1/10. Prolactin-producing pituitary adenoma and carcinoma with neuronal components--a metaplastic lesion.Recent studies indicate that cells of various epithelial tumors are capable of transformation to neurons. Observing both neurons and neuropil in two prolactin-producing adenohypophyseal tumors, one benign and one malignant, we sought to assess their cellular differentiation, the presence of nerve growth factor receptor, and expression of the dopamine receptor gene using immunocytochemistry, electron microscopy, and in situ hybridization. light and electron microscopy clearly revealed cells morphologically transitional between adenoma/carcinoma cells and neurons. Large neurons lacked proliferative activity. neurons in varying number showed immunoreactivity for pituitary hormones including prolactin, growth hormone and alpha subunit in the adenoma and prolactin alone in the carcinoma. The distribution of nerve growth factor receptor staining was similar. In both tumors, in situ hybridization showed mRNAs for prolactin and dopamine receptor within adenohypophyseal cells and neurons. Our results indicate that the occurrence of neurons and neuropil in growth hormone and prolactin-producing pituitary tumors appears to be the result of metaplasia. The process is not limited to benign tumors and may be due to the production of tropic substances by the adenohypophysial cells, which by paracrine/autocrine mechanisms result in transformation of adenoma cells to nerve cells.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
2/10. Expression of Cdx1 and Cdx2 mRNAs and relevance of this expression to differentiation in human gastrointestinal mucosa--with special emphasis on participation in intestinal metaplasia of the human stomach.BACKGROUND: The caudal-type homeobox genes, Cdx1 and Cdx2, are candidates for directing intestinal development, differentiation, and maintenance of the intestinal phenotype. The aims of this study were: (1) to assess the normal tissue expression patterns of Cdx1 and Cdx2 in the human gastrointestinal tract and (2) to ascertain levels in intestinal metaplasia (IM) of the stomach associated with gastritis. methods: Fresh human tissues were collected by surgical resection from 39 patients after informed consent had been received. RNAs were extracted from 11 distinct sites in the gastrointestinal mucosa (gastric body, gastric antrum, duodenum, jejunum, ileum, cecum, ascending colon, transverse colon, descending colon, sigmoid colon, and rectum), and Northern hybridization was performed for Cdr1 and Cdx2 mRNAs. In addition, RNAs were also extracted from normal gastric mucosa, and gastric mucosa with mild to severe IM, confirmed histopathologically. Reverse-transcriptase polymerase chain reaction (RT-PCR) was then carried out for Cdx1 and Cdx2. RESULTS: The expression of Cdx1 mRNA increased gradually from the duodenum to the distal colon, with no expression detected in the stomach. Compared with the distribution of Cdx1 mRNA in the mouse gastrointestinal tract, the expression of Cdr1 mRNA in the human gastrointestinal tract showed greater predominance in the jejunum and ileum. The expression of Cdx2 mRNA increased gradually from the duodenum to the proximal colon and decreased from the ascending colon to the rectum. Compared with the expression pattern of Cdx2 mRNA in the mouse gastrointestinal tract, the expression of Cdx2 mRNA in the human gastrointestinal tract showed greater predominance in the ileum. By RT-PCR, both Cdx1 and Cdx2 mRNAs were detected in the mild and severe types of IM. However, neither of these mRNAs was identified in normal gastric mucosa without IM. CONCLUSIONS: Cdr1 and Cdx2 mRNAs are widely present in the human intestinal and colonic mucosae, but not in the gastric mucosa, suggesting that their expression may contribute to the intestinal phenotype. The high levels of these mRNAs in IM mucosa associated with chronic atrophic gastritis point to an association with this phenotypic shift in the gastric mucosa.- - - - - - - - - - ranking = 0.5keywords = hybridization (Clic here for more details about this article) |
3/10. Combined sellar fibrosarcoma and prolactinoma with neuronal metaplasia: report of a case unassociated with radiotherapy.We report the occurrence of a primary pituitary fibrosarcoma causally unrelated to radiotherapy, admixed in association with a prolactin cell pituitary adenoma showing neuronal metaplasia. These unique findings were associated with multiple endocrine neoplasia type 1 (MEN 1). Primary fibrosarcoma involving the sella is a very rare tumor. The majority of cases have been associated with prior irradiation of either a pituitary adenoma or a craniopharyngioma. Pituitary adenoma with neuronal metaplasia is also rare and usually occurs in the setting of acromegaly. Despite the intimate association of both elements in our lesion, no transition of adenoma to sarcoma was demonstrable by immunohistochemistry or in situ hybridization studies.- - - - - - - - - - ranking = 0.5keywords = hybridization (Clic here for more details about this article) |
