Hepatic neoplasms in the mummichog Fundulus heteroclitus from a creosote-contaminated site.

High prevalences of idiopathic hepatic lesions were found in mummichog, Fundulus heteroclitus, from a site in the southern branch of the Elizabeth River, VA, contaminated with polycyclic aromatic hydrocarbons. Grossly visible hepatic lesions occurred in a total of 93% of the individuals from this site and 33% of these fish had hepatocellular carcinomas. Hepatic lesions were not detected in fish from two less contaminated sites. Lesions included foci of cellular alteration, hepatocellular adenoma, early and advanced hepatocellular carcinomas, and cholangiocellular proliferative lesions. Advanced carcinomas exhibited several distinct cellular patterns and some livers contained multiple neoplasms occupying up to 80% of the hepatic parenchyma. Sediments from the contaminated site contained extremely high concentrations (2200 mg/kg dry sediment) of polycyclic aromatic hydrocarbons, which are believed to originate from an adjacent wood treatment facility that has used creosote. Concentrations were 730- and 35-fold higher than those at the two other sites. These findings indicate a strong positive association between exposure to creosote-contaminated sediments and the high prevalence of hepatic neoplasms in a feral population of mummichog and support the putative role of polycyclic aromatic hydrocarbons in fish hepatocarcinogenesis. Additionally, they suggest that the mummichog may be a useful indicator of exposure to carcinogens in aquatic environments.