1/19. Detection of mutations of p53 tumor suppressor gene in pancreatic juice and its application to diagnosis of patients with pancreatic cancer: comparison with K-ras mutation.Because of the difficulty in obtaining biopsy specimens from pancreatic cancer patients, K-ras mutation analysis in pancreatic juice has been used for specific diagnosis. But recently, false positives have been obtained with this method. To improve the genetic diagnosis of pancreatic cancer, detection of p53 gene mutation in pancreatic juice was studied. pancreatic juice was sampled endoscopically. Single-strand conformation polymorphism analysis was used for p53 mutation analysis. Furthermore, K-ras mutations at codon 12 were also studied in the same pancreatic cancer patients. Of 26 cases of pancreatic cancer, p53 mutations were detected in 11 (42.3%). No mutations were seen in the cases with mucin-producing adenoma nor with chronic pancreatitis. K-ras mutations were detected in 84.0% of cases by RFLP analysis, which has high sensitivity, and in 65.3% by hybridization protection assay, which has high specificity. Using a combination assay with both genes, genetic abnormalities were detected in 92.0% by RFLP and 73.1% by hybridization protection assay including two cases in which p53 alone was positive by both methods. The specificity of p53 mutation for pancreatic cancer is very high. Therefore, simultaneous analysis of p53 and K-ras mutation is suggested to enhance the genetic diagnosis of pancreatic cancer.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
2/19. Lymphoepithelial cyst of the pancreas. No evidence for Epstein-Barr virus-related pathogenesis.Compared to pseudocyst formation after prior pancreatitis, true cysts of the pancreas are rare. Pancreatic cysts with irregular wall components or a mucinous content raise the suspicion for the presence of a cystic neoplasm, and surgical resection is recommended. A case of a patient with a history of prostate cancer is described in whom a cyst of the pancreatic tail was discovered incidentally. Based on the radiographic features, which did not support the presence of a serous cystadenoma, a spleen-preserving distal pancreatectomy was performed. Histologic features were characteristic for a lymphoepithelial cyst (LEC) of the pancreas, lined with thinned squamous epithelium surrounded by benign lymphoid tissue. Since LECs of the parotid gland, which are associated with acquired human immunodeficiency, are frequently related to Epstein-Barr virus (EBV) infection, EBV in situ hybridization was performed and did not reveal evidence for EBV. Twenty-eight instances of pancreatic LECs have been reported, primarily affecting adult males, without evidence of increased numbers of EBV-positive cells. The pathogenesis, differential diagnosis, and clinical implications of lymphoepithelial pancreatic cysts are discussed.- - - - - - - - - - ranking = 0.5keywords = hybridization (Clic here for more details about this article) |
3/19. Pleomorphic carcinoma of the pancreas with massive lymphocytic stromal infiltration and long-term survival after resection.BACKGROUND: Pleomorphic carcinoma of the pancreas is a rare tumor with an extremely poor prognosis. The mean survival time is reported to be approx 3 mo. CLINICAL AND HISTOLOGICAL FINDINGS: A 56-yr-old Japanese man presenting with general fatigue, loss of weight, and high fever was found to have a large hypervascular mass in the body of the pancreas with regional lymph node metastases. Laboratory investigation revealed leukocytosis, elevated erythrocyte sedimentation rate (ESR), and high serum c-reactive protein (CRP). In addition to distal pancreatectomy, splenectomy and lymph node dissection were performed. histology showed the presence of pleomorphic large cells with bizarre mono- or multinuclei, growing in sarcomatoid pattern without mutual cohesiveness. Another noticeable finding was massive lymphocytic infiltration of the stroma of the neoplasm. Immunohistochemically, the infiltrating lymphocytes consisted of cytotoxic type of T cells. In addition, in situ hybridization for Epstein-Barr virus-encoded rna (EBAR-1) was not seen in the tumor cells or in lymphocytes. After surgery the patient did not undergo chemotherapy or radiotherapy. He has been well without recurrence for 8 yr. CONCLUSION: We report a case of pleomorphic carcinoma, possibly lymphoepithelioma-like carcinoma, of the pancreas with massive lymphocytic stromal infiltration and long-term survival after resection. Cytokine responses and cellular immunoreactivity may have contributed to a long-term survival, which is unusual in the common type of pleomorphic carcinoma of the pancreas.- - - - - - - - - - ranking = 0.5keywords = hybridization (Clic here for more details about this article) |