4/10. Human papillomavirus-associated plantar epidermoid cyst related to epidermoid metaplasia of the eccrine duct epithelium: a combined histological, immunohistochemical, dna-dna in situ hybridization and three-dimensional reconstruction analysis.BACKGROUND: We recently proposed that certain palmoplantar epidermoid cysts may be related to eccrine ducts and that human papillomavirus (HPV) 60 may play a role in their pathomechanism. However, the origin of palmoplantar epidermoid cysts is still controversial. OBJECTIVES: To examine the contribution of eccrine ducts and HPV 60 in the development of epidermoid cysts. methods: Five epidermoid cysts and four ridged warts that had developed on the soles of a patient were studied histologically, immunohistochemically and by dna-dna in situ hybridization. Using serial sections obtained from its entire body, a three-dimensional reconstruction (3DR) analysis was performed on the smallest cyst to analyse the relationship between the epidermoid cyst, eccrine duct and the overlying epidermis. RESULTS: Histological and dna-dna in situ hybridization analyses demonstrated both homogeneous intracytoplasmic inclusion bodies pathognomonic for HPV 60 infection and HPV 60 dna sequences not only in all of the epidermoid cysts and ridged warts but also in the acrosyringeal portion of an eccrine duct, with the dermal portion of which the smallest cyst had been revealed to connect by 3DR analysis. However, immunohistochemical analyses using antibodies against human carcinoembryonic antigen (CEA), involucrin and several cytokeratins (CKs) revealed that the immunoreactivity of the cyst was not identical to that of the eccrine dermal duct but was identical to that of suprabasal layers of the epidermis. CONCLUSIONS: It was clearly demonstrated that an HPV 60-associated epidermoid cyst with immunoreactivities for CEA, involucrin and CKs which were identical to those of the epidermis connected with the eccrine dermal duct, supporting the idea that certain palmoplantar epidermoid cysts may develop following the epidermoid metaplasia of eccrine ducts with HPV 60 infection.- - - - - - - - - - ranking = 3keywords = hybridization (Clic here for more details about this article) |
5/10. Primary squamous cell carcinoma of the stomach: a case report with immunohistochemical and molecular biologic studies.Primary squamous cell carcinoma (SCC) of the stomach is an extremely rare tumor and its pathogenesis is still unknown. We report a case of SCC of the stomach in a 69-year-old man. The patient's stomach contained an area of SCC surrounded by squamous metaplasia. To our knowledge, this is the first reported study to have investigated the pathogenesis of this tumor type by immunohistochemistry, liquid hybridization assay for human papilloma virus (HPV) infection, and polymerase chain reaction for Epstein-Barr virus (EBV) infection. These tests yielded proof of EBV infection in surgical specimens of the tumor. Therefore, we suggest that EBV infection may be involved in the pathogenesis of SCC arising in the stomach.- - - - - - - - - - ranking = 0.5keywords = hybridization (Clic here for more details about this article) |
6/10. Pseudoinfiltrative tubal metaplasia of the endocervix: a potential form of in utero diethylstilbestrol exposure-related adenosis simulating minimal deviation adenocarcinoma.We report three cases of unusual tubal-type endocervical glandular proliferations simulating minimal deviation adenocarcinoma in women with a history of in utero diethylstilbestrol (DES) exposure. The lesions were characterized by haphazard glandular proliferations extending from 3.4 to 6.1 mm into the endocervical stroma and to the margins of excision in all cases. Most of the glands were small to medium-sized and round; some exhibited a moderate degree of cystic dilatation, and occasional glands had curvilinear profiles. The glandular epithelium displayed extensive tubal-type differentiation in all cases. In two cases, the glands lacked cytologic atypia and mitotic activity, and in one case, there was mild to moderate nuclear atypia with occasional mitotic activity. Immunohistochemical studies showed diffuse expression of estrogen and progesterone receptors and essentially no expression of p16 in two cases tested; there was no expression of CD10 in one case that was tested. The Ki-67 proliferation index was zero in one case and 25% in another. Human papillomavirus dna was not detected by in situ hybridization in one case that was tested. The proliferations lacked features of mucinous and tubo-endometrioid types of minimal deviation adenocarcinoma. The clinicopathologic findings suggest the lesions are benign, and the association with in utero DES exposure raises the possibility that these could be a form of DES-related adenosis.- - - - - - - - - - ranking = 0.5keywords = hybridization (Clic here for more details about this article) |
