Pituitary Adenomas Associated with Signs of Endocrine Activity

Author(s):  
Alex M. Landolt
Author(s):  
Vânia Nosé ◽  
E. Tessa Hedley-Whyte

A wide variety of distinct pathological conditions may affect the pituitary, causing hormonal dysfunction and/or compression of surrounding structures. This chapter describes and illustrates the main pituitary lesions. Pituitary adenomas represent 10% to 20% of intracranial neoplasms in neurosurgical series. Their classifications are based on multiple factors, including histology and immunohistochemistry, ultrastructure and endocrine activity. Pituitary carcinomas are extremely rare. Pituitary hyperplasia is a rare cause of pituitary hyperfunction. Inflammatory (lymphocytic hypophysitis, granulomatous hypophysitis) and vascular (pituitary infarction, pituitary apoplexy, Sheehan syndrome) lesions can cause hypopituitarism. Craniopharyngiomas are the second most common neoplasm of the sellar region, following pituitary adenomas, and the most common suprasellar neoplasm in children.


2014 ◽  
Vol 10 (02) ◽  
pp. 124
Author(s):  
Ali GENC ◽  
Halil Ibrahim SUN ◽  
Burcu KASAPOGLU ◽  
Pinar Oz ◽  
Murat Aydın SAV ◽  
...  

Pituitary tumors are the most common form of intracranial neoplasms. However, clinically relevant pituitary tumors presenting with disturbances of hormonal secretion or mass effect are rare and they only represent about 10 % of all surgically resected intracranial neoplasms. Prolactinomas are the most common types of pituitary adenomas. Generally, hormonal expression patterns provided by immunohistochemistry (IHC) studies are correlated with the clinical features and endocrine activity of the patients. Nonetheless, exceptions occur where the immunocytochemical staining is not concordant with the clinical picture. Pituitary adenomas presenting with apoplexy are well known. However, pituitary adenomas causing cerebral stroke and resulting in hemiplegia are unusual. Here, we report an unusual case of prolactinoma with cerebral stroke and sparse prolactin (PRL) expression. A 25-year-old woman complaining of amenorrhea, dysphasia, and left hemiplegia presented with serum PRL level in excess of 4,700 ng/ml. Pre-operational radiology images revealed a giant macroadenoma and a thalamic infarct due to carotid compression. Transcranial surgery was performed. IHC study of the adenoma revealed no hormonal expression other than sparse PRL immunoreactivity. Therefore, a sparsely granulated PRL cell adenoma was diagnosed. The patient is still under follow-up with continuing cabergoline treatment.


2021 ◽  
Vol 185 (3) ◽  
pp. G1-G33
Author(s):  
A Luger ◽  
L H A Broersen ◽  
N R Biermasz ◽  
B M K Biller ◽  
M Buchfelder ◽  
...  

Pregnancies are rare in women with pituitary adenomas, which may relate to hormone excess from secretory subtypes such as prolactinomas or corticotroph adenomas. Decreased fertility may also result from pituitary hormone deficiencies due to compression of the gland by large tumours and/or surgical or radiation treatment of the lesion. Counselling premenopausal women with pituitary adenomas about their chance of conceiving spontaneously or with assisted reproductive technology, and the optimal pre-conception treatment, should start at the time of initial diagnosis. The normal physiological changes during pregnancy need to be considered when interpreting endocrine tests in women with pituitary adenomas. Dose adjustments in hormone substitution therapies may be needed across the trimesters. When medical therapy is used for pituitary hormone excess, consideration should be given to the known efficacy and safety data specific to pregnant women for each therapeutic option. In healthy women, pituitary gland size increases during pregnancy. Since some pituitary adenomas also enlarge during pregnancy, there is a risk of visual impairment, especially in women with macroadenomas or tumours near the optic chiasm. Pituitary apoplexy represents a rare acute complication of adenomas requiring surveillance, with surgical intervention needed in some cases. This guideline describes the choice and timing of diagnostic tests and treatments from the pre-conception stage until after delivery, taking into account adenoma size, location and endocrine activity. In most cases, pregnant women with pituitary adenomas should be managed by a multidisciplinary team in a centre specialised in the treatment of such tumours.


