuentes mejoraron, sobre todo la cefalea, en el 82(por ciento) (36 casos) y los trastornos visuales en el 69 (18 casos). La complicación más común en el posoperatorio fue la diabetes insípida transitoria (11 enfermos). Se logró reducir las cifras iniciales de prolactina a valores no tumorales en el 90,6 de lo microadenomas (29 casos) y en el 67,7 de los macroadenomas (21 casos). Se concluye que la adenomectomía transeptoesfenoidal es un proceder seguro y eficaz como opción de tratamiento para pacientes con adenomas secretores de prolactina que tengan indicación quirúrgica(AU)

[Pituitary tumorigenesis]. / Tumorigênese hipofisária.

Pituitary adenomas, almost invariably adenomas, account for 10% to 15% of all intracranial neoplasms and are incidentally detected in up to 27% of non selected autopsies. They are morphologically classified as microadenomas (diameter < 1 cm) or macroadenomas, which can be enclosed, invasive and/or expansive. Functionally, they are classified as secreting adenomas (PRL, GH, ACTH, TSH, LH, and FSH, and those co-secreting two or more hormones), and clinically non secreting or "non functioning" tumors. Diagnosis is based on the hypersecretion phenotype (acromegaly, Cushing, etc), and on mass effect of macroadenomas leading to neurological disturbances, mainly visual complaints and headache. Pituitary tumorigenesis mechanisms include those of primary hypothalamic versus pituitary origin, the latter is supported by evidence of pituitary adenoma monoclonality, as well as the absence of hyperplastic tissue surrounding the surgically removed tumor, and the relative independence of tumor hypothalamic control. Nevertheless, a permissive role of the hypothalamus on tumor progression is also postulated. Several molecular mechanisms involved in pituitary tumorigenesis have been unraveled including oncogenes, tumor suppressor genes and growth factors involved in neoplastic development, and will be described in this review.