Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0001430 (adenoma)
 21,222 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Cyclooxygenase-2 (COX-2) is one of the important targets for the chemoprevention of colorectal cancer by non-steroidal anti-inflammatory drugs (NSAIDs). To evaluate the role of COX-2 in early stages of colorectal tumorigenesis, we immunohistochemically investigated the frequency and localization of COX-2 in sporadic colorectal polyps that showed various histology using a commercially available monoclonal antibody. A total of 105 colorectal polyps were examined. These included 33 low-grade adenomas (LGAs), 28 high-grade adenomas (HGAs), 32 HGAs with p53 overexpression (HGAs-p53), and 12 cases of carcinoma in adenoma (CIA). Regarding the immunohistochemical expression of p53, MIB-1, and CD63, histological classification was made for each case. COX-2 was expressed in neoplastic epithelial cells and interstitial macrophages that were distributed mainly in the superficial areas of polyps. COX-2 labeling indices (LIs) were 8.2% in LGAs, 6.3% in HGAs, 0.9% in HGAs-p53, and 0.6% in the carcinomatous components of CIAs. COX-2 LIs were significantly higher in adenomas, including LGAs and HGAs, than in HGAs-p53 and CIAs (p < 0.001). Within CIAs, significantly higher COX-2 LIs were obtained in the adenomatous components than in the carcinomatous components (p < 0.05). The size of polyps was not correlated with COX-2 expression irrespective of their histology. The results show that COX-2 might be involved in early stages of colorectal tumorigenesis. Colorectal adenomas could be a target for the chemopreventive strategy irrespective of their sizes.
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PMID:Cyclooxygenase-2 in sporadic colorectal polyps: immunohistochemical study and its importance in the early stages of colorectal tumorigenesis. 1613 48

MAP-2, a well characterized member of the microtubule associated protein (MAP) family, binds to and stabilizes microtubules and is involved in cell proliferation as well as neuronal differentiation. The aim of the present work was to study MAP-2 expression in human adenohypophyses and pituitary adenomas. To our knowledge, data regarding MAP-2 expression in human pituitaries has not been reported to date. For immunohistochemistry, the streptavidin-biotin-peroxidase complex method was used. Nine non-tumorous adenohypophyses and 77 adenomas (GH-, PRL-, ACTH-, TSH-, FSH/LH- and/or alpha subunit- producing or immunonegative tumors) were investigated. The results show that MAP-2 is expressed in the cytoplasm of non-tumorous adenohypophysial cells as well as of various pituitary adenoma types. No significant correlation was found between MAP-2 expression and gender, patient age, mitotic activity, MIB-1 labelling indices, hormone immunoprofile, and endocrine status, ie. hormonal activity or lack thereof. Thus MAP-2 expression cannot be used to estimate cell proliferation rate, growth potential, endocrine activity or biologic behaviour of an adenoma. Immunopositivity appeared to be stronger in the cytoplasm of adenoma cells than in that of non-tumorous adenohypophysial cells, implying that the adenoma cells contain larger quantities of MAP-2. It can be concluded that the functional activity of MAP-2 is not associated with the manufacture of any specific adenohypophysial hormone(s) and is not limited to one specific cell type.
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PMID:MAP-2 expression in the human adenohypophysis and in pituitary adenomas. An immunohistochemical study. 1619 80

Silent corticotroph adenomas (SCA) are rare pituitary tumors with histologic hallmarks of corticotroph differentiation, including ACTH immunoreactivity, but lacking clinical evidence of Cushing's syndrome. We report on four female patients, aged 19-66 years, each presenting with a nonfunctional macroadenoma. Leading symptoms were headache in two cases and visual field deficits in one. One patient was incidentally diagnosed while undergoing cranial MRI for an unrelated condition. Three patients had marked obesity; none of them presented constitutional signs of Cushing's syndrome. Serum cortisol levels were moderately elevated in the two patients systematically tested in this respect. Marginal to moderate hyperprolactinemia was present in two cases. Two patients also were shown to be deficient in either gonadotroph or thyrotroph axis, while a third had a combined insufficiency of both gonadotroph and thyrotroph axis. MRI scans revealed intratumoral hemorrhage and/or cystic change in three cases, as well as tumor-related occlusive hydrocephalus in one. The latter patient was biopsied only, while the remaining underwent gross total resection. Histologically, all four lesions were diagnosed as SCA subtype I displaying intense immunoreactivity for ACTH. In three tumors, scattered cells coexpressed PRL as well. In addition, Crooke's hyaline change was noted in a significant number of tumor cells and in residual non-neoplastic corticotrophs in one case each. With MIB-1 labeling indices of 1-3%, none of the tumors qualified as atypical adenoma. We conclude that SCAs are more likely to be discovered as expansile tumors, whose advanced local space-occupying character at surgery rather than an inherently aggressive growth potential may negatively influence the clinical outcome. Subtle morphologic evidence of corticotroph suppression in residual pituitary adjacent to tumor lends further support to literature data indicating minimal or intermittent functional activity in this tumor type.
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PMID:Clinicopathologic correlations of silent corticotroph adenomas of the pituitary: report of four cases and literature review. 1649 45