Author(s):  
Sylvia L. Asa ◽  
Kalman Kovacs

ABSTRACT:Clinically non-functioning pituitary adenomas are morphologically classified into two groups, those which have hormone immunoreactivity and ultrastructural features of known adenohypophysial cell types but are clinically silent, and those composed of cells that do not resemble nontumorous adenohypophysial cell types. Among the fomer are the silent somatotroph adenomas, silent corticotroph adenomas and silent gonadotroph adenomas; the latter include the silent type III adenomas, null cell adenomas and oncocytomas. We review their histological, immunohistochemical and ultrastructural features, the results of in situ hybridization to determine hormone synthesis by these tumors and data obtained from tissue culture characterizing their hormone release in vitro. Non-functioning adenomas represent a heterogeneous group. The discrepancies between morphology, immunoreactivity and lack of endocrine activity of silent adenomas are not clear. Oncocytomas are variants of null cell adenomas. We suggest that null cell adenomas and oncocytomas originate in uncommitted pluripotent precursor cells capable of undergoing multidirectional differentiation. The progenitor cells differentiate most frequently toward FSH / a-subunit producing cells; the mechanism of preferential differentiation is obscure.


Author(s):  
D. J. McComb ◽  
J. Beri ◽  
F. Zak ◽  
K. Kovacs

Investigation of the spontaneous pituitary adenomas in rat have been limited mainly to light microscopic study. Furth et al. (1973) described them as chromophobic, secreting prolactin. Kovacs et al. (1977) in an ul trastructural investigation of adenomas of old female Long-Evans rats, found that they were composed of prolactin cells. Berkvens et al. (1980) using immunocytochemistry at the light microscopic level, demonstrated that some spontaneous tumors of old Wistar rats could contain GH, TSH or ACTH as well as PRL.


Author(s):  
R.C. Caughey ◽  
U.P. Kalyan-Raman

Prolactin producing pituitary adenomas are ultrastructurally characterized by secretory granules varying in size (150-300nm), abundance of endoplasmic reticulum, and misplaced exocytosis. They are also subclassified as sparsely or densely granulated according to the amount of granules present. The hormone levels in men and women vary, being higher in men; so also the symptoms vary between both sexes. In order to understand this variation, we studied 21 prolactin producing pituitary adenomas by transmission electron microscope. This was out of a total of 80 pituitary adenomas. There were 6 men and 15 women in this group of 21 prolactinomas.All of the pituitary adenomas were fixed in 2.5% glutaraldehyde, rinsed in Millonig's phosphate buffer, and post fixed with 1% osmium tetroxide. They were then en bloc stained with 0.5% uranyl acetate, rinsed with Walpole's non-phosphate buffer, dehydrated with graded series of ethanols and embedded with Epon 812 epoxy resin.


Author(s):  
S. Jalalah ◽  
K. Kovacs ◽  
E. Horvath

Lactotrophs, as many other endocrine cells, change their morphology in response to factors influencing their secretory activity. Secretion of prolactin (PRL) from lactotrophs, like that of other anterior pituitary hormones, is under the control of the hypothalamus. Unlike most anterior pituitary hormones, PRL has no apparent target gland which could modulate the endocrine activity of lactotrophs. It is generally agreed that PRL regulates its own release from lactotrophs via the short loop negative feedback mechanism exerted at the level of the hypothalamus or the pituitary. Accordingly, ultrastructural morphology of lactotrophs is not constant; it is changing in response to high PRL levels showing signs of suppressed hormone synthesis and secretion.By transmission electron microscopy and morphometry, we have studied the morphology of lactotrophs in nontumorous (NT) portions of 7 human pituitaries containing PRL-secreting adenoma; these lactotrophs were exposed to abnormally high PRL levels.


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