Malignant Portal Vein Thrombus Research Articles

Rule of 15: A New Diagnostic Tool to Differentiate Benign and Malignant Portal Vein Thrombus

Rule of 15: A New Diagnostic Tool to Differentiate Benign and Malignant Portal Vein Thrombus

Differentiation of Malignant from Benign Portal Vein Thrombi on CT Images Using Thrombus Density

AbstractBackground: Portal vein thrombosis described as the presence of a clot in the portal vein lumen or a permanent obliteration of the portal vein as a result of prior thrombosis with replacement by numerous tortuous venous channels (termed cavernoma). Malignant portal vein thrombus, so named for its neoplastic origin, is a common complication of HCC, and, in some cases, it may be even the initial sign of an undetected HCC. Detection of malignant PVT in a patient with liver cirrhosis heavily affects the therapeutic strategy.Aim of Study: The purpose of this study was to investigate the role of CT thrombus density (measured in Hounsfield Units) in distinguishing between neoplastic and bland portal vein thrombosis on arterial and portal venous phases.Material and Methods: In this study, 30 patients underwent contrast-enhanced CT of abdomen & pelvis were included for characterization of portal vein thrombosis. Assessment of portal vein thrombosis was performed by measuring of CT attenuation values of the thrombi in Hounsfield Units (HU).ROC (Receiver Operating Characteristic) curves were used to identify accuracy and optimal cutoff values.Results: Of the 30 CT studies, 14 neoplastic thrombi and 13 bland thrombi were identified on the images. CT thrombus density (measured in Housinfield Unit) to differentiate neo-plastic from bland thrombus. The AUCs was 0.98 in arterial phase and 0.98 in portovenous phase for thrombus density.The optimal cut off in arterial phase is 47 and in porto-venous phase is 50.Conclusion: CT attenuation values allow reliable differ-entiation between neoplastic and bland thrombi on arterial and portal venous phase CT examination.

Discrimination between malignant and bland portal vein thrombosis: Could diffusion weighted MRI help

ObjectiveTo study the role of DWI in the differentiation between bland and malignant portal vein thrombus in HCC patients. Materials and methodsProspective study carried on 74 HCC patients with associated portal vein thrombus. Dynamic MRI examination and Diffusion imaging were performed for all patients. ADC values and ratios “ratio between the ADC value of HCC and ADC value of the thrombus” were calculated. We use at least two of the following criteria including the size of HCC more than 5 cm, the distance between the portal vein thrombus and the HCC less than 2 cm and the presence of enhancement within the thrombus, as a standard of reference to determine the nature of the thrombus. ResultsWe studied 74 patients; 55 patients diagnosed with malignant portal vein thrombosis and 19 patients diagnosed with bland portal vein thrombosis. We found that the ADC ratio with a cutoff value of 1.2 helped in discriminating the nature of the thrombus with 98% sensitivity and 70% specificity. There was no statistically significant difference in the ADC values of the benign and malignant thrombus. ConclusionDWI can determine the nature of the portal vein thrombus by measuring the ADC ratio between the tumour and the thrombus.

Diagnostic performances of intravoxel incoherent motion and conventional diffusion-weighted imaging in the differential diagnosis of benign and malignant portal vein thrombus.

To evaluate the diagnostic accuracy of intravoxel incoherent motion (IVIM) and diffusion-weighted imaging (DWI) parameters in the differential diagnosis of portal vein thrombus (PVT). Thirty-five patients with PVT were enrolled in this retrospective study. Precontrast axial in-phase and out-of-phase T1-weighted (W) turbo field echo (TFE), axial and coronal T2-W single-shot turbo spin echo, IVIM with b values between 0 and 1300s/mm2 andconventional DWI with b factors of 50, 400, and 800s/mm2 with single-shot echo-planar imaging, and postcontrast dynamic T1-W volumetric interpolated breath-hold examination images obtained with 1.5 T MR unit were evaluated. For quantitative analysis of conventional DWI, an ADC map was reconstructed from conventional DWI using all b values. For quantitative evaluation of IVIM, the SI was calculated from each b value. A specific software program was applied to calculate D (true diffusion coefficient), D* (pseudodiffusion coefficient associated with blood flow), and f (perfusion fraction). The differentiation between benign and malignant PVT was based on the criteria outlined in the study by Catalano et al. (Radiology 254:154-162, 2010). The ADC values of the malignant PVT were significantly lower than those of benign PVTs (p=0.005). Malignant PVTs had a tendency to show higher f values in comparison with benign PVTs without statistical significance (p=0.750). The best discriminative parameter was ADC values, which demonstrated a sensitivity of 80.0% and a specificity of 72.7% with cut-off value of 1.00×10-3mm2/s. ADC values might be more superior tool than IVIM parameters in differentiation between malignant and benign PVT.

