Primary pancreatic lymphoma is a rare but treatable malignancy that may present as an isolated pancreatic mass. Most of these patients are assumed to have ductal malignancies of the pancreas and are denied surgical intervention. Controversy exists concerning the method of diagnosis and the need for and extent of surgical intervention for these malignancies. Over the past 15 years, from 1976-1991, we have treated seven patients with pancreatic lymphoma who initially presented with a pancreatic mass. There were five females and two males ranging in age from 60-86 years (mean = 68). All patients were symptomatic and complained of epigastric pain, jaundice, anorexia, or early satiety. The interval between onset of symptoms and treatment averaged 6 weeks. Over half of these patients presented with an epigastric mass and/or jaundice. Abdominal CT scan was accurate in identifying and localizing the pancreatic mass in all patients. The diameter of the pancreatic mass ranged from 3-12 cm (mean = 8.1 cm) and the mass was located in the head of the pancreas in five patients. All attempted percutaneous needle biopsies of the pancreatic mass were non-diagnostic. Operative lymph node biopsy or transduodenal/wedge biopsy of the pancreatic mass was successful in demonstrating pancreatic lymphoma in all patients. Two of the seven patients underwent biliary bypass. One of the seven patients died in the postoperative period. Three of these seven patients received chemotherapy and survived an average of 6.3 years. One patient is alive 8 years after diagnosis and treatment and is currently asymptomatic. Patients who did not receive postoperative chemotherapy survived an average of 5 months.(ABSTRACT TRUNCATED AT 250 WORDS)