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Query: UMLS:C0001430 (adenoma)
 21,222 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Hyalinizing trabecular adenoma is a recently described benign thyroid tumor, almost exclusively occurring in females. The morphological features of this entity overlap with both papillary and medullary carcinoma to varying extent. This, in turn, creates a situation of serious diagnostic pitfall particularly for a false positive diagnosis of papillary carcinoma in fine needle aspiration (FNA) cytology. False consideration of medullary carcinoma is also possible by the unwary especially if staining for Congo red and/or immunostaining for calcitonin is not resorted to. At histologic level, the distinctive architectural pattern is however of great help and thus poses a much lesser danger of misdiagnosis. We relate here our experience in a recently encountered case of hyalinizing trabecular adenoma and describe detailed FNA cytologic and histologic findings along with immunohistochemical profile using a panel of eight monoclonal antibodies. The tumor proliferative potential has also been assessed using MIB-1 (Ki-67) immunostaining. The various pros and cons of diagnostic pitfalls are discussed.
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PMID:Hyalinizing trabecular adenoma--a case report with FNAC histologic, MIB-1 proliferative index and immunohistochemical findings. 986 13

Europeans have a high incidence of colorectal cancer in comparison to Africans. Lack of detectable sequence adenoma-colorectal carcinoma in Africans may suggest the development of adenocarcinoma is de novo. The aim of this study is to assess colonic mucosal proliferative activity in various pathological conditions of diverse population groups. Materials included routinely processed tissue specimens from consecutively resected well- and moderately differentiated colorectal adenocarcinomas from 32 rural Africans (South Africa) and 27 urban Europeans (Poland) and from apparently normal rectal mucous membrane from the age and sex matched each population group (28 and 25 samples respectively). In addition, 32 resected adenomatous polyps were examined in Europeans as well. The MIB 1 monoclonal antibody was used to assay the expression of Ki67 antigen in routinely processed tissue specimens. Proliferative activity in colonic carcinomas was scored by the percentage of positively stained cells. Labelling indices were estimated in 5 crypt compartments in apparently normal colonic mucosa adjacent and distant to the tumour, in mucosal samples of controls from both population groups and in adenomatous polyps from Europeans. The mean age of African patients with adenocarcinoma was markedly lower than in European counterparts (48.6 yrs vs. 66.4 yrs). The overall proliferative activity in cancerous tumours of Africans was higher than in Europeans. The labelling indices were lower in all compartments in normal colonic mucosa in Africans. Overall increase of the labelling indices in adjacent and distant to the tumour mucosa noted when compared to the mucosa of healthy individuals. No such differences were detected between indices in the mucosa adjacent and the mucosa distant to the tumour. Proliferative activity in the mucosa adjacent to adenoma was also higher than in normal mucosa from healthy individuals. Adenomas with marked dysplasia showed higher and diffuse proliferative activity, when regular adenomas shown superficial labelling only. Relatively young age, lack of detectable evidence of adenoma-carcinoma sequence and low proliferative activity in all compartments of mucosa from healthy individuals indicate different etiopathogenesis of colorectal carcinoma in rural Africans.
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PMID:Proliferative activity of normal and neoplastic colonic mucosa in population groups with high and low risk for colorectal carcinoma. 989 33

Activation of the angiogenic process occurs during tumorigenesis, as does disturbance of cell proliferation and apoptosis. Seeking a potential correlation, we investigated tumor cell apoptosis, proliferation, and angiogenesis in the adenoma-carcinoma sequence of colorectal carcinogenesis using an in situ apoptosis detection kit and MIB-1 and anti-CD34 antibodies in 27 adenomas with low dysplasia, 17 adenomas with high dysplasia, and 26 carcinomas in adenoma, as well as assessed p53 and bcl-2 expressions. The results showed that the potential for apoptosis was augmented, paralleling the increment of proliferation, in adenomas with low dysplasia but diminished when adenomas progressed from low dysplasia to high dysplasia and cancer. A gradual increment of microvessel density was observed during the progression with an increase during transition from low dysplasia to high dysplasia and cancer. Correlation coefficient test showed an inverse correlation between apoptotic index and microvessel density when all of the lesions were taken into account. No apparent impact of aberrant p53 on angiogenesis or bcl-2 on apoptosis was observed in this study. These results suggest that the angiogenesis initiates during transition from low dysplasia to high dysplasia and cancer, which may, in turn, contribute to the reduction of tumor cell apoptosis during colorectal carcinogenesis.
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PMID:Changes of angiogenesis and tumor cell apoptosis during colorectal carcinogenesis. 991 11

