Differential expression of menin in sporadic pituitary adenomas.

2004 ◽  
Vol 11 (2) ◽  
pp. 333-344 ◽  
Author(s):  
M Theodoropoulou ◽  
I Cavallari ◽  
L Barzon ◽  
D M D'Agostino ◽  
T Ferro ◽  
...  
Keyword(s):  
Pituitary Adenomas ◽  
Anterior Lobe ◽  
Nuclear Staining ◽  
Human Pituitary ◽  
Human Pituitary Gland ◽  
Putative Tumor Suppressor ◽  
The Status ◽  
Normal Human ◽  
Strong Nuclear Staining

Pituitary adenomas represent one of the key features of multiple endocrine neoplasia type 1. The gene involved in this syndrome (MEN1) is a putative tumor suppressor, that codes for a 610-amino acid nuclear protein termed 'menin'. Analyses of sporadic pituitary adenomas have so far failed to reveal MEN1 mutations or defects in MEN1 transcription in these tumors. In the present study we detected menin protein expression in a panel of normal and tumoral pituitary tissues, using a monoclonal antibody against the carboxy-terminus of menin. In the normal human pituitary gland, strong nuclear staining for menin was detectable in the majority of the endocrine cells of the anterior lobe, without a clear association with a particular hormone-producing type. In sporadic pituitary adenomas, menin expression was variable, with a high percentage of cases demonstrating a significant decrease in menin immunoreactivity when compared with the normal pituitary. Interestingly, metastatic tissues derived from one pituitary carcinoma had no detectable menin levels. Altogether, our data provide the first information regarding the status of menin expression in human normal and neoplastic pituitary as determined by immunohistochemistry (IHC).

Fine Structural Classification of Chromophobe Adenomas of the Human Pituitary Gland

1975 ◽  
Vol 33 ◽  
pp. 378-379
Author(s):  
K. Kovacs ◽  
E. Horvath
Keyword(s):  
Pituitary Adenomas ◽  
Secretory Activity ◽  
Microscopic Investigation ◽  
Uranyl Acetate ◽  
Electron Microscopic Investigation ◽  
Electron Microscopic ◽  
Human Pituitary ◽  
Cytoplasmic Staining ◽  
Human Pituitary Gland ◽  
Microscopic Features

Chromophobe pituitary adenomas arise from adenohypophysial cells and fail to exhibit cytoplasmic staining with conventional acid or basic dyes by light microscopy. The aim of the present work was to study the electron microscopic features of these tumors, to separate them into distinct entities and to correlate their fine structural appearances with secretory activity.Among 48 surgically removed various pituitary adenomas 30 tumors were found which, based on the tinctorial characteristics of the cytoplasm, corresponded to chromophobe adenomas. For electron microscopic investigation pieces of these tumors were fixed in 2.5 per cent glutaraldehyde in Sorensen's buffer, post fixed in 1 per cent osmium tetroxide in Millonig's buffer, dehydrated in graded ethanol and embedded in Epon 812. Ultrathin sections were stained with uranyl acetate and lead citrate.By electron microscopy it was possible to separate chromophobe adenomas into 3 distinct entities: 1) adenomas consisting of sparsely granulated growth hormone cells (7 cases).

scholarly journals MEN4 and CDKN1B mutations: the latest of the MEN syndromes

2017 ◽  
Vol 24 (10) ◽  
pp. T195-T208 ◽  
Author(s):  
Rami Alrezk ◽  
Fady Hannah-Shmouni ◽  
Constantine A Stratakis
Keyword(s):  
Tumor Suppressor ◽  
Neuroendocrine Tumors ◽  
Pituitary Adenomas ◽  
Wide Spectrum ◽  
Susceptibility Gene ◽  
Germline Mutations ◽  
Suppressor Gene ◽  
Loss Of Function ◽  
Putative Tumor Suppressor

