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Query: UMLS:C0001418 (adenocarcinoma)
 68,496 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The pathobiology of precursor lesions leading to invasive pancreatic adenocarcinoma remains a controversial area, but knowledge of the mechanisms of tumorigenesis may lead to possibly earlier detection, prevention, and treatment in the future. We hypothesize that ductal hyperplasia and dysplasia of the pancreas represent precursor lesions and are part of a continuous developmental spectrum evolving into ductal adenocarcinoma of the pancreas. To further define this sequence, we studied the immunohistochemical markers HER-2/neu, K-ras, and p53 in 15 adenocarcinomas and 15 nonmalignant specimens of the pancreas. The 15 nonmalignant specimens of the pancreas included both normal pancreas and chronic pancreatitis. Overall, HER-2/neu was positive in normal ducts, ductal hyperplasia, dysplasia, and carcinoma cells in 0 of 30, 11 of 20 (55%), 10 of 15 (67%), and 12 of 15 (80%), respectively, with progressive increase in the intensity of staining; p53 was positive in 1 of 30 (3%), 0 of 20, 3 of 15 (20%), and 13 of 15 (80%), respectively, and K-ras was positive in 1 of 30 (3%), 6 of 20 (30%), 11 of 15 (73%), and 8 of 15% (53%), respectively. These data support the hypothesis that ductal hyperplasia and dysplasia of the pancreas represent precursor lesions, and, in a fashion similar to that in colorectal tumorigenesis, pancreatic cancer seems to accumulate progressive genetic alterations.
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PMID:Immunohistochemical evaluation of K-ras, p53, and HER-2/neu expression in hyperplastic, dysplastic, and carcinomatous lesions of the pancreas: evidence for multistep carcinogenesis. 1002 38

The role of MR imaging in the assessment of pancreatic adenocarcinoma is in identification, characterization and staging of the neoplastic lesion. Technique optimization is required in order to obtain high qualities images competitive with spiral CT. The choice of imaging protocol is strictly related to the available equipment as well as fast imaging capabilities. Contrast-enhanced study using breath-hold sequences is required if working at high field strength with high gradient performance; on mid-low field strength nonbreath-hold acquisition techniques, using respiratory compensation techniques, can be implemented. The use of fat saturation pulses may increase the sensitivity of MR in detecting pancreatic lesions. Other advantages of MR imaging are represented by the availability of additional noninvasive techniques for the evaluation of the biliary tree (MR-cholangiopancreatography) and splanchnic vessels (MR-angiography). Lesion identification is based on TIw sequences where the lesion appears hypointense compared with the surrounding pancreas; increased lesion-pancreas contrast is obtained when fat suppression is used. On dynamic studies following gadolinium injection, pancreatic tumors are hypovascular compared with surrounding normal pancreatic gland. Problems in correctly defining the size of the lesions may be encountered in patients presenting with inflammatory changes of the pancreatic parenchyma surrounding the carcinoma (epineoplastic pancreatitis). For lesion characterization MRI is not able to characterize focal pancreatic lesions, allowing a differential diagnosis between pancreatic cancer and focal hypertrophic chronic pancreatitis. Even the use of MR-cholangiopancreatography is not helpful for characterizing focal pancreatic masses. MR imaging is accurate in local staging (assessment of peripancreatic fat infiltration) thanks to the higher contrast resolution, but in vascular staging and in the evaluation of lymphnodal involvement it suffers the same limitations as computed tomography. Future perspective are represented by the use of magnetic resonance angiography for the evaluation of vascular encasement and the use of specific contrast agents for lymphadenopathy. Identification of hepatic metastases with MRI has been proven to be high, with sensitivity and specificity comparable to CT. The use of liver-specific contrast agents (either positive or negative) is becoming almost routine and it is proving to further improve the diagnostic value of MRI.
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PMID:[MR imaging of pancreatic neoplasms]. 1023 72

