Primary pancreatic lymphoma: report of six cases.

AIM: To heighten recognition of primary pancreatic lymphoma (PPL) in clinical practice.
METHODS: A retrospective review of the clinical presentation, imaging characteristics and pathological features of PPL patients were presented, as well as their diagnosis and treatment, in combination with literature review.
RESULTS: Histological diagnosis was made in four patients by surgery and in two patients by EUS-FNA. The six PPL patients (5 males and 1 female; age range, 16-65 years; mean age, 46 years) had the duration of symptoms for two weeks to three months. The primary presenting symptoms, though not characteristic, were abdominal pain, abdominal masses, weight loss, jaundice, nausea and vomiting. One of the patients developed acute pancreatitis. In one patient, the level of serum CA19-9 was 76.3 microg/L. Abdominal CT scan showed that three of the six tumors were located in the head of pancreas, two in the body and tail, and one throughout the pancreas. Diameter of the tumors in the pancreas in four cases was more than 6 cm, with homogeneous density and unclear borders. Enhanced CT scan showed that only the tumor edges were slightly enhanced. The pancreatic duct was irregularly narrowed in two cases whose tumors were located in the pancreatic head and body, in which endoscopic retrograde cholangiopancreatography (ERCP) showed that the proximal segment was slightly dilated. Two patients underwent Whipple operation, one patient underwent pancreatectomy, and another patient underwent operative biliary decompression. PPL was in stage I E in 2 patients and in stage II E in 4 patients according to the Ann Arbor classification system. The diagnosis of B-cell non-Hodgkin's lymphoma was made in all patients histopathologically. All six patients underwent systemic chemotherapy, one of whom was also treated with gamma radiometry. One patient died two weeks after diagnosis, two patients lost follow-up, two patients who received chemotherapy survived 49 and 37 mo, and the remaining patient is still alive 21 mo, after diagnosis and treatment.
CONCLUSION: PPL is a rare form of extranodal lymphoma originating from the pancreatic parenchyma. Clinical and imaging findings are otherwise not specific in the differentiation of pancreatic lymphoma and pancreatic cancer, which deserves attention. EUS-guided fine-needle aspiration (EUS-FNA) of the pancreas requires experienced cytopathologists as well as advanced immunohistochemical assays to obtain a final diagnosis on a small amount of tissue. Surgery and adjuvant chemotherapy or radiotherapy can produce fairly good outcomes.