Splenic spread and hepatic encephalopathy in metastatic malignant melanoma.

An older adult patient was admitted with epigastric pain and vomiting and found to have an abdominal mass, increased cholestatic liver enzymes and markedly elevated serum lactate dehydrogenase (LDH). Imaging revealed extensive liver metastases of unknown primary but also an unusual splenic metastasis diagnosed by liver biopsy as malignant melanoma. The patient became lethargic and developed mental status changes associated with asterixis, abnormal EEG, and increased serum ammonia levels. All reversed with high-dose lactulose and had no alternative explanation other than an unusual hepatic encephalopathy secondary to portosystemic shunts bypassing the extensively metastatic liver.