We describe a hitherto undocumented variant of dimorphic pituitary neoplasm composed of an admixture of neurosecretory cells and profuse leiomyomatous stroma around intratumoral vessels. Radiologically perceived as a macroadenoma of 3.8 cm in diameter, this pituitary mass developed in an otherwise healthy 43-year-old female. At the term of a yearlong history of amenorrhea and progressive bitemporal visual loss, subtotal resection was performed via transsphenoidal microsurgery. Discounting mild hyperprolactinemia, there was no evidence of excess hormone production. Histologically, solid sheets, nests and cords of epithelial-looking, yet cytokeratin-negative cells were seen growing in a richly vascularized stroma of spindle cells. While strong immunoreactivity for NCAM, Synaptophysin and Chromogranin-A was detected in the former, the latter showed both morphological and immunophenotypic hallmarks of smooth muscle, being positive for vimentin, muscle actin and smooth muscle actin. Architectural patterns varied from monomorphous stroma-dominant zones through biphasic neuroendocrine-leiomyomatous areas, to pseudopapillary fronds along vascular cores. Only endothelia were labeled with CD34. Staining for S100 protein and GFAP, characteristics of sustentacular cells, as well as bcl-2 and c-kit was absent. Except for alpha-subunit, anterior pituitary hormones tested negative in tumor cells, as did a panel of peripheral endocrine markers, including serotonin, somatostatin, calcitonin, parathormone and vasoactive intestinal polypeptide. Mitotic activity was absent and the MIB-1 labeling index low (1-2%). While assignment of this lesion to any established neoplastic entity is not forthcoming, we propose it is being considered as a low-grade neuroendocrine tumor possibly related to null cell adenoma.
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PMID:Leiomyomatoid angiomatous neuroendocrine tumor (LANT) of the pituitary: a distinctive biphasic neoplasm with primitive secretory phenotype and smooth muscle-rich stroma. 1652 Sep 66

Spindle cell metaplasia in thyroid adenoma or carcinoma is rare and its pathological features are not well characterized. Distinction of this entity from medullary or anaplastic carcinoma has an important clinical implication. We encountered a case of thyroid follicular adenoma associated with spindle cell metaplasia. It showed "tumor in tumor appearance" and neoplastic spindle cells were positive for thyroglobulin, thyroid transcription factor-1, vimentin and focally chromogranin A and somatostatin (SS). MIB-1 index was <1%. Ultrastructure of the spindle cells was reminiscent of follicular cell origin. From the findings from our case, spindle cell metaplasia appears to be a benign clinical entity, suggestive of multidirectional differentiation of follicular cells.
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PMID:Spindle cell metaplasia arising in thyroid adenoma: characterization of its pathology and differential diagnosis. 1661 Feb 45

In the study authors tried to estimate the diagnostic value ofAgNOR number and MIB-1 and PCNA expression in thyreocytes from various pathological lesions, with special attention to differential diagnosis of border-line lesions (nodule in adenomatus goiter--adenoma--follicular carcinoma). Fifty four thyroid glands were examined (10 adenomatous goiters, 20 follicular adenomas, 10 follicular carcinomas, 14 papillary carcinomas). Statistical analysis of obtained results allows in most cases to differentiate carcinomas from benign nodular lesions. The best differentiating factor for border-line lesions (especially differentiation between benign nodular lesions, neoplasms, nodules in adenomatous goiter adenomas and adenomas carcinomas) has turned out to be MIB-1. PCNA expression has differed significant between adenomatous goiter and follicular carcinoma and between adenoma and both carcinomas. AgNOR number has only helped in differentiation between nodules in adenomatous goiter and follicular carcinoma - correlations for other lesions have not been statistically significant.
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PMID:[Practical application of proliferation markers' (MIB-1, PCNA, AgNOR) expression analysis for differential diagnostics of nodular thyroid lesions]. 1664 89

Herein, we report the case of a 46-year-old male patient with only one month of double vision. Radiological examination revealed a pituitary tumor. Endocrinological investigations showed no pathological alterations of anterior pituitary function. Neuropathological examinations revealed a pituitary gland adenoma with an elevated proliferation rate (MIB-1 index 4-5 %) as well as an elevated p53 expression leading to the diagnosis of an atypical pituitary adenoma. Interestingly, the tumor exhibited strong basophilia in routine histology and densely secretory granules in electron microscopy (EM). However, no hormone excess was detectable in immunohistochemistry. In contrast to clinical and immunohistochemical observations, EM and routine histology findings implied a hormone production. This discrepancy might be due to a production of unfunctional pre-stages of pituitary gland proteins in this fast growing neoplasm.
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PMID:Atypical pituitary adenoma exhibiting densely secretory granules and basophilia without hormone production. 1664 9