Intraductal papillary-mucinous neoplasms (IPMNs) of the pancreas are rare lesions. We undertook this study to analyze these tumors by focusing on the diagnostic criteria and correlating the histologic features with clinical prognosis. Twenty-two cases of IPMN were retrieved from the Endocrine Tumor Registry of the Armed Forces Institute of Pathology. Blocks or unstained slides were available for histochemical and immunohistochemical studies (including proliferative markers and cell cycle regulators) and K-ras oncogene mutations in 15 cases. Patient follow-up was obtained in all of the cases. IPMN occurs in both genders with a slight male predominance, with a mean age at presentation of 64.4 years (range, 48-85 yr). The patients presented with abdominal pain. The neoplasms were radiologically and grossly cystic, usually (18 cases of 22) located in the head of the pancreas. Histologically, the tumors consisted of intraductal papillary proliferations protruding into and expanding the pancreatic ducts. Invasion into the surrounding pancreatic parenchyma was detected in 15 cases. Chronic pancreatitis was present in all of the cases. p27 immunoreactivity always exceeded the immunoreactivity of cyclin E. K-ras oncogene mutations were detected in two cases. Patients were treated with a complete surgical resection (n = 7) or a Whipple procedure (n = 13). Only 2 of 22 patients died of disease (3 died immediately postoperatively and 3 died of unrelated causes), whereas the remaining 14 patients were alive at last follow-up, without evidence of disease, an average of 58.2 months after initial presentation. IPMNs are rare, distinctive neoplasms, with complex intraductal papillae, that can be easily separated from in situ ductal adenocarcinoma and mucinous cystic neoplasms. The high ratio of p27 protein to cyclin E supports the excellent prognosis of these neoplasms, despite the presence of invasion and K-ras oncogene mutation.
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PMID:A clinicopathologic and immunohistochemical study of 22 intraductal papillary mucinous neoplasms of the pancreas, with a review of the literature. 1034 91

This article reviews age-related alterations in pancreatic structure and function and provides an update of advances in clinical understanding of the epidemiology, pathogenesis, and pathophysiology of acute pancreatitis, chronic pancreatitis, and pancreatic adenocarcinoma. This article also provides guidelines for the integration of recent radiologic, endoscopic, surgical, and oncologic advances in these areas into the current clinical practice of the gerontologist and gastroenterologist.
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PMID:Pancreatic disease in the elderly. 1039 43

Matrix metalloproteinases (MMPs) have been implicated in the invasion and metastasis of tumor cells. To elucidate the involvement of MMP-1 in human pancreatic ductal adenocarcinoma, we performed immunohistochemical analysis on tissues from 2 fetal pancreases, 5 normal pancreases, 6 cases of chronic pancreatitis, and 46 pancreatic ductal adenocarcinomas. In addition, among the pancreatic carcinomas, we compared MMP-1 expression in relation to the degree of differentiation, lymph node metastasis, and depth of invasion of the carcinoma. MMP-1 was expressed faintly in fetal and normal pancreatic tissues. Among the 46 pancreatic carcinomas, 33 (72%) showed positive staining for the MMP-1 protein. There was no difference in the degree of differentiation. In situ hybridization confirmed the presence of MMP-1 mRNA in the pancreatic carcinomas. Expression of MMP-1 mRNA was also detected in two human pancreatic carcinoma cell lines and three pancreatic carcinoma tissues by the reverse transcription polymerase chain reaction method. MMP-1 was expressed in the carcinoma cells themselves and in stromal fibroblasts. Patients with MMP-1 positivity in the primary site had a significantly poorer prognosis than patients who were MMP-1 negative (P < .05). MMP-1 expression, however, had no relation to the presence of lymph node metastasis, tumor size, or tumor-node-metastasis stage in pancreatic carcinomas. These findings suggest that MMP-1 expression is related to the carcinogenesis and prognosis of human pancreatic ductal adenocarcinoma.
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PMID:Expression of the MMP-1 in human pancreatic carcinoma: relationship with prognostic factor. 1043 Feb 70

Chronic pancreatitis (CP) is generally considered as a risk factor for pancreatic adenocarcinoma (PAC). However, the cumulative risk differs among the epidemiological studies. In the individual patient, the differential diagnosis between PAC and CP cannot be always resolved preoperatively and even intraoperatively. In those cases, the uncertainty can only be answered with histological studies of the resected specimen after a radical resection, provided that this type of surgery can be performed with a reasonable risk in a surgically fit patient. The type of resection depends on the location of the suspicious mass. For masses in the tail of the pancreas, a distal pancreatectomy is the procedure of choice. For suspicious lesions in the head of the pancreas, a pancreatoduodenectomy (PD) should be performed. The surgeon and the patient should also acknowledge that a radical resection will occasionally be performed for a suspected malignancy only to find that another etiology (i.e. CP) accounts for the suspicious pancreatic mass. In the presence of a strong suspicion for an underlying malignancy in a patient with head dominant CP, PD should probably be preferred over the newer organ-preserving Beger and Frey procedures, since it is an adequate procedure for both CP and PAC.
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PMID:Pancreatic cancer in patients with chronic pancreatitis: a challenge from a surgical perspective. 1044 29