Immunohistochemical detection of cell proliferation-associated antigens was investigated in 28 cases of adenoid cystic carcinoma (ACC) and 20 cases of pleomorphic adenoma (PA), using antibodies against DNA topoisomerase type II alpha (topo-II) (Ki-S1) and Ki-67 (MIB-1). The correlation of staining indices with clinicopathological data, histological features and prognosis was also studied. The topo-II value was significantly higher in ACC than in PA (P<0.0001), and highest in the solid growth pattern of ACC. In addition, significant relationships were found between topo-II values and clinical features such as local recurrence, surgical margins, and distant metastases. By log-rank test, the topo-II index was also correlated significantly with patient survival (P<0.01). The values of topo-II index paralleled those of Ki-67 index in ACC, and a correlation coefficient of 0.97 was obtained. Topo-II may be considered an additional marker for estimating the proliferating fraction of cells and for predicting the short-term prognosis for patients with salivary gland tumors.
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PMID:Immunohistochemical detection of DNA topoisomerase type II alpha and Ki-67 in adenoid cystic carcinoma and pleomorphic adenoma of the salivary gland. 1006 42

The histologic spectrum of proliferative parathyroid lesions (hyperplasia, adenoma, and carcinoma) often overlap, and differentiation between these lesions may at times be difficult. p27kip1 (p27) is a cyclin-dependent kinase inhibitor that helps regulate the transition from the G1 to the S phase of the cell cycle. Significantly higher levels of p27 expression have been detected in some normal tissues than in their neoplastic counterparts. The authors analyzed a series of parathyroid lesions to determine if expression of this cell cycle protein may be useful in distinguishing between parathyroid hyperplasia, adenomas, and carcinomas. Formalin-fixed paraffin-embedded tissues from randomly selected patients (22 histologically normal parathyroid glands, 33 cases of hyperplasia, 43 adenomas, and 17 carcinomas) were analyzed for expression of p27 by immunostaining. All cases were also immunostained for Ki67 with antibody MIB-1. The distribution of immunoreactivity was analyzed by quantifying the percentage of positive nuclei that was expressed as the labeling index (LI). In situ hybridization (ISH) for p27 mRNA was done using a cRNA probe with 30 of these cases. Normal parathyroid glands had the highest p27 LI (89.6 +/- 1.4), followed by hyperplasia (69.6 +/- 7.5), adenomas (56.8 +/- 3.4), and carcinomas (13.9 +/- 2.6). ISH showed no differences in p27 mRNA, indicating that the expression of the p27 gene was controlled at a posttranslational level in parathyroid tissues. Ki67 expression was significantly higher in carcinomas (LI = 8.4 +/- 1.9) than in adenomas (LI = 2.7 +/- 0.2) and hyperplasia (LI = 3.3 +/- 0.4). These results suggest that both p27 and Ki67 may be helpful in the diagnosis of histologically difficult parathyroid lesions.
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PMID:Parathyroid hyperplasia, adenomas, and carcinomas: differential expression of p27Kip1 protein. 1007 19