Safety and Efficacy of Irradiation Stent Placement for Malignant Portal Vein Thrombus Combined with Transarterial Chemoembolization for Hepatocellular Carcinoma: A Single-Center Experience

PurposeTo assess feasibility, safety, and preliminary efficacy of an irradiation portal vein stent for portal vein tumor thrombosis (PVTT) in patients with hepatocellular carcinoma (HCC). Materials and MethodsBetween October 2012 and September 2015, 25 of 40 patients (mean age of 55.5 y) with PVTT caused by HCC were recruited for treatment with an irradiation portal vein stent (self-expandable stent loaded with iodine-125 seeds) at a single hospital. Liver function was classified as Child-Pugh class A in 15 patients (60%) and class B in 10 patients (40%). The Eastern Cooperative Oncology Group performance status score was 0 in 3 patients (12%), 1 in 13 patients (52%), and 2 in 9 patients (36%). Transarterial chemoembolization was performed after stent placement. Outcomes were measured in terms of technical success, complications, stent patency, and overall survival. ResultsThe technical success rate was 92.0% (23/25). No complications grade 3 or higher according to Common Terminology Criteria for Adverse Events were observed. Median stent patency period was 8.0 months (range, 0.6–30.0 months). Between 7 and 955 days after stent placement, 65 cycles of transarterial chemoembolization were performed with a mean of 2.8 cycles per patient. Median survival was 12.5 months (range, 0.6–35.7 months). ConclusionsPlacement of an irradiation portal vein stent appears feasible and safe and may prolong the patency of the portal vein. It is a promising technique for combining recanalization of an occluded portal vein and brachytherapy.

Interventional radiofrequency (RF) ablation as a therapeutic modality for patients with unresectable malignant pancreato-biliary and portal vein thrombus obstruction due to locally advanced malignancies

Interventional radiofrequency (RF) ablation as a therapeutic modality for patients with unresectable malignant pancreato-biliary and portal vein thrombus obstruction due to locally advanced malignancies

Diffusion-Weighted MRI of Malignant versus Benign Portal Vein Thrombosis.

ObjectiveTo validate the diffusion-weighted MRI (DWI) for differentiation of benign from malignant portal vein thrombosis.Materials and MethodsThe Institutional Review Board approved this retrospective study and waived informed consent. A total of 59 consecutive patients (52 men and 7 women, aged 40–85 years) with grossly defined portal vein thrombus (PVT) on hepatic MRI were retrospectively analyzed. Among them, liver cirrhosis was found in 45 patients, and hepatocellular carcinoma in 47 patients. DWI was performed using b values of 50 and 800 sec/mm2 at 1.5-T unit. A thrombus was considered malignant if it enhanced on dynamic CT or MRI; otherwise, it was considered bland. There were 18 bland thrombi and 49 malignant thrombi in 59 patients, including 8 patients with simultaneous benign and malignant PVT. Mean apparent diffusion coefficients (ADCs) of benign and malignant PVTs were compared by using Mann-Whitney U test. Diagnostic accuracy was evaluated using receiver operating characteristic (ROC) curve analysis.ResultsThe mean ADC ± standard deviation of bland and malignant PVT were 1.00 ± 0.39 × 10-3 mm2/sec and 0.92 ± 0.25 × 10-3 mm2/sec, respectively; without significant difference (p = 0.799). The area under ROC curve for ADC was 0.520. An ADC value of > 1.35 × 10-3 mm2/sec predicted bland PVT with a specificity of 94.6% (95% confidence interval [CI]: 84.9–98.9%) and a sensitivity of 22.2% (95% CI: 6.4–47.6%), respectively.ConclusionDue to the wide range and considerable overlap of the ADCs, DWI cannot differentiate the benign from malignant thrombi efficiently.

