Small hepatocellular carcinoma: diagnosis with US angiography with intraarterial CO2 microbubbles

Inflammatory pseudotumor of the liver in a patient with chronic hepatitis C: difficulty in differentiating it from hepatocellular carcinoma

A case of an inflammatory pseudotumor of the liver in a 75-year-old female with chronic hepatitis C whose radiologic features simulated that of hepatocellular carcinoma (HCC) is presented. On imaging studies, hypervascularity by CO2 ultrasound (US) angiography, enhancement at an early phase and isodensity at a late phase by incremental dynamic computed tomography (CT), perfusion defect by CT during arteriography (CTAP), and clinical background of hepatitis C virus (HCV) infection strongly suggested HCC. A US-guided needle biopsy revealed a mainly diffuse and polyclonal proliferation of lymphocytes positive for leukocyte common antigen (pan-lymphocyte cells), L-26 (B cell lymphocytes), and UCHL-1 (T cell lymphocytes), negative for both kappa and lambda light chains and sparsely distributed neutrophils and histiocytes. No lymphoid follicles were observed. The liver tissue around this tumor showed chronic hepatitis with mild activity and mild fibrosis. These histopathologic findings suggested that the diagnosis of inflammatory pseudotumor of the liver was tenable. As it is difficult to differentiate between inflammatory pseudotumor of the liver and HCC by imaging studies alone, supplemental biopsy, where possible, should be obtained when diagnostic imaging of tumors suggesting HCC is carried out. We emphasize that histopathology is a true gold standard in the diagnosis of this disease.

Vascularization of small hepatocellular carcinomas: correlation with differentiation

BACKGROUND

Hepatocellular carcinoma (HCC) is generally considered a hypervascular tumor when visualized by angiography. However, small HCCs are not always found to be hypervascular.

METHODS

To evaluate this, 50 HCCs < or =3 cm in diameter were studied. The 50 tumors consisted of 16 well-differentiated HCCs, 25 moderately differentiated HCCs, and 9 that were each a mixture of well- and moderately differentiated HCC.

RESULTS

The mean number of portal tracts in the well-differentiated HCCs was 34% of the number in the surrounding nontumorous liver, and few intratumoral arterioles were seen. In contrast, the mean number of portal tracts in the moderately differentiated HCCs was 0.6% of the number in the surrounding nontumorous liver, and abundant intratumoral arterioles were seen. For HCCs that contained both well-differentiated and moderately differentiated tumor, the distribution of portal tracts and intratumoral arterioles in each portion was similar to that seen in well-differentiated or moderately differentiated HCC alone, respectively. HCCs that were larger than 1.5 cm in diameter had fewer portal tracts and more intratumoral arterioles than HCCs whose diameters were < or =1.5 cm.

CONCLUSIONS

As small HCCs increase in size and become increasingly dedifferentiated, the number of portal tracts apparently decreases and intratumoral arterioles develop. These findings may reflect changes in the hemodynamics as the HCC develops.

Clinical utility of Lens culinaris agglutinin-reactive alpha-fetoprotein in small hepatocellular carcinoma: special reference to imaging diagnosis

BACKGROUND/AIMS

Blood concentration levels of alpha-fetoprotein like the Lens culinaris agglutinin-reactive fraction (AFP-L3) are a useful marker for predicting the long-term prognosis of hepatocellular carcinoma. This study investigated the relationship between serum AFP-L3 and various imaging modalities.

METHODS

Sixty-three patients with small hepatocellular carcinomas < or = 2 cm in diameter were studied. Serum AFP-L3 concentrations were measured by lectin-affinity electrophoresis coupled with antibody-affinity blotting and expressed as % AFP-L3 (the percent of AFP-L3 as total AFP). A clinical "cutoff level" of 10% was used in this study to indicate the presence of hepatocellular carcinoma. Selective hepatic intraarterial digital subtraction angiography (DSA), ultrasonographic angiography with carbon dioxide microbubbles (USAG), and computed tomography during arterial portography (CTAP) were performed to evaluate the hemodynamics of hepatic nodules.