To clarify the growth mechanisms of thyroid tumors, we examined apoptotic cells in 61 thyroid tumors, consisting of 14 adenomas, 35 papillary carcinomas, 4 follicular carcinomas, and 8 undifferentiated carcinomas, using terminal deoxynucleotidyl transferase mediated deoxyuridine triphosphate digoxigenin-nick end labeling (TUNEL). The proliferative activity was also evaluated immunohistochemically using the monoclonal antibody to Ki-67 antigen (MIB-1) in the same tumors. The apoptotic index (AI) was expressed as a percentage of the TUNEL-positive cells in the tumor cells, and a proliferation index (PI), being the percentage of Ki-67 positive cells, was calculated for each tumor. The overall level of AI was very low in all histotypes of the thyroid tumors analyzed, the mean AI being 0.5 +/- 0.4 in adenoma, 0.4 +/- 0.3 in differentiated carcinoma, and 1.8 +/- 1.5 in undifferentiated carcinoma. The PI in the thyroid tumor subtypes was significantly lower in adenoma and differentiated carcinoma, at 0.5 +/- 0.7 and 1.1 +/- 0.7, respectively, than that in undifferentiated carcinoma at 14.5 +/- 3.7 (P < 0.05). There was no correlation between clinicopathological factors and AI or PI in differentiated thyroid carcinoma. Our findings suggest that apoptosis occurs infrequently in thyroid tumors, and that proliferative activity markedly differs according to the thyroid tumor subtypes. Moreover, the ratio between proliferating cells and apoptotic cells may reflect thyroid tumor progression.
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PMID:Apoptosis and proliferative activity in thyroid tumors. 1019 28

This study investigated the combined immunoexpression of p53, p21, bcl-2, bax, Rb and Ki67 proteins in colorectal adenocarcinomas and correlated expression patterns with tumour stage and grade. Paraffin sections from 98 cases of colorectal adenocarcinomas were stained by immunohistochemistry for p53, p21, bcl-2, bax, Rb and MIB-1 (Ki67) proteins. In addition, 12 cases of colorectal adenomas and normal colorectal mucosa were studied in parallel. P53, p21, bcl-2, bax, Rb and Ki67 proteins were detected in at least 5% of tumour cells in 63/98, 72/98, 52/98, 96/98 and 98/98 adenocarcinomas, respectively. Comparative study of the normal-adenoma-carcinoma tissues revealed abrogation of the normal immunotopography in adenomas and adenocarcinomas, and considerable modifications, increase or reduction, of the expression of p53, p21, bcl-2, bax, Rb and Ki67 proteins in adenocarcinomas when compared with normal mucosa and adenomas. Statistically significant correlations were found between low bax expression and Dukes C stage of carcinomas, Ki67 expression and carcinoma grade, and Ki67 and Rb expression. P53, p21, bcl-2 and Rb immunoexpression did not correlate with tumour stage or grade. Our findings show that low bax immunoexpression is frequently related to colorectal adenocarcinomas with lymph node metastases suggesting that low levels of bax expression play a role in late stage colorectal cancer. The correlation between Ki67 and Rb expression, in view of previous data that the hyperphosphorylated inactive Rb protein is frequently increased in colorectal adenocarcinomas, suggests that Rb protein is somewhat ineffective in inhibiting the cell-cycle progression in these malignancies. Furthermore, our findings provide immunohistochemical evidence that the abrogation of the normal immunotopography and the modifications of the expression of p53, p21, bcl-2, bax, Rb and Ki67 proteins reflect important events in colorectal oncogenesis.
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PMID:Expression of p53, p21/waf, bcl-2, bax, Rb and Ki67 proteins in colorectal adenocarcinomas. 1038 39

