Expression of E-cadherin, Slug and NCAM and its relationship to tumor invasiveness in patients with acromegaly

Pituitary adenomas account for 10-15% of primary intracranial tumors. Growth hormone (GH)-secreting adenomas account for 13% of all pituitary adenomas and cause acromegaly. These tumors can be aggressive, invade surrounding structures and are highly recurrent. The objective of this study was to evaluate E-cadherin, Slug and neural cell adhesion molecule (NCAM) expression in GH-secreting pituitary adenomas and its relationship to tumor invasiveness. A cross-sectional study of patients who underwent hypophysectomy due to GH-secreting pituitary adenoma from April 2007 to December 2014 was carried out. The medical records were reviewed to collect clinical data. Immediately after surgery, tumor samples were frozen in liquid nitrogen and stored in a biofreezer at -80°C for assessment of E-cadherin 1 (CDH1), SLUG (SNAI2), and NCAM (NCAM1) by real-time PCR. The samples were fixed in formalin and embedded in paraffin for immunohistochemical analysis of E-cadherin and NCAM. Thirty-five patients with acromegaly were included in the study. Of these, 65.7% had invasive tumors. Immunohistochemically, E-cadherin was expressed in 96.7% of patients, and NCAM in 80% of patients. There was no statistically significant relationship between tumor grade or invasiveness and immunohistochemical expression of these markers. Regarding gene expression, 50% of cases expressed CDH1, none expressed SNAI2, and 53.3% expressed NCAM1. There was no statistically significant relationship between tumor grade or invasiveness and gene expression of CDH1, SNAI2, and NCAM1. The absence of Slug overexpression and of E-cadherin and NCAM suppression suggests that expression of these markers is not associated with tumor invasiveness in GH-secreting pituitary adenomas.

Expression of merlin, NDRG2, ERBB2, and c-MYC in meningiomas: relationship with tumor grade and recurrence

Meningiomas are common, usually benign tumors of the central nervous system that have a high rate of post-surgical recurrence or regrowth. We determined expression of the proteins merlin, NDRG2, ERBB2, and c-MYC in meningiomas using immunohistochemistry and assessed relationships between protein expression and gender, age, tumor grade, and recurrence or regrowth. The study sample comprised 60 patients, (44 women and 16 men) with a mean age of 53.2±12.7 years. Tumors were classified as grade I (n=48) or grades II and III (n=12). Expression of merlin, NDRG2, ERBB2, and c-MYC was not significantly different statistically with relation to gender, age, or meningioma recurrence or regrowth. Merlin was expressed in 100% of the cases. No statistically significant difference between tumor grade and recurrence or regrowth was identified. Statistically significant differences were identified between the mean age of patients with grade I (54.83±11.60) and grades II and III (46.58±15.08) meningiomas (P=0.043), between strong c-MYC expression and grades II and III (P<0.001), and between partial surgical resection and tumor recurrence or regrowth (P<0.001). These findings reveal the lower mean age among grades II and III meningioma patients than grade I patients, the influence of the protein merlin on tumorigenesis, the association of c-MYC with aggressive meningiomas, and that partial surgical resection is associated with tumor recurrence or regrowth.

Abundant immunohistochemical expression of dopamine D2 receptor and p53 protein in meningiomas: follow-up, relation to gender, age, tumor grade, and recurrence

Meningiomas are common, usually benign tumors, with a high postoperative recurrence rate. However, the genesis and development of these tumors remain controversial. We aimed to investigate the presence and implications of a mutated p53 protein and dopamine D2 receptor in a representative series of meningiomas and to correlate these findings with age, gender, tumor grade, and recurrence. Tumor tissue samples of 157 patients diagnosed with meningioma (37 males and 120 females, mean age 53.6±14.3 years) who underwent surgical resection between 2003 and 2012 at our institution were immunohistochemically evaluated for the presence of p53 protein and dopamine D2 receptor and were followed-up to analyze tumor recurrence or regrowth. Tumors were classified as grades I (n=141, 89.8%), II (n=13, 8.3%), or grade III (n=3, 1.9%). Dopamine D2 receptor and p53 protein expression were positive in 93.6% and 49.7% of the cases, respectively. Neither of the markers showed significant expression differences among different tumor grades or recurrence or regrowth statuses. Our findings highlight the potential role of p53 protein in meningioma development and/or progression. The high positivity of dopamine D2 receptor observed in this study warrants further investigation of the therapeutic potential of dopamine agonists in the evolution of meningiomas.