RESULTS

Fourteen (22.2%) of the 63 patients were positive for % AFP-L3. The % AFP-L3 levels (n=45, 4.4%) of patients with hypervascular tumors were significantly higher than those (n=15, 0.0%) of patients with isovascular or hypovascular tumors as determined by USAG (p=0.0061). The % AFP-L3 levels (n=53, 4.4%) of patients with a negative portal blood supply were significantly higher than the % AFP-L3 levels (n=7, 0.0%) of patients with a positive portal blood supply as determined by CTAP (p=0.0140). The % AFP-L3 levels of patients with tumors with a long doubling time (DT) were significantly lower than for patients with tumors with a short DT (p=0.0176).

CONCLUSION

AFP-L3 is a positive indicator which may be more specific for small advanced hepatocellular carcinoma.

Power Doppler imaging of hepatic tumours: differential diagnosis between hepatocellular carcinoma and metastatic adenocarcinoma

We evaluated the usefulness of power Doppler imaging in the differential diagnosis between hepatocellular carcinoma and metastatic adenocarcinoma. Forty-seven patients with hepatocellular carcinoma and 18 patients with metastatic adenocarcinoma were evaluated using power Doppler imaging. The colour signals of hepatic tumours were graded as follows: 1, colour signals only in the marginal area; 2, small dot or dotted line colour signals within the tumours; 3, continuous solid line colour signals within the tumours. The grade 3 colour signals were classified in the following three patterns; winding line pattern, stretched line pattern and mixed pattern. The colour signals of hepatocellular carcinoma were grade 1 in seven patients, grade 2 in 11 and grade 3 in 29. The colour signals of metastatic adenocarcinoma were grade 1 in three patients and grade 3 in 15. Of the 29 hepatocellular carcinoma patients with a grade 3 signal, 26 patients had winding line patterns and three had mixed patterns. Of the 15 metastatic adenocarcinoma patients with a grade 3 signal, 12 patients had stretched line patterns and three had mixed patterns. In conclusion, power Doppler imaging is useful in the differential diagnosis between hepatocellular carcinoma and metastatic adenocarcinoma to evaluate the colour signal pattern within the tumour.

Intra-arterial carbon dioxide-enhanced ultrasonogram of hepatocellular carcinoma treated by transcatheter arterial embolization and percutaneous ethanol injection therapy

The purpose of this study was to investigate the value of carbon dioxide-enhanced ultrasonography (CO2-US) in the evaluation of viable hepatocellular carcinomas (HCC) which were treated by transcatheter arterial embolization (TAE), percutaneous ethanol injection (PEI), or a combination treatment (TAE and PEI). Forty-one patients with 66 HCC were included in the study. They underwent CO2-US and angiography were performed in all tumours after they were treated by TAE, PEI or a combination treatment. Forty-six tumours were positively enhanced by CO2-US and 40 of them were positive by angiography. These 46 tumours were proved to be viable tumours either by biopsy or by follow-up studies. The positive predictive value was 100% for CO2-US and 87.8% in angiography. Twenty tumours were negative by CO2-US and these were also negative by angiography. Carbon dioxide-enhanced ultrasonography is a more reliable method for detecting the viable portion of the treated HCC compared with conventional angiography.

Changes in blood supply in small hepatocellular carcinoma: correlation of angiographic images and immunohistochemical findings

BACKGROUND/AIMS

To assess the changes occurring in blood flow with growth in small hepatocellular carcinomas, we analyzed the angiographic features and immunohistochemical findings in 35 hepatocellular carcinomas less than 2 cm in diameter.

METHODS

Hepatocellular carcinomas were evaluated by digital subtraction angiography (DSA), ultrasound angiography with intraarterial CO2 microbubbles (USAG), and computed tomography during arterial portography (CTAP). Immunohistochemically, hepatocellular carcinomas were evaluated using QB-end/10 (QB) monoclonal antibody.

RESULTS

All 18 moderately-differentiated hepatocellular carcinomas stained positively with QB antibody. No hepatocellular carcinomas without attenuation on CTAP were positive by immunohistochemistry, and two hepatocellular carcinomas with attenuation on CTAP also lacked staining. We observed four hepatocellular carcinomas without hypervascularity on DSA or USAG, which stained positively with QB antibody; these hepatocellular carcinomas had fatty metamorphosis.