Dysplasia in Barrett's esophagus (BE) is a precursor to adenocarcinoma and most commonly occurs as a flat, grossly undetectable lesion. Rarely, dysplasia in BE may grow as a polypoid lesion. Most BE-associated polypoid dysplastic lesions have been referred to as "adenomas" because of their histological similarity to a colonic adenoma. BE-associated polypoid dysplastic lesions have been less well characterized than the flat type. Therefore, our aim was to characterize the clinicopathologic and molecular features of five cases of BE-associated polypoid dysplasia and to review the literature on this entity. The cases were evaluated clinically, histologically, immunostained for MIB-1 and p53, and genotyped for loss of heterozygosity (LOH) at the adenomatous polyposis coli (APC) locus. Mucosal biopsy specimens of five BE patients without dysplasia, and five BE cases with high-grade flat dysplasia, were used as controls. The study patients were all male (average age, 71 years) who presented with symptoms of gastroesophageal reflux disease. Endoscopically, all five cases had a well-defined sessile or pedunculated polypoid lesion ranging from 0.4 to 1.5 cm in size in the mid (n = 1) or distal (n = 4) esophagus and were associated with specialized-type BE (four long segment, one short segment). Histologically, the polyps consisted of intestinalized epithelium with low- and high-grade dysplasia. All five cases contained adenocarcinoma (four within the polyp, one in adjacent BE). All polyps showed increased cell proliferation in the form of surface MiB-1 staining and showed positive p53 staining. Three of three (100%) informative cases showed LOH at the APC locus in the dysplastic epithelium and in areas of adenocarcinoma. All five flat dysplasia controls also showed surface MIB-1 staining and p53 positivity, and three of three informative controls showed LOH for APC. None of the nondysplastic BE controls showed any of these findings. Three patients were treated with esophagectomy and two with polypectomy. All were alive, without metastasis, from 2 months to 6 years later. A literature review of esophageal "adenomas" uncovered 12 cases. Four of these had no clinical or pathological information, two were, in fact, gastric heterotopic lesions, one was composed entirely of intestinal-type epithelium, and five were polypoid dysplastic lesions similar to the cases described here (three male, two female; mean age, 59 years). Four of these five cases were associated with adenocarcinoma in the polyp (two intramucosal, two submucosal). In summary, BE-associated polypoid dysplasia share similar clinical, pathological, and molecular features as flat dysplasia and are often associated with adenocarcinoma. Thus, we agree with other authors who recommend that the term adenoma, which usually carries a benign connotation, be abandoned in favor of a descriptive diagnostic term, such as "BE-associated polypoid dysplasia." BE patients with this lesion should be considered strong candidates for esophageal resection similar to lesions of this kind that occur in inflammatory bowel disease.
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PMID:Polypoid dysplasia in Barrett's esophagus: a clinicopathologic, immunohistochemical, and molecular study of five cases. 1041 92

In order to examine stromal-epithelial interaction during the oncogenic progression of large bowel tumors, the association between pericryptal fibroblast sheath (PCFS) and expression of Ki-67 antigen was evaluated in 87 cases of colorectal adenoma and 95 cases of carcinoma with an adenoma component (CWA). For the immunohistochemistry, anti-alpha-smooth muscle actin antibody (alpha-SMA) and anti-Ki-67 antigen antibody (MIB-1) were used. In adenomas and adenoma components of CWA, the quantity of neoplastic glands with PCFS was reduced relative to the progression of histological atypia. Pericryptal fibroblast sheath was virtually absent from invasive carcinoma areas of CWA. Increased expression of Ki-67 correlated with the degree of histological atypia of adenomas. A significant reverse correlation was also seen between Ki-67 expression and PCFS-positive glands in adenoma components of CWA. These findings suggest that the prevalence of PCFS and Ki-67 expression are important indicators of colorectal neoplasia progression. The significant reduction of PCFS in colorectal epithelial neoplasms reflects progression in the adenoma-carcinoma sequence.
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PMID:Immunohistochemical analysis of pericryptal fibroblast sheath and proliferating epithelial cells in human colorectal adenomas and carcinomas with adenoma components. 1041 86

We report a case of vesical tubulovillous adenoma that occurred in a background of protracted chronic cystitis with intestinal-type glandular metaplasia and extensive cellular atypia (dysplasia) in the flat mucosa. Flow cytometry analysis showed DNA aneuploidy in the adenoma. Increased expression of the tumor suppresser gene, p53, and also of cellular proliferation markers (proliferating cell nuclear antigen and MIB-1) were detected in the villous adenoma and in the dysplastic regions of the flat metaplastic mucosa. These findings provide insight into the biology of intestinal metaplasia and also lend support to the theory of the chronic irritation-metaplasia-dysplasia-carcinoma sequence.
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PMID:Tubulovillous adenoma of the urinary bladder. 1043 Feb 79


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