The majority of pancreatic carcinomas contain a mutation at codon 12 of the K-ras oncogene. We have analysed 87 samples from 76 patients who underwent surgery because of different pancreatic diseases to evaluate whether the detection of K-ras mutations may be helpful to discriminate between chronic inflammation and neoplastic growth. Mutation analysis was performed using a semi-nested PCR followed by a selective restriction enzyme digestion. The correlation of clinical follow ups with the results of the molecular analysis was performed from 47 patients. K-ras mutations were detected in 50% of adenocarcinomas and no point mutation was found in normal pancreatic tissue and in tumor tissue from entities other than pancreas. Otherwise, K-ras mutations were detected in tissue samples from two patients with chronic pancreatitis, and one patient was found to have an adenocarcinoma after additional clinical investigation. Further studies especially follow ups will be helpful to get a better insight into the pathogenesis of pancreatic tumors and may be useful as an early diagnostic test.
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PMID:Analysis of K-ras mutations in pancreatic tissue after fine needle aspirates. 1047 Jan 78

Hereditary pancreatitis is a rare condition characterized by acute and chronic pancreatitis transmitted in an autosomal dominant fashion. There also is an epidemiologic link to pancreatic cancer in some affected families. Failure of a secondary brake mechanism responsible for inactivation of prematurely activated cationic trypsin in acinar cells seems to be the fundamental defect in type I hereditary pancreatitis (R117H cationic trypsin), and also may explain the pathogenesis of type II hereditary pancreatitis (N211 cationic trypsin). The diagnosis is made based on clinical history and, in certain cases, by molecular diagnostic testing for these gene defects. Medical management of acute and chronic hereditary pancreatitis currently does not differ from that of nonhereditary AP. As in nonhereditary pancreatitis, the surgical approach must be tailored to the individual problem, with an understanding that disease restricted to the head of the gland is atypical and that residual acinar tissue continues to drive the disease state. Although diagnosis and management of pancreatic adenocarcinoma are similar in this cohort, the increased age-accumulated risk suggests that thoughtful screening protocols eventually may be clinically and cost-effective.
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PMID:Hereditary pancreatitis. Gene defects and their implications. 1047 Mar 21

Neoplastic transformation of epithelial cell sis commonly associated with altered synthesis of mucin glycoproteins. Few studies have been performed on the correlation between MUC 1 expression and pancreatic carcinoma using immunohistochemical methods. We compared the patterns of MUC 1 expression in normal pancreatic tissue, in pancreatic carcinoma, and in chronic pancreatitis. Immunohistochemical studies were performed using 3 monoclonal anti-MUC 1 antibodies (12C10, 1G5, and H23) on surgical specimens and on fine-needle aspiration biopsy specimens. In the neoplastic cells from adenocarcinomas, high levels of cytoplasmic MUC 1 expression were observed, with some membrane staining. No such cytoplasmic expression was observed in normal tissue, tissue from chronic pancreatitis, or benign neoplastic tissue. These data show conspicuous quantitative and qualitative differences between the patterns of MUC 1 expression observed in nonmalignant vs malignant pancreatic tissue and may be useful in the histologic diagnosis of adenocarcinoma in biopsy samples.
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PMID:Differential MUC 1 expression in normal and neoplastic human pancreatic tissue. An immunohistochemical study of 60 samples. 1054 50

AIMS: Long-term survival after surgery for pancreatic cancer remains very low and it is particularly important that minimal surgery-related morbidity and mortality rates are achieved. It has been stated that centres performing small numbers of proximal pancreaticoduodenectomies are likely to have high morbidity and mortality rates. The results of pancreatic surgery in a district general hospital are reported. METHODS: This was a retrospective analysis of all pancreaticoduodenectomies over 4 years. RESULTS: Twenty-one selected patients underwent proximal pancreaticoduodenectomy and two patients total pancreatectomy over a 4-year period from 1995 to 1999. The operations were performed by two surgeons with a special interest in upper gastrointestinal surgery. The median age was 62 (38-83) years. There were 14 men and nine women. Fifteen patients had adenocarcinoma of the head of the pancreas, five had ampullary carcinoma, one duodenal carcinoma and there was one case of chronic pancreatitis. Six patients had pylorus-preserving pancreaticoduodenectomy (PPPD) and 15 had a standard Whipple procedure. The median stay in hospital was 20 (13-26) days. Two patients had a pancreatic leak, one of whom developed an intra-abdominal abscess which was treated successfully by percutaneous drainage. Six patients experienced delayed gastric emptying, two of whom had PPPD. Both the 30-day and in-hospital mortality rates were zero. The median number of lymph nodes dissected was 12 and in 11 patients no nodal metastasis was found. CONCLUSIONS: It is possible to perform pancreatic surgery in a district general hospital and achieve results that are comparable to those of specialist centres.
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PMID:Experience of pancreaticoduodenectomy in a district general hospital 1071 49


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