7/10. Molecular evidence for progression of nephrogenic metaplasia of the urinary bladder to clear cell adenocarcinoma.Nephrogenic metaplasia or nephrogenic adenoma of the urinary tract may present a diagnostic challenge in surgical pathology practice. Previous case reports suggest the possibility of nephrogenic metaplasia progressing to clear cell adenocarcinoma, but a malignant potential of nephrogenic metaplasia is generally not acknowledged. A case of a 70-year-old female patient with multiple recurrences of nephrogenic metaplasia of the urinary bladder and subsequent development of clear cell adenocarcinoma is described. Immunohistochemical studies help to differentiate the 2 entities. Results of molecular studies, particularly comparative genomic hybridization analysis, suggest clonal evolution of nephrogenic metaplasia to clear cell adenocarcinoma in this case.- - - - - - - - - - ranking = 0.5keywords = hybridization (Clic here for more details about this article) |
8/10. Human papillomavirus type 31 dna detected in part of the dysplasia but in no part of the squamous metaplasia in a specimen taken from one patient.Using in situ hybridization, human papillomavirus (HPV 6, 16, 18, 31, 33) DNAs were detected in a cervical severe dysplasia accompanied by squamous metaplasia. It was found that, only HPV 31 dna was harbored in the cervical severe dysplasia, but HPV DNAs were not identified in a lesion of squamous metaplasia. The in situ hybridization method will be of use, therefore, when dysplasia with squamous metaplasia or other lesions are examined for HPV dna. In a cervical smear, HPV 31 dna could be detected on the nuclei of dysplastic cells, so this method is applicable to cervical smears. If squamous metaplasia is to be considered as a precursor lesion to cervical dysplasia, the HPV dna harbored in the dysplasia must also be detected in the accompanying squamous metaplasia. Our results suggested that not all squamous metaplasias were involved with HPV, as far as we were able to detect using five types of HPV dna probe.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
9/10. Extraosseous primary and recurrent giant cell tumors: transforming growth factor-beta1 and -beta2 expression may explain metaplastic bone formation.Giant cell tumor (GCT) of bone is a locally aggressive neoplasm with a high incidence of recurrence, usually at the site of previous osseous involvement. Primary and recurrent intraosseous lesions typically are lytic and do not show evidence of tumor-associated osteogenesis. Rarely, GCT recurs or is primary within soft tissue, and not infrequently, these extraosseous lesions show metaplastic bone formation that is visible radiographically. The authors report two recurrent and one primary case of extraosseous GCT, all of which exhibited significant deposits of metaplastic bone localized to the periphery of the lesions. in situ hybridization showed messenger rna (mRNA) for transforming growth factor beta1 (TGF-beta1) and transforming growth factor beta2 (TGF-beta2) in neoplastic stromal cells and osteoclast-like giant cells within the recurrent and primary extraosseous tumors as well as in active osteoblasts on the surfaces of recently formed spicules of metaplastic bone. in situ hybridization also revealed mRNA for TGF-beta1 and TGF-beta2 in primary intraosseous tumors from these cases and from four cases in which neither extraosseous recurrence nor osseous metaplasia was identified. In the microenvironment of the extraosseous soft tissue, production of these osteoinductive growth factors by GCT may have a paracrine effect on mesenchymal progenitor cells, thereby stimulating the osteoblastic differentiation and metaplastic bone formation associated with these lesions.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
10/10. Squamous metaplasia of the endometrium associated with HPV 6 and 11.Although uncommon in the endometrium, squamous metaplasia, dysplasia, and squamous carcinoma have been observed. Associated human papillomavirus (HPV) infection is also unusual, due at least in part to the fact that HPV requires specific characteristics of the target epithelium for infectivity. We report a case of extensive squamous metaplasia with focal low-grade squamous intraepithelial neoplasia of the endometrium coexistent with low-grade cervical intraepithelial neoplasia and an invasive squamous carcinoma of the vagina. in situ hybridization studies revealed HPV types 6 and 11 in both the cervical and endometrial lesions. This is the first report to date to demonstrate squamous epithelial metaplasia and dysplasia of the endometrium, associated with HPV dna of viruses typically of low oncogenic potential.- - - - - - - - - - ranking = 0.5keywords = hybridization (Clic here for more details about this article) |
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