Cholangioma in white perch (Morone americana) from the Chesapeake Bay.

Cholangiomas found in two of 21 wild-caught white perch (Morone americana) from the Chesapeake Bay are described. The two fish were part of a study investigating a condition of abnormal hepatic copper storage in this species. The tumors were superficial, solitary masses consisting of cuboidal to columnar cells in tubuloglandular arrangement. Mild to marked peribiliary inflammation and fibrosis was seen also. Environmental pollution, the condition of abnormal copper storage, peribiliary fibrosis, and/or parasites may have contributed to the development of these tumors.