ACINAR CELL-CARCINOMA OF THE PANCREAS - REPORT OF 3-CASES

Pancreatic acinar cell carcinoma is a rare neoplasm (comprising about 1% of pancreatic tumours). We studied three cases (61-year-old female; 42-year-old male; 57-year-old male), whose survival after diagnosis r anged from 1 year 2 months to 6 years 8 months. There were widespread metastases in each case. The tumours had acinar, trabecular and solid growth patterns. By immunohistochemistry, pancreatic acinar cell marke rs including carboxyl ester lipase, pancreatic secretory trypsin inhib itor and pancreatic phospholipase A(2) (group I PLA(2)) gave a strong positive reaction in all three cases. By electron microscopy, zymogen granules were seen in the cytoplasm of the tumour cells. Immunostainin g for prostate-specific antigen was positive in all three cases. Above -normal concentrations of pancreatic PLA(2) were measured in the serum of one patient and the values decreased during chemotherapy concomita ntly with the reduction in the size of the tumour mass. In conclusion, immunohistochemical demonstration of the secretory products of acinar cells including the new marker pancreatic PLA(2) is useful in the dif ferential diagnosis of pancreatic acinar cell carcinoma. Determination of the concentration of pancreatic group I PLA(2) in serum may be hel pful in the evaluation of therapy.