Proliferation of adenohypophyseal cells into posterior lobe (original) (raw)
Related papers
My approach to pathology of the pituitary gland
Journal of Clinical Pathology, 2006
The sellar region is the site of a large number of pathological entities arising from the pituitary and adjacent anatomical structures, including brain, blood vessels, nerves and meninges. The surgical pathology of this area requires the accurate identification of neoplastic lesions, including pituitary adenoma and carcinoma, craniopharyngioma, neurological neoplasms, germ cell tumours, haematological malignancies and metastases, as well as non-neoplastic lesions such as cysts, hyperplasias and inflammatory disorders. This review provides a practical approach to the diagnosis of pituitary specimens that are sent to the pathologist at the time of surgery. The initial examination requires routine haematoxylin and eosin staining to establish whether the lesion is a primary adenohypophysial proliferation or one of the many other pathologies that occurs in this area. The most common lesions resected surgically are pituitary adenomas. These are evaluated with several special stains and immunohistochemical markers that are now available to accurately classify these pathologies. The complex subclassification of pituitary adenomas is now recognised to reflect specific clinical features and genetic changes that predict targeted treatments for patients with pituitary disorders.
The American journal of pathology, 1989
Pituitary adenomas, removed surgically from three women with normal or slightly elevated serum growth hormone levels and no evidence of acromegaly, were studied. The tumor cells were shown by electron microscopy to correspond to sparsely granulated somatotrophs but immunocytochemistry showed that they contained no, moderate, or little growth hormone. Two tumors examined in vitro secreted small amounts of growth hormone in the tissue culture medium initially with a spontaneous rise after several days, and responded to growth hormone-releasing hormone stimulation with increased growth hormone release. In situ hybridization demonstrated growth hormone mRNA expression in adenoma cells. Clinically silent somatotroph adenomas represent a hitherto undescribed entity; electron microscopy shows that they consist of somatotrophs, and express growth hormone mRNA but do not secrete growth hormone in amounts needed to raise substantially serum growth hormone levels and cause acromegaly. Further ...
Clinically Non-Functioning Human Pituitary Adenomas
Canadian Journal of Neurological Sciences / Journal Canadien des Sciences Neurologiques, 1992
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 aden...
Pituitary adenomas immunocytochemical study of 150 tumors with clinicopathologic correlation
Cancer, 1983
Retrospective immunocytochemical study of prolactin, growth hormone, ACTH, TSH and gonadotropins was performed on 150 pituitary adenomas from 142 patients and the results were correlated with clinical manifestations. There were 60 prolactin-positive tumors, 13 growth hormone-positive tumors, nine ACTH-positive tumors and seven gonadotropin-positive tumors. Seven tumors showed positivity for both prolactin and growth hormone, one tumor was positive for prolactin and ACTH and another was positive for prolactin and TSH. Fifty-two tumors were negative for all the hormones. In the hormone secreting tumors, the results of immunocytochemical study correlated very well with clinical manifestations, while most of the hormone-negative tumors were nonfunctioning clinically. This study demonstrates the reliability of the immunocytochemical method in clinicopathologic study of pituitary adenomas. Cancer 52:648-653, 1983. ITUITARY ADENOMAS have long been classified ac-P cording to their tinctorial quality as acidophil. basophil, or chromophobe.'.* Acidophil adenomas were traditionally associated with acromegaly, basophil adenomas with Cushing's syndrome, and chromophobe adenomas were thought to be nonfunctioning. However, it has become obvious that this classification is inadequate to cover the diverse clinicopathologic spectrum of pituitary a d e n o m a~.~ Recent developments in immunocytochemical techniques make it possible to specifically demonstrate various hormones in normal or neoplastic anterior pituitary Since paraffin sections of formalin fixed tissue are compatible with the newly developed immunoperoxidase methods, retrospective studies are now possible.' This study was conducted to assess the value and reliability of the immunoperoxidase method in clinicopathologic studies of pituitary adenomas.