Measurement of Ki-67 antigen in 159 pituitary adenomas using the MIB-1 monoclonal antibody

Pituitary adenomas sometimes show rapid growth and recurrence, and about one third invade the structures surrounding the sella turcica. In an attempt to determine aggressive behavior at an early stage, we used the MIB-1 antibody to identify the Ki-67 antigen. The present study was designed to evaluate pituitary adenomatous tissue in terms of secretion and proliferation and to correlate the Ki-67 index with hormone phenotype and invasive behavior. Material from 159 patients submitted to one or more resections of pituitary adenomas was evaluated. Forty-two non-secretory adenomas and 43 adenomas immunoreactive for growth hormone, 19 for prolactin, 18 for growth hormone and prolactin, 16 for adrenocorticotropic hormone (ACTH), and 21 cases of plurihormonal/gonadotropin adenomas were detected by immunohistochemistry. The MIB-1 antibody was positive in 139 samples and the Ki-67 index ranged from 0.16 to 15.48 percent (mean = 1.22 ± 2.09 percent), with no significant difference between genders, age groups, or secretory and non-secretory status. The Ki-67 index was higher in ACTH-secreting adenomas. Invasive pituitary adenomas had a significantly higher Ki-67 index (2.01 ± 3.15 percent) than macroadenomas with or without supra-sellar extension (1.12 ± 1.87 percent; P = 0.02). The index was not significantly different in the subgroup of adenomas with invasion of the cavernous sinus compared to groups with other types of invasion. We conclude that tumoral proliferative activity evaluated by the detection of the Ki-67 antigen is significantly higher in invasive than noninvasive adenomas, information which can be useful in therapeutic postoperative management since index cut-off values associated with aggressive behavior can be established.

Expression of p53 protein in pituitary adenomas

Inactivating mutations of TP53, a tumor suppressor gene, are associated with abnormal cell proliferation. Although p53 expression is common in many human malignancies, p53 protein has seldom been evaluated in pituitary tumors. When detected, the percentage of p53-positive cells is low, and, in general, it is exclusive for invasive lesions. The aim of the present study was to use immunohistochemistry to determine the presence of p53 protein in pituitary adenomas from tumor samples of 163 surgeries performed in 148 patients (40 percent male, 60 percent female). In 35 percent of the cases the adenoma was nonfunctional, while in the others it was associated with PRL, GH and/or ACTH endocrine hypersecretion syndrome. Macroadenomas were observed in 83.2 percent of the cases with available neuroimage evaluation, of which 28 percent invaded the cavernous, sphenoid and/or ethmoidal sinus, bone, third ventricle or subfrontal lobe. p53 protein was detected in 2/148 patients (1.3 percent). Immunohistochemistry was positive for PRL and GH in these cases. Due to the high percentage of invasive pituitary adenomas found in our study, the low frequency of p53 detection suggests that it is inadequate as a routine marker for aggressiveness and as a predictive factor of tumor behavior

Adenomas da hipófise: estudo imuno-histoquímico de 167 casos / Pituitary adenomas: immunohistochemical study of 167 cases

Foram analisados 167 casos de adenomas da hipófise pelo método imuno-histoquímico utilizando o Complexo da Avidina Biotina (ABC) descrito por HSU e col. (1981). Foram usados 6 anti-hormônios hipofisários: anti-prolactina (aPRL), na diluiçäo de 1:1.500, anti-hormônio do crescimento (aHGH), na diluiçäo de 1:4.000, anti-hormônio adrenocorticotrófico (aACTH), na diluiçäo de 1:3.000, anti-hormônio tireotrófico (aTSH), na diluiçäo de trófico (aACTH), na diluiçäo de 1:3.000, anti-hormônio tireotrófico (aTSH), na diluiçäo de 1:3.000, anti-hormônio luteinizante (aLH), na diluiçäo de 1:1.000, anti-hormônio folículo estimulante (a(FSH), na diluiçäo de 1;3.000. O período de incubaçäo foi de 14 a 16 horas a 4-C. Foi realizada também a coloraçäo pelo Orange G-PAS. O levantamento dos dados clínicos, laboratoriais, e radiológicos dos casos de adenomas de hipófise foi realizado após leitura das lâminas pelo método imuno-histoquímico. Dos 167 casos de adenomas da hipófise, 136 (81,4%) mostraram imuno-reaçäo positiva a um ou mais anti-hormônios, variando o índice de positividade entre 1 e 90% das células neoplásicas. A imuno-reaçäo foi positiva exclusivamente a um anti-hormônio em 80 casos (58,8%) e para dois ou mais anti-hormônios nos 56 casos restantes (41,2%), sendo a associaçäo mais freqüentemente encontrada aquela em que a positividade ocorreu para o aPRL e o aHGH. A positividade a reaçäo imuno-histoquímica distribuiu-se da seguinte forma: 100 casos foram positivos para o aPRL, em 49 pacientes de forma isolada; 65 casos foram positivos para o aHGH, em 22 pacientes de forma isolada; 31 casos foram positivos para o aACTH, em 8 pacientes de forma isolada; 5 casos foram positivos ao aTSH, em um paciente de forma isolada; um paciente apresentou adenoma positivo ao aLH; um caso foi positivo ao aFSH

Metastases intracranianas. Estudo de 147 casos. / Intracranial metastases: Study of 147 cases

Sao analisados 147 casos de metastases intracranianas quanto a distribuicao etaria, manifestacoes clinicas, topografia, orgaos de origem, tipos histologicos e resultados obtidos pelas terapeuticas instituidas. Os criterios de selecao para o tratamento cirurgico sao comentados

Tumores raqueanos: a proposito de 100 casos. / Spinal tumors: apropos of 100 cases

Sao estudados 100 casos de tumores raqueanos quanto a distribuicao etaria, tipo histologico, topografia, evolucao e manifestacoes clinicas. Os diversos achados sao comparados com os da literatura