Malignant melanoma of the liver:a case report and review of literature

Objective:To investigate the diagnosis,differential diagnosis and biologic behaviors of primary malignant melanoma of the liver.Methods:A case of primary malignant melanoma of the liver was reported with clinicopathological analysis,immunohistochemistry and review of literature.Results:Grossly,there was a clear circumsciption between mass and liver tissues,with a intact capsule.Microscopically,the tumer cells were diffuse,and there was fibrous tissue between lesions and liver tissues,but a few tumor cells broke through the capsule and infiltrated into the liver tissues.The tumor cells were multi-pleomorphic,and they were round,spindle shaped and irregular.The tumor cell nucleus were round or oval,and the nucleoli were prominent with eosinophilic or basophilla.Some tumor cells were with melanin deposition of melanin pigment.Immunohistochemistry assay showed that the tumor cells were positive for HMB-45,Melanoma-pan,S-100 protein and Vimentin,and negative for AFP,High-MW-CK,CK18,CEA,CK19,CD34,CD117,NSE,LCA,CK,CHA,HCG,EMA,SCLC,Desmin,SM-actin,SC-actin,myoglobin and Syn.Conclusion:Primary malignant melanoma of the liver is a very rare neoplasm with many kinds of histological appearance.It should be considered as malignant melanoma when it is difficult to dignose for liver neoplasm.