Clinical and Immunohistochemical Characteristics of Pancreatic Neuroendocrine Tumor: Immunohistochemical Analysis of 7 Tumors

BACKGROUND: Neuroendocrine tumors of the pancreas are classified according to the endocrine function as insulinomas gastrinomas somatostatinomas, or nonfunctioning tumors. However, the morphologic features are not different from each other. Therefore, we tried to compare correlations among the morphologic features, endocrine function, and the immunohistochemical reaction with specific monoclonal antibodies to the tumors. METHOD: We reviewed the medical records of seven patients with pancreatic neuroendocrine tumors retrospectively, and analysed the clinical manifestations, the methods of diagnosis, the pathological characteristics and the results of surgery. Additionally, we compared the correlation between the clinical manifestations and the expression of immunohistochemical staining by using six different kinds of monoclonal antibodies to each tumor. RESULTS: The seven pancreatic neuroendocrine tumor patients were treated by surgical excision. Four patients had benign insulinomas, two had nonfunctioning malignant tumor and one patient had a benign nonfunctioning tumor associated with stomach cancer. The pattern of immunohistochemical stain of each tumor was not correlate with the clinical manifestations. CONCLUSION: The morphologic study with H & E stain, even with immunohistochemical staining of pancreatic neuroendocrine tumor, cannot support differentiation of the functional diagnoses, such as insulinoma, gastrinoma, somatostatinoma, nonfunctional tumors and so forth.

A Clinical Study of Adult Aortic Stenosis Treated with Aortic Valve Replacement

BACKGROUND: Significant aortic stenosis of various underlying etiologies presents with similar clinical characteristics and is usually treated with aortic valve replacement. We performed a clinical study to evaluate the clinical characteristics, changes of echocardiographic parameters before and after aortic valve replacement in adult aortic stenosis patients. METHODS: From January 1991 through December 1995, 159 patients underwent aortic valve replacement at Sejong General Hospital. Sixty-two cases(39%) of those patients were pure or predominant aortic stenosis. We observed the clinical characteristics, etiology, operative procedure, perioperative complication and mortality, And we observed the changes of echocardiographic parameters such as mean and peak pressure gradients at aortic valve, ejection fraction, systolic and diastolic left ventricular internal dimensions, left ventricular wall thickness, left ventricular mass index retospectively at preoperative and postoperative periods regularly within 1 month, 1 yr, 3 yrs after operation(mean follow up period : 16 months, 1-36 months). RESULTS: 1) The age of patients ranged from 31 to 71 years(mean 55+/-11), and 60%(37 cases) of them were men. 2) Regarding underlying heart disease, the most common etiology of aortic stenosis was rheumatic valvular heart disease(32 cases, 52%), followed by congenital bicuspid aortic valve(16 cases, 25%) and degenerative change(14 cases,23%). 3) 44 cases(77%) of the patients had dyspnea,12 cases(19%) had chest pain, and 5 cases(8%) had history of syncope at the time of operation. Asymptomatic patient was only 1 case. 4) Seven patients(11%) had associated coronary artery disease, and only 1 case(about 2%) underwent concomitant coronary bypass surgery. 5) Post-operative complications which developed within 1 month were bleedings(8 cases, 13%), arrhythmias(7 cases, 11%) and infections(4 cases, 6%). After 1 month, bleedings related with anticoagulation were most common(7 cases, 11%). Other complications were hemolytic anemia(1 case), and aortic dissection(1 case). There was one surgery related mortality(2%) which happened during operatin due to myocardial ischemia. 6) The size of implanted prosthetic valves ranged from 19 to 25mm(mean 22+/-2mm). Larger valves(23-25mm) showed lower peak(p=0.839) and mean pressure gradients(p=0.019) than smaller valves(19-21mm). 7) We observed that peak and mean pressure gradient, left ventricular internal dimension, and left ventricular mass index had decreased significantly after aortic valve replacement. 8) The average preoperative functional class(2.3) had improved significantly at 1 month after surgery(1.2), and 1 year after surgery(1.0). CONCLUSIONS: In our series, the most common etiology of aortic stenosis was rheumatic valvular disease(52%). The incidence of combined coronary artery disease was 11%, lower than other reports. And only 1 case(2%) underwent concomitant coronary artey bypass graft surgery. The average size of implanted valves was 22mm, and the larger size had lower transaortic peak and mean pressure gradients after operation. The most common perioperative complication was bleeding and mortality rate was about 2%. Echocardiography was useful for evaluation of postoperative changes, such as transaortic peak and mean pressure gradient, left ventricular internal dimension and left ventricular mass index.