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Query: UMLS:C0027651 (tumor)
 685,946 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A pituitary adenoma was removed transsphenoidally from a 20-yr-old woman with secondary amenorrhea, galactorrhea, and hyperprolactinemia. Light and electronic microscopy, immunocytology characterized a prolactin cell tumor. The patient also underwent three surgical explorations for hyperparathyroidism. Only after selective catheterization of thyroid veins with radioimmunoassay for parathormone, an intrathyroidal parathyroid adenoma was found. No other case of proven prolactin adenoma in Wermer's syndrome has been reported.
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PMID:[Endocrine polyadenomatosis associated with prolactin pituitary adenoma and an intrathyroidal parathyroid adenoma]. 1 58

Light and electron microscopical examination of a pituitary adenoma showed that the tumor was composed of prolactin cells that produced amyloid-like material. The findings have been interpreted in favor of the role of rough endoplasmic reticulum in amyloid fibril formation within the adenoma cells. Histochemical and fine structural data indicate that the material produced by this tumor resembles apudamyloid rather than immunoamyloid.
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PMID:Pituitary adenoma producing amyloid-like substance. 5 61

Electron microscopy revealed the presence of intracisternal virus-like particles in a mixed pituitary adenoma consisting of growth hormone cells and prolactin cells. The tumor was removed by surgery from a 48 year old man with a multiple endocrine adenomatosis type I syndrome. The significance of virus-like particles in the pathogenesis of pituitary adenomas remains to be elucidated.
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PMID:Intracisternal virus-like particles in a human pituitary adenoma. 13 Jul 39

A pituitary adenoma with suprasellar extension that had caused hyperthyroidism due to secretion of excess thyrotropin (TSH), as well as mild hyperprolactinemia, was studied with differential staining, immunocytochemistry and electron microscopy. Most cells of the tumor strained lightly with aldehyde thionin, which demonstrates the granules of normal thyrotrops, and immunocytochemically with antiserum to the hormone-specific beta chain of TSH. A minority of the cells was immunoreactive for prolactin. Electron microscopy revealed light cells interspersed with highly pleomorphic dark cells. Both were sometimes multinucleated, and contained variable numbers of small secretion granules, multiple Golgi complexes, and abundant endoplasmic reticulum.
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PMID:Pituitary adenoma producing thyrotropin and prolactin. An immunocytochemical and electron microscopic study. 14 21

Electron microscopy of an amphophil pituitary adenoma surgically removed from a 51-year-old woman who had Nelson's syndrome revealed that the tumor was composed of melanocorticotroph cells. This finding is consistent with the view that in the human pituitary gland one single cell type produces both adrenocorticotropic hormone (ACTH) and melanocyte-stimulating hormone (MSH). In contrast to the ultrastructure of pituitary adenomas associated with Cushing's syndrome, no or only very few microfilaments were detected in the cytoplasm of the tumor cells, suggesting that adrenocortical steroids are required for the formation of microfilaments. The presence or absence of microfilaments in the tumor cells may be regarded as a distinguishing ultrastructural feature between Cushing's syndrome and Nelson's syndrome. It appears that changes in the level of circulating corticoids may affect the ultrastructural features of melanocorticotroph cells not only in normal pituitaries but also in adenohypophyseal adenomas.
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PMID:Light and electron microscopic features of a pituitary adenoma in Nelson's syndrome. 17 83

A chromophobic pituitary adenoma induced on BD IX-rats has been grafted on animals of the same strain. The transplanted tumour takes in 90-100%; it grows at a slow rate (in 7 months after grafting a weight of 7-20 g is attained). Tumour-bearing animals display gigantism and hypertrophy of adrenals; moreover, in 33% of cases, diabetes is observed. With non-diabetic animals, splenomegaly and marked leukocytosis are observed; immature white and red cells are present in the peripheral blood. Spontaneous regression of the tumour never occurs. After surgical removal, tumour regrowth and the formation of metastases are observed. Diabetes is characterised by pronounced hyperglycaemia, glucosuria, polyphagia and polydipsia. Histochemically, insulin cannot be detected in pancreas. Splenomegaly is never observed in diabetic animals. Transplanted adenoma frequently tends to stop growing. No recurrence is observable after extirpation. Spontaneous regression of the tumour sometimes occurs. Gigantism, hypertrophy of adrenals and diabetes are considered as consequences of growth hormone- and ACTH-secretion of the transplanted adenoma. At present the tumour is running in the 8th passage. It did not change its characteristics over a period of 5 years.
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PMID:Transplantable, STH-producing and diabetogenic pituitary adenoma of the BD IX-strain of rats. 17 13