Multiple endocrine neoplasia (MEN) refers to a group of autosomal dominant disorders with generally high penetrance that lead to the development of a wide spectrum of endocrine and non-endocrine manifestations. The most frequent among these conditions is MEN type 1 (MEN1), which is caused by germline heterozygous loss-of-function mutations in the tumor suppressor geneMEN1. MEN1 is characterized by primary hyperparathyroidism (PHPT) and functional or nonfunctional pancreatic neuroendocrine tumors and pituitary adenomas. Approximately 10% of patients with familial or sporadic MEN1-like phenotype do not haveMEN1mutations or deletions. A novel MEN syndrome was discovered, initially in rats (MENX), and later in humans (MEN4), which is caused by germline mutations in the putative tumor suppressorCDKN1B. The most common phenotype of the 19 established cases of MEN4 that have been described to date is PHPT followed by pituitary adenomas. Recently, somatic or germline mutations inCDKN1Bwere also identified in patients with sporadic PHPT, small intestinal neuroendocrine tumors, lymphoma and breast cancer, demonstrating a novel role forCDKN1Bas a tumor susceptibility gene for other neoplasms. In this review, we report on the genetic characterization and clinical features of MEN4.

scholarly journals Differential Regulation of Proopiomelanocortin and Pituitary-Restricted Transcription Factor (TPIT), a New Marker of Normal and Adenomatous Human Corticotrophs

2003 ◽  
Vol 88 (7) ◽  
pp. 3050-3056 ◽  
Author(s):  
Sophie Vallette-Kasic ◽  
Dominique Figarella-Branger ◽  
Michel Grino ◽  
Anne-Marie Pulichino ◽  
Henry Dufour ◽  
...  
Keyword(s):  
Transcription Factor ◽  
In Situ Hybridization ◽  
Pituitary Adenomas ◽  
Experimental Models ◽  
Pituitary Cells ◽  
Human Pituitary ◽  
T Box ◽  
Normal Human ◽  
Human Anterior Pituitary

Since the identification of the pituitary-restricted transcription factor Tpit, a novel T-box factor that is only present in mouse in the two pituitary proopiomelanocortin (POMC)-expressing lineages, no information was available on its pattern of expression in human pituitary. We investigated by immunohistochemistry and in situ hybridization the expression of TPIT in normal human anterior pituitary tissue and in several types of human pituitary adenomas (n = 52). TPIT expression was restricted to the nucleus of normal or adenomatous human corticotroph cells. No specific TPIT immunostaining was detectable in all prolactin (PRL)-, GH-, or gonadotropin-secreting adenomas. In situ hybridization studies demonstrated that TPIT transcripts were coexpressed with POMC mRNA in both secreting and silent corticotroph adenomas, and in normal corticotrophs, whereas TPIT mRNA was not detectable in other types of pituitary adenomas. Unlike POMC, TPIT was not up-regulated by adrenalectomy in rats and did not seem down-regulated in the normal pituitary adjacent to human corticotroph microadenomas. TPIT is the only currently known transcription factor selectively expressed in human normal and adenomatous corticotrophs. In human and experimental models, TPIT and its target gene POMC were thus differentially regulated by glucocorticoids. Moreover, TPIT represents a new marker of POMC-expressing pituitary cells.

Arterial blood supply of the normal human pituitary gland

1983 ◽  
Vol 58 (5) ◽  
pp. 678-681 ◽  
Author(s):  
Toussaint A. Leclercq ◽  
Francois Grisoli
Keyword(s):  
Pituitary Gland ◽  
Blood Supply ◽  
Arterial Blood Supply ◽  
Human Pituitary ◽  
Content Type ◽  
Human Pituitary Gland ◽  
Normal Pituitary Gland ◽  
Arterial Blood ◽  
Normal Human

✓ A technique for the removal of sphenoid blocks from cadavers and for selective injection of the hypophyseal arteries of these specimens is described. Results of such injections are presented, with emphasis on the role of the inferior hypophyseal artery (IHA). The IHA was found to be the most important artery supplying the pituitary gland, and in particular, the structures involved in production, transportation, and storage of the antidiuretic hormone. The literature pertinent to the arterial blood supply of the normal pituitary gland is reviewed.

Sign in / Sign up

Export Citation Format

Share Document