Stomach arteriovenous malformation resected by laparoscopy-assisted surgery: A case report.

Arteriovenous malformations of the stomach are an uncommon cause of upper GI bleeding. We report a case of stomach arteriovenous malformation in an 85-year-old Asian man who presented with massive hematemesis. Initial esophagogastroduodenoscopy did not detect this lesion, but contrast multi-detector CT confirmed GI bleeding. Multi-detector CT revealed a mass of blood vessels underlying the submucosa that arose from the right gastroepiploic artery. Repeat esophagogastroduodenoscopy showed that the lesion was a submucosal tumor with erosion and without active bleeding in the lower body of the stomach on the greater curvature. We performed partial gastrectomy via laparoscopy-assisted surgery. The histopathological diagnosis was arteriovenous malformation.

Keratinocyte growth factor induces matrix metalloproteinase-9 expression and correlates with venous invasion in pancreatic cancer.

Keratinocyte growth factor (KGF), also known as fibroblast growth factor-7, and KGF receptor (KGFR) play important roles in the growth of epithelial cells and are overexpressed in a variety of malignant epithelial tumors, including pancreatic ductal adenocarcinoma (PDAC). We previously reported that co-expression of KGF and KGFR in PDAC is associated with venous invasion, enhanced vascular endothelial growth factor A expression and poor prognosis. Matrix metalloproteinase-9 (MMP-9) is known to participate in the degradation of type IV collagen, which is a primary component of extracellular matrices in the vascular basement membrane. In the present study, we examined the expression and roles of KGF, KGFR and MMP-9 in human PDAC cell lines and tissues. Quantitative real-time polymerase chain reaction analysis demonstrated the expression of MMP-9 mRNA in all eight PDAC cell lines. KGF, KGFR and MMP-9 were, respectively, expressed in 27 (43%), 23 (37%) and 35 (56%) of 63 patients. Each expression of KGF, KGFR or MMP-9 correlated positively with venous invasion. Furthermore, expression of KGF or MMP-9 correlated positively with liver metastasis. KGF-positive cases exhibited shorter survival than KGF-negative cases, while KGFR and MMP-9 expression were unrelated to prognosis. Administration of recombinant human KGF increased MMP-9 expression in PDAC cells, while transient transfection with short hairpin RNAs targeting KGF transcripts reduced MMP-9 expression in PDAC cells. Moreover, recombinant human KGF significantly enhanced migration and invasion of PDAC cells. These findings suggest that KGF and KGFR promote venous invasion via MMP-9 in PDAC, and closely correlate with liver metastasis. The KGF/KGFR pathway may be a critical therapeutic target for PDAC metastasis.

Current surgical treatment for chronic pancreatitis.

Chronic pancreatitis (CP) is a painful, yet benign inflammatory process of the pancreas. Surgical management should be individualized because the pain is multifactorial and its mechanisms vary from patient to patient. Two main pathogenetic theories for the mechanisms of pain in CP have been proposed: the neurogenic theory and the theory of increased intraductal/intraparenchymal pressures. The latter theory is strongly supported by the good results of drainage procedures in the surgical management of CP. Other possible contributing factors include pancreatic ischemia; a centrally sensitized pain state; and the development of complications, such as pseudocysts and stenosis of the duodenum or common bile duct. Common indications for surgery include intractable pain, suspicion of neoplasm, and complications that cannot be resolved with radiological or endoscopic treatments. Operative procedures have been historically classified into 4 categories: decompression procedures for diseased and obstructed pancreatic ducts; resection procedures for the proximal, distal, or total pancreas; denervation procedures of the pancreas; and hybrid procedures. Pancreaticoduodenectomy and pylorus-preserving pancreaticoduodenectomy, once the standard operations for patients with CP, have been replaced by hybrid procedures, such as duodenum-preserving pancreatic head resection, the Frey procedure, and their variants. These procedures are safe and effective in providing long-term pain relief and in treating CP-related complications. Hybrid procedures should be the operations of choice for patients with CP.

Laparoscopic distal pancreatectomy preserving spleen and splenic vessels for pancreatic insulinoma.

We describe a 43-year-old woman who underwent laparoscopic distal pancreatectomy preserving the spleen and splenic vessels for the treatment of insulinoma in the pancreatic body. The patient experienced cold sweats on fasting, received diagnosis of insulinoma, and was referred to our hospital for laparoscopic surgery. Blood biochemistry studies showed low fasting blood glucose of 42 mg/dL, serial immunoreactive insulin of 15.2 microU/mL, and a Fajans index (immunoreactive insulin/blood glucose) of 0.36 (normal <0.30). Contrast-enhanced early-phase computed tomography of the abdomen showed a circular, intensely stained, 1.6-cm-diameter tumor in the pancreatic body close to the main pancreatic duct. A solitary insulinoma of the pancreatic body was diagnosed on the basis of the result of hematologic studies, and diagnostic imaging results. Because of the location of the tumor, we elected to perform distal pancreatectomy preserving the spleen and splenic vessels, rather than enucleation. Insulin and blood glucose levels were monitored during surgery. Before removal of the tumor, insulin levels remained consistently high, never decreasing to less than 10 microU/mL. After surgery, insulin levels decreased rapidly, to less than 5 microU/mL within 30 minutes and subsequently remained at the new low level, leading us to conclude that the entire tumor had been removed. There were no postoperative complications, and the patient was discharged from the hospital on day 7. There was no major intraoperative bleeding other than at the resected surface. The patient was ambulatory soon after the procedure, and had a brief hospital stay therefore, the surgery was judged to have been highly useful in this case.