CONCLUSIONS

1. Immunohistochemical findings are closely associated with angiographic findings regarding changes in blood supply. 2. All moderately-differentiated hepatocellular carcinomas have characteristics of hypervascularity, both by angiographic images and by immunohistochemistry. 3. The increase in arterial blood supply occurs later than the decrease in portal perfusion, which may indicate that the decrease in portal perfusion may not be the direct result of replacement by angiogenesis. 4. Some hepatocellular carcinomas with fatty metamorphosis, which are often hypovascular by angiographic evaluation, have hypervascular immunohistochemical characteristics.

Evaluation of effect of treatment for invasive bladder cancer by ultrasonography with intra-arterial infusion of carbon dioxide microbubbles

RATIONALE AND OBJECTIVES

The purpose of this study was to evaluate the diagnostic usefulness of the ultrasonography with intra-arterial infusion of carbon dioxide microbubbles (CO2) for invasive bladder cancer.

METHODS

Twelve patients with muscle-invading bladder cancer who were treated by concurrent radiotherapy and intra-arterial infusion of daily low dose of cisplatin using an implanted infusion port were included. A total of 30 studies was performed during the treatment to evaluate the visualization of the tumor and effect of the treatment compared with conventional ultrasonography, computed tomography, or cystoscopy.

RESULTS

Satisfactory visualization of the tumor in CO2 ultrasonography was obtained in all patients, in particular in those with flat tumor or prostatic invasion. The enhancement effect of CO2 on the tumor, which was maintained well in the late period of the treatment, made possible evaluation of the therapeutic effect. With respect to the evaluation of local response, disagreement between clinical response and the evaluation of CO2 ultrasonography was observed in two patients with definite differentiation between wall edema and residual tumor after treatment being difficult.

CONCLUSIONS

Carbon dioxide ultrasonography is easy to perform in patients treated with arterial infusion therapy using an implanted infusion port and provides practical information in evaluating therapeutic effect.

Significance of tumor vascularity as a predictor of long-term prognosis in patients with small hepatocellular carcinoma treated by percutaneous ethanol injection therapy

BACKGROUND/AIMS

We estimated the significance of the vascularity of small hepatocellular carcinoma (HCC) as a predictor of long-term prognosis in patients treated with percutaneous ethanol injection therapy (PEIT/PEI).

METHODS

Fifty-four patients who have been followed-up in our hospital and who had HCC less than 20 mm in diameter were observed for 199 to 2074 days. Hepatic angiography (digital subtraction angiography; DSA and ultrasound angiography with intraarterial CO2 microbubbles; USAG) was performed before treatment in all cases, and the vascularity of the tumor was clinically evaluated. The survival rate was analyzed according to this vascularity.

RESULTS

Of the 54 tumors, 24 had tumor stain on DSA, while 30 did not, and 38 showed enhancement on USAG, while 16 did not. The 3- and 5-year survival rates were 48.7 and 34.1% and 89.7 and 69.7% of patients with negative staining HCC (p = 0.0723). The rates were 48.6 and 36.7%, respectively, of patients with positive enhancement HCC on USAG, and both rates were 85.7% of patients with negative enhancement HCC (p = 0.0231).

CONCLUSIONS

Tumor vascularity will play a role in the long-term prognosis of these patients with small HCC when they are treated with PEIT/PEI.

Gray scale second harmonic imaging of the liver: a preliminary animal study

Gray scale second harmonic imaging (2.5 MHz/5.0 MHz) was evaluated in preliminary animal studies with a new ultrasound contrast agent (FS069). FS069 was administered intravenously in 10 rabbits (6 with normal liver, and 4 with implanted VX-2 tumors) and two woodchucks with hepatocellular carcinomas. The vasculature (including tumor vessels) and liver parenchyma were clearly enhanced at a low dosage (optimal dose was from 0.1 to 0.2 mL/kg) in all cases. Enhancement was reproducible and generally dose-dependent. Tumors were enhanced well during the early phase and tumor enhancement disappeared earlier than that of surrounding normal liver. Arterial phase and portal phase were easily distinguished and patterns of enhancement were diagnostic of the tumors. Gray scale second harmonic imaging is useful in the detection of hepatic tumors and in diagnosis of their hemodynamics.

