Hyperammonemic encephalopathy in a patient with primary hepatic neuroendocrine carcinoma

A 53-year-old male patient was admitted to our hospital with abdominal pain in the right upper quadrant. There was no change in laboratory investigations other than a slight increase in serum levels of alkaline phosphatase (ALP), alanine aminotransferase (ALT), and gamma glutamyl transferase (GGT). Computed tomography (CT) of the abdomen showed multiple hepatic nodular lesions in the liver. Tru-cut biopsy of the lesions was reported as well-differentiated neuroendocrine carcinoma. The patient received sandostatin treatment. After a few days, the patient was hospitalized in the intensive care unit with disturbance of consciousness and clinical features suggestive of encephalopathy. Serum ammonia level was found highly elevated. After the treatment with L-ornithine-L-aspartate, a remarkable improvement in the level of patient's sensorium occurred as well as a reduction in serum ammonia level within a few days. Transarterial chemoembolization (TACE) was performed one week later. The patient's condition began to worsen along with increase in serum ammonia level and he died because of hyperammonemic encephalopathy. There are case reports of hyperammonemia with some malignancies such as multiple myeloma, plasma cell leukemia, and leiomyosarcoma, or in some patients who have received chemotherapy. This case may suggest an association between hyperammonemia and neuroendocrine tumors.