4/19. monosomy of chromosome 11 in pituitary adenoma in a patient with familial multiple endocrine neoplasia type 1.multiple endocrine neoplasia type 1 (MEN 1) represents an endocrine syndrome characterized by complex pituitary, parathyroid and pancreatic neoplasia. loss of heterozygosity of the specific region 11q13 has been reported in several tumours from patients with MEN 1 inherited disorder. We present a case of a young patient with familial MEN 1 syndrome with a pituitary adenoma exhibiting monosomy of chromosome 11. The patient presented with a large and rapidly growing pituitary adenoma associated with markedly elevated serum PRL levels, progressive bilateral visual loss and hydrocephalus. The resected adenoma was chromophobic, mainly PRL-producing and to a lesser degree immunoreactive for GH. fluorescence in situ hybridization (FISH) using an alpha-satellite centromeric probe detected loss of one chromosome 11 copy in almost all pituitary adenoma cells. Clinical and biochemical studies revealed parathyroid hyperplasia and MRI studies detected a pancreatic tumour in addition to the pituitary adenoma. To our knowledge this is the first study reporting monosomy 11 in pituitary adenoma in a patient associated with familial MEN 1 syndrome.- - - - - - - - - - ranking = 0.5keywords = hybridization (Clic here for more details about this article) |
5/19. No constant relationship between islet amyloid polypeptide (IAPP) and insulin expression in insulinomas.The relationship between insulin and islet amyloid polypeptide (IAPP) expression was studied at the level of rna and peptide in 3 patients operated on for insulinoma. Two patients had a solitary tumour; one patient suffered from the MEN-I syndrome. In the 3 tumours, as in normal pancreas, the same 2 IAPP-specific mRNA species, approximately 1600 and 2100 nucleotides, respectively, were detected. In 2 patients, the IAPP mRNA concentration of the tumour was lower than the insulin mRNA concentration; in the third patient, however, the specific IAPP hybridization signal was at least equal to that for insulin. Amyloid deposits were found in one solitary tumour and in the tumour from the MEN-I patient, both staining strongly positive with anti-IAPP antibodies; cytoplasmatic IAPP was weak. In conclusion, at least in some insulinomas, no constant relationship exists between insulin and IAPP expression.- - - - - - - - - - ranking = 0.5keywords = hybridization (Clic here for more details about this article) |
6/19. Epstein-Barr virus-associated lymphoepithelial carcinoma in the pancreas.Lymphoepithelial carcinoma is a relatively common malignancy in the nasopharyngeal region, but it rarely occurs at other sites. We report a lymphoepithelial carcinoma in the pancreas of a 65-year-old male patient operated on for a gastric stump carcinoma 7 years previously. The solitary tumor in the pancreas presented as a circumscribed lesion and measured 5.5 cm in diameter. The tumor was densely infiltrated by lymphocytes, and the neoplastic cells fulfilled all criteria for a lymphoepithelial carcinoma. Several peripancreatic lymph node metastases were observed. Marked reactivity for Epstein-Barr virus (EBV) early rna (EBER) was detected in the majority of tumor cells using in situ hybridization. Nuclear EBER signals were also detected in the previously operated gastric stump adenocarcinoma, which also exhibited focal lymphocytic infiltration but otherwise displayed a histology different from lymphoepithelial carcinoma and did not show local recurrence. Even though an unusually late metastasis of the gastric carcinoma cannot be ruled out, we favor the hypothesis that this patient developed an EBV-related pancreatic lymphoepithelial carcinoma as a second primary tumor, based on the considerable delay of this tumor manifestation, the unusual site, the pathologic presentation, the exclusively peripancreatic nodal spread, and the different histology of the lesion.- - - - - - - - - - ranking = 0.5keywords = hybridization (Clic here for more details about this article) |
7/19. Oligoclonal T-cell populations in an inflammatory pseudotumor of the pancreas possibly related to autoimmune pancreatitis: an immunohistochemical and molecular analysis.Inflammatory pseudotumors (IPT), also known as inflammatory myofibroblastic tumors (IMT), are benign inflammatory processes that may have an infectious etiology and are very rare in the pancreatico-biliary region. Recent studies suggest a biological distinction between IPT and IMT, the latter being a true neoplastic process. We describe a case of pancreatic IPT, originally diagnosed as malignancy, which presumably recurred 4 months after the operation. Histologically, the tumor consisted of a smooth muscle actin and CD68-positive spindle cell population and a more abundant mononuclear inflammatory cell population, primarily