Question: Sinusoidal obstruction syndrome, previously known as veno-occlusive disease is a feared complication of bone marrow transplantation, and typically occurs within 3 weeks after the transplant. Which of the following clinical parameters is not typical for making the diagnosis of SOS?
A. weight gain
B. mild hyperbilirubinemia
C. variceal bleeding
D. tender hepatomegaly
Answer: SOS involves the occlusion of hepatic sinusoids and terminal hepatic venules, and resembles Budd-Chiari Syndrome. It has many predisposing causes, including a variety of antineoplastic drugs, advanced age, elevated ALT pre-transplant, HBV, HCV, cirrhosis and allogenic (as opposed to autologous) bone marrow transplantation.
The diagnosis can often be made on clinical grounds alone, particularly when it occurs soon after transplant. Weight gain (reflecting ascites), tender hepatomegaly and mild jaundice are the classic triad. In severe cases, encephalopathy and multiorgan failure can occur; fortunately, the disorder resolves over 2 to 3 weeks with supportive care for most patients.
If you are really smart, you can probably explain why variceal bleeding can occur in the presence of SOS…given the development of portal hypertension. In fact, it has been described before in a pediatric patient. Variceal bleeding is not a cardinal feature of the disorder, so of all the answer choices, it is the least correct.