EXOCRINE PANCREATIC NEOPLASMS IN THE MUMMICHOG (FUNDULUS-HETEROCLITUS) FROM A CREOSOTE-CONTAMINATED SITE

A high prevalence of exocrine pancreatic neoplasms occurred in mummich og, Fundulus heteroclitus, from a creosote-contaminated site in the El izabeth River, Virginia. A total of 20 neoplasms were found in a group of about 1,300 fish obtained at this site over a 2-yr period. Of 240 fish collected during October 1991, 3.3% had pancreatic neoplasms. Adj usted total lesion prevalence for large adult fish (Size Class III: to tal length = 75-85 mm; Size Class IV: total length > 85 mm) was 6.7%. Pancreatic neoplasms were not observed in 234 fish collected at this s ite during May 1991, nor were they found in 420 fish obtained during f all 1991 from 1 uncontaminated and 6 moderately contaminated localitie s. Lesions involved both mesenteric and intrahepatic exocrine pancreas and ranged from well-differentiated acinar cell adenomas to poorly di fferentiated acinar cell carcinomas. One fish had an atypical acinar c ell focus. All specimens with pancreatic neoplasms also had hepatocell ular lesions. This epizootic of exocrine pancreatic neoplasia is the f irst to be reported in a wild fish population. Based on chemical chara cterization of the site and limited experimental data on chemically in duced pancreatic carcinogenesis in other small fish species, the neopl asms were probably caused by exposure of the mummichog to chemical car cinogens in their environment.