composed of macrophages and t-lymphocytes. Inflammatory cells were the source of connective tissue growth factor and transforming growth factor-beta1 and tended to accumulate around nerves and blood vessels, as well as around residual pancreatic parenchymal elements, where an intense angiogenetic response was detected. comparative genomic hybridization analysis of the tumor showed no chromosomal imbalances. polymerase chain reaction-based analysis of T-cell receptor gamma gene rearrangement revealed an oligoclonal pattern. These findings suggest that the pathogenesis of aggressive cases of IPT could be related to the development of an intense and self-maintaining immune response, with the emergence of clonal populations of t-lymphocytes. The relation of the pancreatic IPT to autoimmune pancreatitis is emphasized.- - - - - - - - - - ranking = 0.5keywords = hybridization (Clic here for more details about this article) |
8/19. Differential diagnosis of non-epithelial tumors of the pancreas: malignant non-epithelial pancreatic tumor with focal pigmentation.Non-epithelial tumors only rarely affect the pancreas. In this report, we describe a malignant non-epithelial tumor with combined characteristics of malignant peripheral nerve sheath tumor (MPNST) and malignant melanoma. To more closely define the differential diagnosis of MPNST with focal pigmentation versus metastatic melanoma resembling MPNST, the tumor was investigated using histomorphology, immunohistochemistry, electron microscopy, and comparative genomic hybridization. As a result, from these analyses and from clinical findings, the diagnosis of a pancreatic MPNST with focal pigmentation was favored. However, the diagnosis of a malignant melanoma or a composite tumor could not be definitely ruled out, due to the considerable morphological and genotypical overlap between both entities, which can be explained by the close histogenetic relationship between both tumor entities.- - - - - - - - - - ranking = 0.5keywords = hybridization (Clic here for more details about this article) |
9/19. Ectopic bioactive luteinizing hormone secretion by a pancreatic endocrine tumor, manifested as luteinized granulosa-thecal cell tumor of the ovaries.Endocrine pancreatic tumors are rare neoplasms consisting of multipotent cells capable of secreting various bioactive substances causing characteristic clinical syndromes. Ovarian stromal hyperthecosis is characterized by varying degrees of luteinized stromal cell proliferation after sustained LH and/or human chorionic gonadotropin stimulation, clinically manifested by symptoms/signs of virilization resembling the polycystic ovary syndrome (PCOS). We report a case of ectopic bioactive LH production from a pancreatic endocrine tumor in a 33-yr-old woman with rapidly developing symptoms/signs of hyperandrogenism and markedly elevated serum androgen and LH levels leading to hyperthecosis and bilateral luteinized granulosa-thecal cell tumors of the ovaries. Although the patient was initially thought to have either severe PCOS or an LH-secreting pituitary tumor, an LH-producing pancreatic endocrine tumor bearing somatostatin receptors was demonstrated on scintigraphy with [111In]octreotide and abdominal imaging. Symptoms and signs of hyperandrogenism resolved after the resection of the tumor. immunohistochemistry, in situ hybridization, and electron microscopy studies confirmed LH synthesis by the tumor cell. Although extremely rare, ectopic LH production from nonpituitary endocrine tumors should be considered in the differential diagnosis of hyperandrogenism, particularly when associated with highly elevated serum LH levels.- - - - - - - - - - ranking = 0.5keywords = hybridization (Clic here for more details about this article) |
10/19. Pediatric pancreatoblastoma: histopathologic and cytogenetic characterization of tumor and derived cell line.Little is known of the molecular events underlying the genesis of pancreatoblastoma tumors in the pediatric population. Such studies have been limited by the rare nature of the disease, infrequent reports detailing cytogenetic alterations, and the lack of availability of cell lines for biologic studies. We present the isolation of a cell line from a 14-year-old boy with malignant pancreatoblastoma, and its cytogenetic characterization using spectral karyotyping and comparative genomic hybridization (CGH). The cytogenetic analysis revealed an exceedingly complex cytogenetic karyotype, with 33 aberrant chromosomes. CGH revealed multiple regions of chromosomal loss and gain, including a region on 8q gained in adult pancreatic cancers, one that frequently contains the MYC oncogene.- - - - - - - - - - ranking = 0.5keywords = hybridization (Clic here for more details about this article) |
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