Ultrasound Guided Fine-Needle Aspiration Cytology (FNAC) of Portal Vein Thrombus: A Novel Diagnostic and Staging Technique for Occult Hepatocellular Carcinoma

Introduction: The diagnosis of Hepatocellular Carcinoma (HCC) is usually established using noninvasive radiological imaging and tumor markers. The stage at diagnosis is a critical factor in the treatment, course and prognosis of HCC. Patients with Tumor Portal vein thrombus (PVT) are considered to have an advanced disease and are only offered palliative therapy. Therefore, every possible attempt should be made to accurately stage HCC. Fine-needle aspiration cytology (FNAC) of PVT is an effective procedure for diagnosing and staging HCC. We present a case where we used Ultrasound (USG) guided FNAC of a PVT to successfully diagnose and stage HCC in the absence of a well-defined liver mass on imaging. Case report: A 43-year-old Hepatitis B surface antigen positive male presented with a 3-month history of fatigue, jaundice and fever. On examination he had hepatomegaly. His liver function tests were elevated, but his alpha-fetoprotein was normal. USG and Computed Tomography (CT) showed a thrombus in the portal vein but failed to show a well-defined liver lesion. FNAC was taken from the PVT, which was positive for malignancy. He was offered palliative chemotherapy and a steroid for his pyrexia. He is on follow-up. Conclusion: FNAC is a safe, quick, easy and economical technique to diagnose and stage HCC in the presence of portal vein thrombus, especially in patients where the tumor is occult on imaging. It also affords an accurate method to differentiate between malignant and nonmalignant PVT, thereby aiding appropriate therapeutic decision making.

Usefulness of Conventional MRI Sequences and Diffusion-Weighted Imaging in Differentiating Malignant From Benign Portal Vein Thrombus in Cirrhotic Patients

The objective of our study was to determine the value of diffusion-weighted imaging (DWI) and conventional MRI (non-DWI sequences) in differentiating benign portal vein thrombus (PVT) from malignant PVT in cirrhotic patients. A retrospective search of the department of radiology's MRI database of examinations performed from October 2006 through December 2010 for "portal vein thrombosis" and "cirrhosis" and "hepatocellular cancer" was performed. Patients who underwent diagnostic DWI and had thrombus shown to be rapidly (< 3 months) increasing in size despite anticoagulation therapy were considered to have malignant PVT (n = 16 cases) and patients with MRI findings showing stability or reduction in the extent of thrombus over a 12-month follow-up were considered to have benign PVT (n = 20 cases). Two blinded and independent reviewers analyzed the DW images and conventional MR images. There was no difference in the distribution of patients by age (p = 0.25) or sex (p = 0.68) between the benign and malignant PVT groups. On multivariate analysis, the only parameter to predict the type of PVT was the size of HCC (p = 0.05); other parameters were excluded from the model. There was substantial overlap in apparent diffusion coefficient (ADC) values and PVT/liver ADC ratios of benign PVT and malignant PVT. The presence of at least two of the three following MRI findings had a sensitivity of 100% and specificity of 90% for the diagnosis of malignant PVT: distance from tumor to PVT of less than 2 cm, HCC size of greater than 5 cm, and arterial enhancement of PVT. Signal-intensity characteristics on DWI and measured ADC values do not reliably differentiate benign PVT from malignant PVT. On the other hand, careful assessment of conventional MRI findings may allow this distinction, thus obviating biopsy.

Hepatocellular Carcinoma Presenting as an Incidental Isolated Malignant Portal Vein Thrombosis

