Objective.To in vestigate clinicopathologic characteristics and surgical results of nonfunctiona l islet cell tumors.Methods.We performed retrospective analysis of50patient s with nonfunctional islet cell tumor treat-ed at Peking Union Medical College Hospital from July1968to July1999

and summarized clinical symptoms and signs

primary diagnosis before surgery

surgical treatments

pathologic and im munohisto-logical characteristics.Results.Of the50cases examined from July 1968to July1999

12were found during physical examinations. The most common symptoms were upper abdominal pain and upper abdominal dis-com fort

which appeared in20casesand17casesrespectively

an d the most common sign was abdominal masses.B-ultrasound and CT are the most commonly used means for preoperative examination

with posit ive rates of97.8%and100%respectively.Op-e rative mortality was2%.Five-year survival rate of radical surgery of maligna nt cases was75%.Immuno-histological examinations showed that tumors rich i n multi-peptide linked hormones

neuron-specific eno-lase and chromaffin were in65%cases

90.6%and73.3% respectively.The positive rates of insulin

glucagons

somatostatin

pancreat ic polypeptide

gastrin and vasoactive intestinal peptide were68.2%

51.2%

42.9%

40%

25%and15.8%respectively.Conclusion.Nonfuncti onal islet cell tumors lack diagnostic specificity.Ultrasound and CT are primar y examination methods.Immunohistological analysis indicates different hormones

but lacks the presence of related clinical symptoms.Surgery is an effective treatment for nonfunctional islet cell tumors

and even for those with distal m etastasis

immediate surgical removal and treatment can improve prognosis.