(Hepatology 2014;60:1789–1791) Sinusoidal obstruction syndrome (SOS) generally occurs within 3 weeks after myeloablative chemotherapy.[1, 2] The reported incidence ranges from 5% to 70% depending on the conditioning regimen and risk factors such as previous exposure
to cytotoxic agents.[1, 2] We report two patients with SOS treated with defibrotide in whom 18F-fluorodeoxyglucose positron emission tomography / computed tomography (FDG-PET/CT) demonstrated interesting findings. A 36-year-old man with brain tumor previously treated with chemotherapy followed by hematopoietic stem cell transplantation (HSCT) was investigated 2 months later by PET/CT scan, which revealed numerous disseminated lesions with increased FDG uptake Dinaciclib research buy in the liver corresponding to multiple hypodense lesions on CT, suggestive of metastases (standardized uptake value [SUV] peak = 2.7) (Fig. 1A). Clinical examination was normal. Laboratory work-up showed thrombocytopenia and slightly elevated transaminases (Table 1). Transjugular liver biopsy (TJLB) revealed SOS with moderate injury of sinusoidal endothelium
and dilatation of the sinusoids, no hepatocyte necrosis, and only mild fibrin deposition in hepatic venules. Treatment with defibrotide was initiated, according to the protocol recommended by our national multidisciplinary meeting for vascular disorders of the liver: defibrotide is available through a strictly regulated compassionate-use program. Once approved, treatment is authorized for 2 weeks at a dose of 6.25 mg per kg body weight, with the possibility to apply for longer use if treatment is effective. No improvement of laboratory Ku-0059436 concentration parameters was observed after 1
month of treatment. Follow-up PET/CT did not demonstrate any significant changes (Fig. 1B). Defibrotide was stopped and transaminases remained stable and slightly elevated. Thrombocytopenia did not improve and was attributed to chemotherapy-induced MCE dysmyelopoiesis. The patient died from brain herniation due to progression of the primary tumor 3 months after completion of defibrotide therapy. A 51-year-old man with a Hodgkin’s lymphoma presented with dyspnea and jaundice 2 weeks after HSCT. Clinical examination revealed significant hepatomegaly and anasarca. Laboratory work-up showed marked elevation of transaminases and bilirubin, thrombocytopenia and decreased clotting factors (Table 1). PET/CT showed diffusely increased hepatic activity (SUV peak = 3.3) (Fig. 1C). TJLB demonstrated SOS with severe destruction of sinusoidal endothelium, dilatation of the sinusoids (Fig. 2), hepatocyte necrosis, and obliterated hepatic venules. Treatment with defibrotide was initiated. Liver FDG uptake returned to normal after 1 month of treatment (SUV peak = 2.4, Fig. 1D), associated with complete clinical recovery and normalization of laboratory parameters. SOS should be suspected in postmyeloablative chemotherapy patients who develop hepatomegaly, jaundice, and weight gain.