Hepatic Sinusoidal Obstruction Syndrome Secondary to Aplastic Anemia/Paroxysmal Nocturnal Hemoglobinuria Syndrome: A Rare Case

Paroxysmal nocturnal hemoglobinuria (PNH) is associated with bone marrow failure disorders and may arise during the long-term follow-up of aplastic anemia (AA), which is named AA/PNH syndrome. Thrombosis is the most frequent clinical complication and is the main cause of mortality in PNH. However, thromboses tend to originate in hepatic and cerebral venous vessels, but rarely in the hepatic microvascular vein in PNH patients. Here, we report on a young man with hepatic sinusoidal obstruction syndrome (HSOS) secondary to AA/PNH syndrome. His main manifestations were hemolytic anemia, renal injury, ascites, hepatomegaly, and elevated liver enzymes. The diagnosis was confirmed by peripheral blood flow cytometry, enhanced computed tomography (CT), and liver biopsy. Initially, he received symptomatic treatments including diuretics, intermittent abdominal paracentesis, and low-molecular-weight heparin. Meanwhile, due to the occurrence of PNH activity during hospitalization, methylprednisolone 40 mg per day was administered, which was later transitioned to oral prednisolone. Subsequently, the dose of corticosteroids was gradually decreased once his hemoglobin stabilized. The association between HSOS and AA/PNH syndrome is exceptionally rare, as evidenced by the scant literature on the subject. This case underscores the critical need for awareness of HSOS secondary to AA/PNH syndrome, which needs a high index of suspicion and for which prompt treatment is needed to reduce morbidity and mortality.