Portal vein thrombosis is frequently associated with hepatocellular carcinoma (HCC). Tumor invasion into the portal vein by direct venous extension or metastasis occurs in up to 70% of HCC patients (Cedrone et al., Liver 16:94-8, 1996). However, presentation as an isolated malignant portal vein thrombosis without any evidence of obvious hepatoma-like lesions in the liver by imaging studies is extremely uncommon. We present an unusual case of HCC presenting as a malignant portal vein thrombus, proven on biopsy of the thrombus without any evidence of primary liver lesion. This, to our knowledge, is the first case of HCC presenting as an incidental isolated malignant portal vein thrombosis. The importance of doing delayed enhancement imaging studies to rule out malignant portal vein thrombosis is emphasized. A 60-year-old man presented with acute substernal chest pain. Physical examination revealed icterus. Examination of the abdomen did not reveal any organomegaly. Liver function test revealed a predominantly conjugated bilirubinemia. Abdominal sonogram revealed thrombosis and occlusion of the posterior right portal vein. Liver parenchyma was homogenous with no intrahepatic mass. Computed tomography (CT) of the abdomen and pelvis after administration of oral and intravenous contrast with delayed views revealed arterial enhancement of the right portal vein thrombus with delayed washout. MRI of the abdomen with gadolinium confirmed the right portal vein thrombus without focal hepatic mass. Aspiration of the right portal vein thrombus under CT guidance revealed hepatocellular carcinoma which was confirmed by immunohistochemistry. Serum alpha-fetoprotein level was very high. Patient was started on sorafenib with subsequent decrease in alpha-fetoprotein level. He was doing well till the date of this report. This unusual case of hepatocellular carcinoma presenting as an incidental malignant portal vein thrombosis without any primary liver lesion is extremely rare. Other reported cases of malignant portal vein thrombosis have been in patients with underlying hepatoma, cirrhosis, or with intrabiliary hepatocelluar carcinoma. In the clinical setting of portal vein thrombosis, imaging studies showing enhancement of the thrombus in the arterial phase are important in leading to the diagnosis of malignancy.

Highly metabolic thrombus of the portal vein: 18F fl uorodeoxyglucose positron emission tomography/computer tomography demonstration and clinical signifi cance in hepatocellular carcinoma

To assess the ability of (18)F-fluorodeoxyglucose positron emission tomography/computer tomography ((18)F-FDG PET/CT) to differentiate between benign and malignant portal vein thrombosis in hepatocellular carcinoma (HCC) patients. Five consecutive patients who had HBV cirrhosis, biopsy-proven HCC, and thrombosis of the main portal vein and/or left/right portal vein on ultrasound (US), computer tomography (CT) or magnetic resonance imaging (MRI) were studied with (18)F-FDG PET/CT. The presence or absence of a highly metabolic thrombus on (18)F-FDG PET/CT was considered diagnostic for malignant or benign portal vein thrombosis, respectively. All patients were followed-up monthly with US, CT or MRI. Shrinkage of the thrombus or recanalization of the vessels on US, CT or MRI during follow-up was considered to be definitive evidence of the benign nature of the thrombosis, whereas enlargement of the thrombus, disruption of the vessel wall, and parenchymal infiltration over follow-up were considered to be consistent with malignancy. (18)F-FDG PET/CT, and US, CT or MRI results were compared. Follow-up (1 to 10 mo) showed signs of malignant thrombosis in 4 of the 5 patients. US, CT or MRI produced a true-positive result for malignancy in 4 of the patients, and a false-positive result in 1. (18)F-FDG PET/CT showed a highly metabolic thrombus in 4 of the 5 patients. (18)F-FDG PET/CT achieved a true-positive result in all 4 of these patients, and a true-negative result in the other patient. No false-positive result was observed using (18)F-FDG PET/CT. (18)F-FDG PET/CT may be helpful in discriminating between benign and malignant portal vein thrombi. Patients may benefit from (18)F-FDG PET/CT when portal vein thrombi can not be diagnosed exactly by US, CT or MRI.

Characterization of Portal Vein Thrombus With the Use of Contrast-Enhanced Sonography

To select an appropriate treatment regimen, it is essential to accurately characterize the nature of a thrombus. This study prospectively assessed the ability of contrast-enhanced sonography to differentiate between benign and malignant portal vein thrombosis in a population of high-risk patients. Fifty-five patients (43 men and 12 women; mean age, 66 years; range, 55-83 years) with thrombi of the portal venous system were examined by power Doppler sonography and contrast-enhanced sonography with the intravenous contrast agent SH U 508A (Levovist; Schering AG, Berlin, Germany). Of the thrombi, 40 were characterized as malignant and 15 as benign. Pulsatile flow in the thrombus on power Doppler sonography and positive enhancement of the thrombus on contrast-enhanced sonography were judged as indications of a malignant thrombus. The sensitivity and specificity of both methods in differentiating the nature of the thrombus were evaluated. The detection of pulsatile flow in a portal vein thrombus as the criterion for diagnosing malignant portal vein thrombus yielded overall sensitivity of 82.5% and specificity of 100%, whereas positive enhancement of the portal vein thrombus itself as a criterion for diagnosing malignancy yielded overall sensitivity and specificity of 100% for each. Contrast-enhanced sonography can be helpful in discriminating between benign and malignant portal vein thrombi.