Herein, we report the case of a 28-year old woman clinically presenting with unclear weight gain over the last years. The patient displayed facial and neck edema in combination with unobtrusive striae distensae. Endocrinological examinations led to the diagnosis of Cushing's disease. Neuroradiological examination revealed an intrasellar tumor mass of 7 mm in diameter. Subsequently, transsphenoidal tumor resection was performed. Histological and immunohistochemical investigations revealed a pituitary gland adenoma showing a biphasic tumor growth pattern with two morphologically different tumor areas producing ACTH and prolactin respectively. Co-expression of ACTH and prolactin is exceedingly rare in pituitary adenoma. To our surprise, both tumor areas exhibited features of atypia consisting in elevated MIB-1 proliferation index in the ACTH-producing portion as well as p53 expression selectively in the prolactin-producing tumor parts. To our knowledge, this is the first case of an ACTH- and prolactin-producing pituitary gland adenoma exhibiting biphasic features of atypia.
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PMID:ACTH- and prolactin-producing pituitary gland microadenoma with biphasic features of atypia and intermediate filament expression. 1664 16

Tumours of the gastrointestinal (GI) tract, of which 70% arise in the colorectum, are a major cause of morbidity and mortality worldwide. Transformation from normal to malignant mucosa is a multistep process involving specific gene mutations and is called the adenoma-carcinoma sequence. Histologically, adenomas are of three types (tubular, tubulovillous and villous) and the extent of mucosal cellular abnormality of three grades (mild, moderate and severe). Cellular proliferation is a marker of malignant potential in many tissues. In the colon, cellular proliferation is partly controlled by the CDX-2 gene, a homeobox gene expressed in differentiated cells of the intestine that has proto-oncogenic potential in murine models. In the stomach, CDX-2 is expressed in intestinal metaplasia and decreasing expression through tumourogenesis shows its tumour suppressor potential. Down-regulation in colorectal cancer cell lines is also observed. This is a retrospective study of colorectal adenomas, and haematoxylin and eosin (H&E) and immunocytochemical staining for CDX-2 and MIB-1 (a cell proliferation marker) are performed on each case. Comment is made on the morphological features (adenoma type and dysplasia severity) and the grade of CDX-2 and MIB-1 expression. This study showed that dysplasia severity is linked to cellular proliferation (P=0.011) but adenoma type was not (P=0.54). CDX-2 was not linked to the morphological features discussed (P=0.11 and P=0.16) and CDX-2 and MIB-1 expression showed no correlation. Increased cell proliferation (MIB-1 expression) was seen in increasingly dysplastic adenomatous lesions of the colorectum. CDX-2 had no link to morphological features or cell proliferation of the dysplastic mucosa.
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PMID:CDX-2 and MIB-1 expression in the colorectum: correlation with morphological features of adenomatous lesions. 1687 98

Composite adenoma-carcinoid tumors are rare colorectal lesions consisting of intermingled adenomatous and carcinoid components. Unlike other mixed endocrine-glandular colorectal neoplasms, which are generally malignant, their glandular component is histologically benign and their natural history is favorable. We present 4 cases of colonic adenomas containing microcarcinoids, a hitherto undescribed lesion that is either a precursor of composite adenoma-carcinoids or a related but independent entity. The cases, identified among our surgical and consultation files, were endoscopically routine sessile polyps removed from 4 otherwise normal individuals, 3 from the cecum and 1 from the distal colon. The microcarcinoids were 0.5 to 1.5 mm in size and situated within the basal lamina propria, where they interposed between the crypts and muscularis mucosae without disturbing the overall polyp architecture. Histologically, they consisted of collections of low-grade epithelial cells arranged in nests, cords, tubules, and irregular clusters and characterized by eosinophilic, granular, or clear cytoplasm and by round central nuclei with stippled or dusty chromatin. Endocrine differentiation of the microcarcinoids was confirmed by the expression of 3 or more of the following: Grimelius argyrophil, chromogranin, synaptophysin, neuron-specific enolase and somatostatin. No mitotic figures or MIB-1 or p53 positivity were observed. The glandular component of the polyps was unremarkable in 3 cases, but 1 polyp, in addition to a microcarcinoid, showed a diffuse pattern of mixed adenomatous-endocrine differentiation. The patients' clinical course was benign on the basis of 2 years' median follow-up (range, 6 mo to 10 y). Two patients with incomplete polypectomies underwent hemicolectomy revealing no residual endocrine neoplasia. Awareness of microcarcinoids in colonic adenomas should help avert potential diagnostic pitfalls posed by their pleomorphism, basal location, and infiltrative patterns, and may help clarify their natural history and possible relationship to composite glandular-carcinoid tumors.
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PMID:Microcarcinoids in large intestinal adenomas. 1712 8


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