Shinsho Morita

Clinical study to identify specific characteristics of cancer newly developed in the remnant stomach.

Abstract.Abstract.Background: Cancer newly developed in the remnant stomach (CRS) after partial gastrectomy is worthy of attention not only because it is a typical model of carcinogenesis but also from the aspect of cancer diagnosis.Methods: We treated 47 patients with CRS in the 20 years from 1979 to 1998. Clinicopathological variables, as well as long-term survival results after the second surgery, were reviewed to clarify whether there were any differences in the characteristics of this disease entity compared with the usual primary gastric cancer.Results: The mean time interval between the initial surgery and surgery for CRS was 25.8 years for patients with CRS with previous benign gastric lesions, and 10.6 years for those with previous gastric cancer. CRS was frequently detected at an early stage in the patients with previous cancer, and in the patients who had undergone reconstruction by the Billroth I method (regardless of the primary nature of the disease). Cancers with a differentiated histology developed more frequently in the patients who had undergone the initial surgery for cancer disease. Long-term survival results after the second surgery clearly demonstrated that surgical treatment for CRS was as effective as that for primary cancer in the upper stomach (PUC). In addition, it was confirmed that new lymphatic drainage into the lower mediastinum or the jejunal mesentery had developed after the initial gastric surgery.Conclusion: The findings suggested that patients with CRS and those with PUC should be treated similarly, although the findings of a high incidence of lymph node metastasis to the lower mediastinum and/or to the jejunal mesentery in the CRS patients should be taken into consideration.

Pancreatic Schwannoma: Report of a Case

Among pancreatic neoplasms, pancreatic schwannoma is quite rare. We report a case of solitary pancreatic schwannoma, plus a literature review of this tumor. A 71-year-old woman was diagnosed by abdominal ultrasonography as having a pancreatic tumor and was hospitalized in our department at Kumamoto University Hospital on January 26, 2006. Abdominal computed tomography, magnetic resonance imaging, and endoscopic ultrasonography all showed this tumor, which was located in the body of the pancreas, to have cystic and solid components, and with a septum in the cystic part of the lesion. The tumor, preoperatively identified as a mucinous cystic neoplasm, was clearly separated from the normal pancreatic parenchyma. We performed a spleen-preserving distal pancreatectomy with a lymph node dissection on February 7, 2006. A histopathological examination of the resected specimen by means of hematoxylin and eosin revealed the tumor to consist of two parts: one with a compact spindle cell pattern (Antoni type A), and the other showing degeneration of fat (Antoni type B). We also found positive results for immunohistochemical staining for S-100 and vimentin. These findings confirmed the tumor’s classification as a pancreatic schwannoma.

The significance of proliferating cell nuclear antigen (PCNA) expression in cancer of the ampulla of vater in terms of prognosis.

Seventeen patients with cancer of the ampulla of Vater were studied retrospectively using immunohistochemical staining with a monoclonal antibody to the proliferating cell nuclear antigen (PCNA). The relationships between the PCNA-positive rate, being the number of PCNA-positive cancer cells to total cancer cells, the clinicopathological findings, and the clinical course were evaluated. The PCNA-positive rate in patients with lymph node metastasis (47%) was significantly higher than that in patients without metastasis (29%), while that in patients with advanced cancer invading the pancreatic parenchyma (47%), was significantly higher than that in patients with early cancer without invasion of the sphincter of Oddi (32%). All of five patients with early cancer are still alive, whereas five with semi-advanced cancer invading the sphincter of Oddi but not the pancreatic parenchyma, and two with a PCNA-positive rate of over 40% died of recurrent cancer. Of seven patients with advanced cancer, only one with a low PCNA-positive rate of 23% is alive, but the other six with a PCNA-positive rate of over 40% all died. The results suggest that the PCNA-positive rate provides a prognostic index for cancer of the ampulla of Vater.

Clinical problems in the surgical treatment of pancreaticobiliary maljunction

The results of surgical treatment of pancreaticobiliary maljunction at our department are described. The 67 patients who underwent surgery for this disease were divided by age into an adult group (45 patients, aged 16 years and over) and a pediatric group (22 patients, aged less than 16 years). The incidence of concomitant carcinoma before surgery and the incidence and severity of postoperative cholangitis were compared between these two groups. In addition, the cell proliferating activity of the biliary tract epithelium in cancer-free patients was compared between the two groups, using the proliferating cell nuclear antigen labeling index (PCNA LI). Ten patients (all adults) were diagnosed with cancer (gallbladder carcinoma in 7 and bile duct carcinoma in 3) before surgery. The surgical techniques used for reconstruction in the cancer-free patients were: in the adult group, hepaticoduodenostomy in 9 patients, Roux-en-Y hepaticojejunostomy in 17, jejunal interposition in 8, and another technique in 1. In the pediatric group, hepatico-duodenostomy was performed in 17 patients. Roux-en-Y hepaticojejunostomy in 3, and jejunal interposition in 2. Postoperative cholangitis occurred in 6 adults (including 2 with severe form) and 1 child (mild case). The PCNA LI of the biliary tract epithelium was high compared to control findings in the biliary tract epithelium of 10 adult patients without pancreaticobiliary maljunction. In the adult group with dilated extrahepatic bile ducts (n=10 examined) this index was 11.4% for the bile duct epithelium (control, 1.5%) and 12.7% for the gallbladder epithelium (control, 1.4%). In the adult group with non-dilated extrahepatic bile ducts (n=5 examined) it was 5.9% for the bile duct epithelium and 13.1% for the gallbladder epithelium. In the pediatric group (n=10 with extrahepatic bile duct dilatation) it was 7.5% for the bile duct and 9.7% for the gallbladder epithelium. (Differences from control values were all significant.) These results suggest that surgery for this disease should be performed as early as possible and that extrahepatic bile duct excision and biliary reconstruction should be performed whether or not extrahepatic bile ducts are dilated.

Diagnosis and Surgical Indications for Polypoid Lesions of the Gallbladder

To clarify the surgical indications for polypoid lesions of the gallbladder (PLG), we studied 62 patients who underwent cholecystectomy with the preoperative diagnosis of PLG. This included cholestero