Tubular inclusions were present in 13 out of 43 pituitary adenomas of acromegalic patients and in a single chromophobe pituitary adenoma. There were none in 76 other pituitary adenomas with differing endocrinological symptomatology. The arrays were usually located in the perinuclear cistern of capillary endothelial cells. The tubule diameter in osmium fixed material measured 19-26 nm and the light core averaged 6-11 nm. A longitudinal period of about 4.5 nm could be demonstrated with PTA block staining. Fixation with glutaraldehyde and block staining with ethidium bromide as well as permanganate fixation followed by RNAse treatment showed only the core of the tubules consisting of globular subunits. Several histochemical reactions (perchloric acid extraction, methenamine-silver staining, trypsin and DNAse digestion of frozen sections) suggested that the particles consist of a core of DNA coated with protein. No virus multiplication could be detected in cell cultures or in mice innoculated with fresh tumor material. No significant antibody titers against several virus antigens could be demonstrated.
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PMID:Ultrastructure of tubular inclusions in endothelial cells of pituitary tumors associated with acromegaly. 17 95

A retrospective ethnic study was made of 16,311 cases of primary central nervous system (CNS) tumors seen at the Armed Forces Institute of Pathology (AFIP), Washington, D.C., from 1958 to 1970. Results showed a considerably higher Caucasian:Negro (C:N) case ratio (13.7:1) than the C:N population ratio (8.4:1), indicating a higher relative frequency of primary CNS tumors in American Caucasians as compared to American Negroes. The glioma was significantly more frequent in Caucasians than in Negroes (p less than 0.005). In contrast, Negroes had an excess of the pituitary adenoma as compared to Caucasians (P less than 0.01). The proportional frequencies of the meningioma and the nerve sheath tumor were also higher in Negroes than in Caucasians. When this pattern of the tumor distribution of American Negroes was compared to that of African Negroes (a composite African series), the preponderance of the pituitary adenoma and the meningioma and the relative paucity of the glioma in the Negro race as compared to Caucasians were again confirmed. The differences in the relative frequency and the tumor distribution between American Negroes and Caucasians and the considerable similarity of the tumor distribution between American and African Negroes emphasize the importance of genetic factors in the development of at least some primary CNS tumors.
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PMID:The ethnic distribution of primary central nervous system tumors: AFIP, 1958 to 1970. 18 96

Adhesive arachnoiditis is an occasional finding during neurosurgical operations for pituitary adenoma, previously treated by radiation therapy. A case where an arachnoidal process was found in combination with an eosinophilic pituitary adenoma, which had never been treated by irradiation, is reported. A 44-year-old woman at the time of surgery with scarce endocrinologic symptoms had suffered visual loss from 2 episodes, 18 years apart. Analysis of her symptoms, neuro-ophthalmologic findings and neurodadiologic features suggest that her visual damage was due to an optochiasmatic arachnoiditis, rather than to the tumor itself.
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PMID:Optochiasmatic syndrome from adhesive arachnoiditis with coexisting hypophyseal adenoma: case report. 19 21

Pituitary adenomas arise from and consist of adenohypophyseal cells. Based on the tinctorial characteristics of the cell cytoplasm, they were divided previously into chromophobic, acidophilic, and basophilic adenoma types. This classification is only of limited value, since it fails to consider the endocrine function of the adenoma cells and the cell type from which the tumor originates. Advanced morphologic techniques, including electron microscopy and immunocytology, led to a new pituitary adenoma classification reflecting current knowledge and attributing greater significance to clinical features, structure-function relationships, and cytogenesis. The morphologic study of pituitary adenomas is still in a relatively early stage and much more work is required to understand the basic principles of pituitary cytopathology. Thus, the classification used in this review may change as new facts accumulate. We feel justified to say that attempts to correlate structural features of pituitary adenomas with secretory activity and their separation into distinct entities cannot be regarded as examples of curiosity-oriented research. This type of investigation represents not only an intellectually rewarding experience, but is also of practical value and provides important information for the endocrinologists.
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PMID:Pituitary adenomas. 20 13


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