Overexpression of PIK3CA is associated with lymph node metastasis in esophageal squamous cell carcinoma.

The genomic region containing PIK3CA was found to be amplified in esophageal squamous cell carcinoma (ESCC) tissue. PIK3CA at 3q26, which encodes the p110alpha catalytic subunit of phosphatidylinositol (PI) 3-kinase, is a unique intracellular signal transducer characterized by its lipid substrate specificity. In order to characterize PIK3CA in ESCC, we investigated hot-spot mutations in exons 1, 9 and 20, the copy number gain, the expression levels of mRNA and protein. Analysis in exon 9 of the PIK3CA gene revealed mutation in 7.7% (4 of 52) of ESCC samples. No mutation was detected in either exon 1 or exon 20. Copy number amplifications of PIK3CA were found in 12 of the 45 patients (26.7%). PIK3CA mRNAs were examined in 37 ESCC patients as determined by quantitative RT-PCR and the mean mRNA level of PIK3CA in ESCC tissues was 2.61-fold higher compared with that in corresponding non-tumorous esophageal epithelia (P<0.001). Immunohistochemically, positive immunoreaction for PIK3CA was detectable in 33 of 66 (50.0%) ESCC cases, while it was not detectable in the remaining 33 cases. Furthermore, comparing the cases with negative staining with those with positive staining for PIK3CA, the presence of node metastasis was significantly correlated with those with positive staining (P<0.05). This study is the first report providing comprehensive analysis of PIK3CA expression in ESCC. These results indicate that PIK3CA may play a crucial role in the development of ESCC and serve as an indicator for lymph node metastasis.

Nestin expression correlates with nerve and retroperitoneal tissue invasion in pancreatic cancer.

Nestin was first described as an intermediate filament protein expressed in neuroepithelial stem cells. Nestin expression has also been reported in brain tumors, schwannomas, gastrointestinal stromal tumors, and melanomas. In the pancreas, Nestin expression has been detected in exocrine and mesenchymal cells, including stellate cells, pericytes, and endothelial cells. In the present study, we examined Nestin expression in human pancreatic ductal adenocarcinoma and sought to determine its role in this malignancy. Reverse transcription-polymerase chain reaction analysis demonstrated the presence of Nestin mRNA in all 10 tested pancreatic cancer cell lines, and quantitative reverse transcription-polymerase chain reaction revealed that Nestin mRNA levels were highest in PANC-1 cells and lowest in PK-8 cells. Immunofluorescent analysis revealed that Nestin localized in the outer cytoplasm of PANC-1 cells. Nestin immunoreactivity was present in the cancer cells in 20 (33.3%) of 60 cancer cases, and its expression was confirmed by in situ hybridization. Nestin expression was also increased in peripheral nerve fibers adjacent to cancer cells and in peripheral nerve fibers invaded by cancer cells. Clinicopathologically, there was a statistically significant association between Nestin expression in pancreatic cancer cells and nerve invasion (P = .010) and the presence of cancer cells in the tumor resection margins (P = .003). Nestin-positive cases exhibited similar survival after resection by comparison with Nestin-negative cases, irrespective of whether they were given adjuvant therapy. These findings indicate that Nestin expression in pancreatic cancer cells may contribute to nerve and stromal invasion in this malignancy.

SnoN overexpression is predictive of poor survival in patients with esophageal squamous cell carcinoma.

BACKGROUND: Earlier studies have identified the minimal overlapping region of amplification at 3q26 in esophageal squamous cell carcinoma (ESCC) by comparative genomic hybridization (CGH) analysis. These include PIK3CA which encodes the p110alpha catalytic subunit of phosphatidylinositol (PI) 3-kinase, a telomerase RNA component (TERC), a squamous cell carcinoma-related oncogene (SCCRO), ecotropic viral integration site-1 (EVI-1), and a Ski-related novel oncogene (SnoN). In the present study, we investigated the mRNA levels of four candidate genes (TERC, SCCRO, EVI-1, and SnoN) to determine whether genes other than PIK3CA are targets for amplification at 3q26 in ESCC. And also, we examined SnoN expression in ESCC samples. METHODS: Fifty-nine representative cases with ESCC were selected from our archives. We performed quantitative RT-PCR of four candidate genes (TERC, SCCRO, EVI-1, and SnoN) and immunohistochemistry for SnoN. Finally, we correlated these findings with the clinicopathological characteristics to determine their interrelationship. RESULTS: Among the four genes we tested, only SnoN mRNA was consistently overexpressed in primary ESCC, compared with those in corresponding nontumorous esophageal epithelia (P < 0.001). Immunoreactive SnoN was detectable in 31 of 59 (52.5%) esophageal squamous cell carcinoma specimens. The levels of SnoN expression were found to correlate with the depth of invasion and recurrence (P < 0.05). Furthermore, patients with positive staining for SnoN displayed more unfavorable outcomes than patients with negative staining (P < 0.05). CONCLUSION: SnoN is likely to be the target of the amplification at 3q26 in ESCC and plays an important role in the development of ESCC, influencing disease-specific survival.

