Factitious hyponatremia in a patient with cholestatic jaundice following bone marrow transplantation.

We report a case of factitious hyponatremia in a boy who had received a bone marrow transplant for acute myeloid leukemia. Following transplantation, he developed graft-versus-host disease and obstructive jaundice. The pseudohyponatremia was found to be due to hyperlipidemia, but there were some unusual features. The patient's plasma triglyceride concentration was not significantly raised, but he had an extremely elevated cholesterol concentration, probably due to the presence of lipoprotein-X. His plasma, when first separated at room temperature, was icteric and relatively clear but developed a dense turbidity on being frozen at -20 degrees C.