Focal Sinusoidal Obstruction Syndrome Caused by Oxaliplatin-Induced Chemotherapy: A Case Report

Abstract

IntroductionSinusoidal obstruction syndrome (SOS) is a severe adverse event of long-term chemotherapy in patients with colorectal cancer. It usually develops as liver congestion due to diffuse microscopic obstruction in liver parenchyma. In contrast, it sometimes appears as a liver mass occurring with local parenchymal hemorrhaging, and is often misdiagnosed as liver metastasis.Case PresentationA 40-year-old woman with rectal cancer underwent high anterior resection and partial liver resection of segment 7 due to synchronous liver metastasis. She received oxaliplatin-based chemotherapy (mFOLFOX6) as adjuvant chemotherapy for 6 months. A 13-mm irregular low-echoic mass was detected by CT in segment 3 of the liver 12 months after the operation. The mass was again resected as a liver metastasis because it had increased in size. The pathological diagnosis was focal SOS, which showed sinusoidal dilation and congestion by hepatocyte trabeculae in the liver parenchyma.ConclusionsAtypical irregular tumors should be considered as SOS when the patient has received oxaliplatin-based chemotherapy. A qualitative imaging modality diagnosis, such as with diffusion-weighted MRI, is superior to a morphological diagnosis in focal SOS. This imaging modality can prevent unnecessary operations.

FDG-PET/CT imaging findings of hepatic tumors and tumor-like lesions based on molecular background

“…SOS has no glycometabolism and thus shows no uptake of FDG, which is obvious considering the pathological findings. Uncommonly, SOS appears as a nodular lesion [119,120], in which case FDG-PET/CT imaging is useful to distinguish focal SOS from hepatic metastases combined with CT and MR images ( Fig. 20), especially in patients who are contraindicated for percutaneous liver biopsy.…”

Oxaliplatin-Induced Sinusoidal Obstruction Syndrome Masquerading as Colorectal Liver Metastasis: A Case Report

“…On dynamic study, approx 90% of the metastatic lesions present peripheral rim enhancement during the arterial and portal phases, which is usually not present in chemotherapy induced sinusoidal injury. Several other imaging features of a newly developed liver lesion which favour chemotherapy-induced focal sinusoidal injury, rather than metastasis are: iso intense on T1-weighted images [hypo intense in metastasis]; iso intense on T2-weighted images [hyper intense in metastasis]; iso intense on diffusion weighted images [hyper intense in metastasis].Qualitative imaging modalities like diffusion weighted MRI have superior diagnostic power than morphologic imaging modalities like CT or US [19]. Positron emission tomography CT shows no abnormal uorodeoxyglucose [FDG] uptake suggestive of malignancy [20].…”

Histopathological and biochemical assessment of liver damage in albino Wistar rats treated with cytotoxic platinum compounds in combination with 5-fluorouracil

“…Light microscopy (group F) showed sinusoidal dilatation and hemorrhage along with coagulative necrosis. In 5-FU and oxaliplatin treated CRC patients, such sinusoidal obstructive syndrome (SOS), presenting as metachronous pseudotumor with unclear hypodense mass, mimics CRC metastasis and can be mistaken for it [29]. Pathogenesis of SOS induced by 5-FU and oxaliplatin in rodents is described by activation of th coagulation cascade, direct release of increased number of platelets into the circulation associated with elevated vWF expression and upregulated expression of factor X transcript in the animal liver [30].…”