E-cadherin/catenin complex status in solid pseudopapillary tumor of the pancreas.

Solid pseudopapillary tumor (SPT) of the pancreas is an uncommon neoplasm of uncertain lineage. They have been shown to express nuclear beta-catenin believed to be due to mutations of the beta-catenin gene. The aim of this study was to investigate the status of the E-cadherin/catenin complex in SPTs. We studied the expression of 4 principal members of the E-cadherin/catenin complex using immunohistochemistry and the E-cadherin gene status by screening all exons of the gene for mutations, in 6 cases of SPT. In addition to the nuclear localization of beta-catenin, we found nuclear localization of E-cadherin in all tumors with complete absence of membranous and cytoplasmic localization. Nuclear localization of E-cadherin was independent of beta-catenin. No mutations were identified in the E-cadherin gene in any of the tumors. Ten cases of pancreatic adenocarcinomas and 15 neuroendocrine tumors were studied as well for comparison. The reported changes in the expression of the principal members of the E-cadherin/catenin complex were unique to SPTs. Our study shows abnormalities in the expression of 4 principal members of the E-cadherin/catenin complex in SPTs, which may help to explain the discohesive nature of the cells and the cystic changes in these tumors, and provide additional diagnostic features.

Diagnosing pancreatic cancer: the role of percutaneous biopsy and CT.

AIMS: To determine the sensitivity and complications of percutaneous biopsy of pancreatic masses, and whether typical computed tomography (CT) features of adenocarcinoma can reliably predict this diagnosis. MATERIALS AND METHODS: A 5 year retrospective analysis of percutaneous core biopsies of pancreatic masses and their CT features was undertaken. Data were retrieved from surgical/pathology databases; medical records and CT reports and images. RESULTS: Three hundred and three patients underwent 372 biopsies; 56 of 87 patients had repeat biopsies. Malignancy was diagnosed in 276 patients, with ductal adenocarcinoma in 259 (85%). Final sensitivity of percutaneous biopsy for diagnosing pancreatic neoplasms was 90%; for repeat biopsy it was 87%. Complications occurred in 17 (4.6%) patients, in three of whom the complications were major (1%): one abscess, one duodenal perforation, one large retroperitoneal bleed. CT features typical of ductal adenocarcinoma were: hypovascular pancreatic mass with bile and/or pancreatic duct dilatation. Atypical CT features were: isodense or hypervascular mass, calcification, non-dilated ducts, cystic change, and extensive lymphadenopathy. Defining typical CT features of adenocarcinoma as true-positives, CT had a sensitivity of 68%, specificity of 95%, positive predictive value (PPV) of 98%, and negative predictive value of 41% for diagnosing pancreatic adenocarcinoma. CONCLUSION: Final sensitivity of percutaneous biopsy for establishing the diagnosis was 90%. CT features typical of pancreatic adenocarcinoma had high specificity and PPV. On some occasions, especially in frail patients with co-morbidity, it might be reasonable to assume a diagnosis of pancreatic cancer if CT features are typical, and biopsy only if CT shows atypical features.

Pylorus-preserving pancreaticoduodenectomy for advanced duodenal disease in familial adenomatous polyposis.

BACKGROUND: Although only 5 per cent of patients with familial adenomatous polyposis (FAP) die from duodenal cancer, a recent study indicated that the mortality rate is much higher in patients with Spigelman stage IV disease. This has prompted an increased rate of referral for excisional surgery and an analysis of the results. METHODS: Between January 1994 and June 2002, 16 patients with FAP (mean age 55 years; eight men) were referred to a single surgeon for pylorus-preserving pancreaticoduodenal resection for Spigelman stage IV duodenal adenomatosis. RESULTS: One patient died from multiple organ failure after relaparotomy for haemorrhage and a jejunal perforation; other major complications included anastomotic leak (one), primary haemorrhage (one), lymphatic leak (one), chylous ascites (one), pulmonary embolus (two) and prolonged delayed gastric emptying that required total parenteral nutrition (three). Overall there were 11 major complications in eight patients. Two patients developed insulin-dependent diabetes and one postprandial dumping. Postoperative histological examination revealed five unsuspected cancers, which led to four deaths within 3 years of surgery. One patient died 2 months after surgery from pulmonary thromboembolism and another at 5 months from an inoperable brain tumour. Nine of the 16 patients were alive and well at a mean of 38 months after surgery. CONCLUSION: The choice between continued endoscopic surveillance and excisional surgery for Spigelman stage IV duodenal disease remains finely balanced.

The effects of different viewing conditions on performance in simulated minimal access surgery.

This study aimed to assess performance in simulated minimal access surgery (MAS) tasks under a range of viewing conditions. MAS conventionally uses 2d viewing systems which produce a flat image. However, 3d viewing systems which produce stereoscopic depth information should in principle lead to better depth perception, and improve performance on tasks which require appropriate spatial representation of layout and depth. The study compared a novel 3d viewing system with a state of the art 2d viewing system and a direct viewing condition ('open surgery') as a point of reference. Tasks included pulling and cutting of threads using standard surgical instruments. Medical students (n = 16) were allocated to viewing conditions according to a Latin square and carried out 120 tasks each. Assessment was by means of a 3d movement tracking device providing a number of performance parameters (time on task, velocity, number of movements, distance travelled). In addition instrument movement was video-recorded and analysed by four observers to validate the tracking device. Results from tracking data and observer data were highly correlated (r > 0.85). While open surgery naturally scored highest, the key finding was the clearly superior performance in the 3d condition compared to 2d. Thus modern 3d viewing systems can improve performance in a realistic task.