Plurihormonal cells of normal anterior pituitary. Facts and con-clusions
Oncotarget, 2017
Introduction. plurihormonality of pituitary adenomas is an ability of adenoma cells to produce more than one hormone. After the immunohistochemical analysis had become a routine part of the morphological study, a great number of adenomas appeared to be multihormonal in actual practice. We hypothesize that the same cells of a normal pituitary gland releases several hormones simultaneously. Objective. To analyse a possible co-expression of hormones by the cells of the normal anterior pituitary of adult humans in autopsy material. Materials and methods. We studied 10 pituitary glands of 4 women and 6 men with cardiovascular and oncological diseases. Double staining immunohistochemistry using 11 hormone combinations was performed in all the cases. These combinations were: prolactin/thyroid-stimulating hormone (TSH), prolactin/luteinizing hormone (LH), prolactin/follicle-stimulating hormone (FSH), prolactin/adrenocorticotropic hormone (ACTH), growth hormone (GH)/TSH, GH/LH, GH/FSH, GH/ACTH, TSH/LH, TSH/FSH, TSH/ACTH. Laser Confocal Scanning Microscopy with a mixture of primary antibodies was performed in 2 cases. These mixtures were ACTH/prolactin, FSH/ prolactin, TSH/prolactin, ACTH/GH, and FSH/GH. Results. We found that the same cells of the normal adenohypophysis can coexpress prolactin with ACTH, TSH, FSH, LH; GH with ACTH, TSH, FSH, LH, and TSH with ACTH, FSH, LH. The comparison of the average co-expression coefficients of prolactin, GH and TSH with other hormones showed that the TSH co-expression coefficient was significantly the least (9,5±6,9%; 9,6±7,8%; 1,0±1,3% correspondingly). Conclusion. Plurihormonality of normal adenohypophysis is an actually existing phenomenon. Identification of different hormones in pituitary adenomas enables to find new ways to improve both diagnostic process and targeted treatment.
Plurihormonality of pituitary adenomas in light of immunohistochemical studies
Endokrynologia Polska
Plurihormonality of pituitary adenomas can be defined as the ability of an adenoma to express more than one pituitary hormone. The application of immunohistochemistry to diagnose surgically removed pituitary tumours revealed that a great number of pituitary adenomas are in fact plurihormonal. However, data on the incidence and the clinical relevance of the pituitary adenoma plurihormonality are still scarce and controversial. Hundred fifty-five pituitary adenomas, surgically removed, were studied immunohistochemically with the antibodies against pituitary hormones or their subunits. Additionally, 40 adenomas were immunostained with Ki-67 antibody to evaluate the proliferative potential. According to the World Health Organization (WHO) recommendations, we did not consider tumours expressing both FSH and LH (gonadotropinomas) or somatoprolactinomas expressing both GH and prolactin as plurihormonal. Even with this limitation, plurihormonality was found to be a frequent finding in both ...
Neuropathology of Pituitary Adenomas and Sellar Lesions
Neurosurgery
The pituitary gland is the site of numerous neoplastic and inflammatory processes. The overwhelmingly most frequent tumors arise from cells of the anterior lobe, the pituitary neuroendocrine tumors (PitNETs). Immunohistochemistry assay staining for pituitary hormones is the core tool for classifying PitNETs, resulting in the diagnosis of somatotroph PitNETs, lactotroph PitNETs, and so on. For cases showing no hormonal expression, the updated WHO classification system now considers the assessment of several transcription factors: PIT-1 (pituitary-specific POU-class homeodomain transcription factor); T-PIT (T-box family member TBX19); and SF-1 (steroidogenic factor regulating gonadotroph cell differentiation) before rendering a diagnosis of null cell adenoma. Other tumors and disease processes of this site often mimic PitNETs radiographically and sometimes even clinically (ie, compression of the optic chiasm). These potpourri of processes include germ cell neoplasms (especially germin...