Adenoma of the minor papilla associated with pancreas divisum.

Tumors of the minor papilla of the duodenum are quite rare. We report the first documented case of an adenoma of the minor papilla complicating pancreas divisum. A 52-year-old woman was admitted to our hospital for treatment of an asymptomatic duodenal tumor detected by computed tomography scan. Endoscopy showed an 18-mm, whitish-colored, sessile mass located in the descending duodenum proximal to a normal appearing major papilla. Endoscopic retrograde pancreatography revealed divisum of the pancreas with dilatation of pancreatic duct ranged in the dorsal pancreas. Transduodenal minor papillectomy was performed because there is malignant potential of the tumor and the possibility of acute pancreatitis. The Santorini orifice was then re-approximated to the duodenal wall for protection against acute pancreatitis caused by scarring and stenosis of the duct orifice as a possible late complication. The patient's postoperative course was uneventful and she has been asymptomatic without evidence of tumor recurrence or stenosis of the Santorini orifice on endoscopic examination for the last 4 years.

Role of lumican in cancer cells and adjacent stromal tissues in human pancreatic cancer.

Lumican is a member of a small leucine-rich proteoglycan family and its overexpression has been reported in carcinoid tumor, breast, colorectal, neuroendocrine cell, uterine cervical and pancreatic cancers. The expression of lumican in stromal tissues in breast cancer is associated with a high tumor grade, a low estrogen receptor expression level and young age. Lumican expression in the cytoplasm in advanced colorectal cancer is correlated with a poor prognosis. Lumican expression was previously reported in pancreatic cancer, but the role of lumican in pancreatic cancer is still not well understood. In this study, we aimed to clarify the role of lumican in pancreatic cancer. Reverse-transcription polymerase chain reaction and Western blot analyses revealed lumican mRNA and protein expression in six pancreatic ductal adenocarcinoma cell lines (i.e. PANC-1, MIA PaCa-2, KLM-1, Capan-1, PK-1 and PK-8). On the basis of its immunoreactivity, lumican was found to be localized in islet cells of normal pancreatic tissues, but not in exocrine cells. In pancreatic cancer tissues, lumican was predominantly localized in the cytoplasm of cancer cells in 30 out of 53 (56.6%) cancer patients, whereas lumican was detected in stromal tissues in 36 out of 53 (67.9%) cancer patients. Lumican expression in pancreatic cancer cells did not correlate with clinicopathological factors, whereas lumican expression in stromal tissues correlated with the female gender, advanced stage, retroperitoneal and duodenal invasion and residual tumor (p=0.030, 0.038, 0.049, 0.049 and 0.048, respectively). Patients with lumican-positive cancer cells tended to survive longer than those with lumican-negative cancer cells (p=0.286), but patients with lumican-positive stromal tissues had shorter survival than those with lumican-negative stromal tissues (p=0.062). These results suggest that lumican in stromal tissues plays an important role in the growth and invasion of pancreatic cancer.

Enhanced expression of keratinocyte growth factor and its receptor correlates with venous invasion in pancreatic cancer.

Keratinocyte growth factor (KGF) and KGF receptor (KGFR) have been implicated in cancer growth as well as tissue development and repair. In this study, we examined whether KGF and KGFR have a role in human pancreatic ductal adenocarcinoma (PDAC). KGFR mRNA was expressed in eight pancreatic cancer cell lines, whereas the KGF mRNA was detected in seven of the cell lines and was absent in MIA PaCa-2 cells. KGFR and KGF immunoreactivity were localized in the cancer cells in 41.5 and 34.0% of patients, respectively. There was a significant correlation between KGFR or KGF immunoreactivity and venous invasion and a significant correlation between the presence of both markers and venous invasion, vascular endothelial growth factor (VEGF)-A expression, and poor prognosis. Exogenous KGF increased VEGF-A expression and release in MIA PaCa-2 cells, and PANC-1 cells stably transfected to overexpress KGF-exhibited increased VEGF-A expression. Moreover, short hairpin-KGFR transfection in MIA PaCa-2 cells reduced the stimulatory effect of exogenous KGF on VEGF-A expression. Short hairpin-KGF transfection in KLM-1 cells reduced VEGF-A expression in the cells. KGFR and KGF may act to promote venous invasion and tumor angiogenesis in PDAC, raising the possibility that they may serve as novel therapeutic targets in anti-angiogenic strategies in PDAC.