Abstract: This research aimed to diagnose a case of liver melanoma that happened in a broiler chicken. A 25-day-old broiler chicken was observed depressed and extremely thin, and the whole liver was black at autopsy. Hematoxylin and eosin (HE) staining results show a large amount of abnormal cells with different sizes, hyperchromatic nuclei and severe melanin granules deposition in the diseased liver. Immunohistochemistry of the liver incubated with both SOX 10 and HMB-45 antibody show positive results. Based on the results of the pathological and immunohistochemical examination, the broiler chicken was diagnosed with serious liver malignant melanoma. Results of both bile pigment and Prussian blue staining were negative, suggesting that the liver lesion was not caused by bilirubin or hemosiderin deposition. In summary, based on the results of differential diagnosis, the broiler chicken was diagnosed with serious liver malignant melanoma. Results of the present study help to provide reference for the diagnosis of avian melanoma in poultry.

Key words: broiler chicken, liver, melanoma, pathological diagnosis