Possibility of differentiating small hyperechoic liver tumours using contrast-enhanced colour Doppler ultrasonography: a preliminary study

We performed a preliminary study to investigate the possibility of differentiating small hyperechoic liver tumours, including hepatocellular carcinomas (HCCs), haemangiomas and focal fatty lesions, by administering a galactose-based contrast agent (SH/TA-508 (Levovist)) during colour Doppler ultrasonography (US). Ten patients (age range: 48-81 years) with small liver tumours (four HCCs, four hemangiomas and two focal fatty lesions) of less than 20 mm in diameter presented with hyperechoic masses with no intratumoural colour signals on conventional colour Doppler US. All patients subsequently underwent colour Doppler US with this contrast agent. Colour Doppler images of the tumours were assessed before and after the intravenous injection of 8 ml of the contrast agent at a concentration of 400 mg/ml. Prior to injection of the contrast agent, no intratumoural colour signals were observed in any cases. After injection, intratumoural colour signals appeared in all HCCs and in two haemangiomas with tumour-margin enhancement. The enhanced colour signals appeared to be related to cardiac contraction in the HCCs, but not in the haemangiomas. In the remaining two haemangiomas, only tumour-margin enhancement was observed. In the focal fatty lesions, neither intratumoural nor tumour-margin enhancement was observed. These results, although preliminary, suggest that the detection of colour Doppler signals is improved by using a contrast agent and the differences between enhanced colour signals from HCCs and haemangiomas may help differentiate hyperechoic HCCs from other hyperechoic tumours, including haemangiomas and focal fatty lesions.

Etiology, screening, and treatment of hepatocellular carcinoma

The prognosis with large hepatocellular carcinomas is poor, and only palliative treatment is available. Small tumors are amenable to several modes of treatment, including liver transplantation, resection, or alcohol injection, with acceptable 5-year survival rates. Although the value of screening for hepatocellular carcinoma has yet to be shown, these data, coupled with the recognition of at-risk groups and useful diagnostic techniques, might encourage the clinician to screen at-risk patients in the clinic. New imaging techniques such as ultrasonographic angiography enhanced with CO2 microbubbles, or color Doppler ultrasound, may clarify the intratumoral blood flow of small tumors.

Detection of hepatocellular carcinoma by intraarterially enhanced ultrasonography with CO2 microbubbles. Comparison with DSA, dynamic CT, and Lipiodol CT

PURPOSE

To evaluate the diagnostic value of contrast-enhanced US with CO2 microbubbles (EU) for HCCs. Detectability was compared with DSA, dynamic CT, and Lipiodol CT.

MATERIAL AND METHODS

Forty-seven histologically proven HCCs detected with US were evaluated with EU, DSA, and dynamic CT. In 23 patients (35 lesions), Lipiodol CT was also performed. The size of the tumors ranged from 8 to 71 mm (average 28.1 mm); 24 lesions were smaller than 20 mm and 23 lesions were larger than 20 mm.

RESULTS

Overall detection was possible in 40 of 47 lesions (85%) by EU, in 32 of 47 (68%) by DSA, in 33 of 47 (74%) by dynamic CT, and in 27 of 35 (77%) by Lipiodol CT. In tumors smaller than 20 mm, detection was possible in 21 of 24 lesions (88%) by EU, 14 of 24 (58%) by DSA, 14 of 24 (58%) by dynamic CT, and 11 of 17 (65%) by Lipiodol CT.

CONCLUSION

EU has significant diagnostic value for detection of HCCs, particularly tumors smaller than 20 mm.

Imaging: focus on hepatocellular carcinoma and liver transplantation

The choice of management for the patient with HCC hinges on precise localization and staging of the disease process. All the major imaging modalities are employed to achieve this end. US is frequently the initial means of detection of the lesion. Since percutaneous needling may lead to tumour dissemination, the temptation to proceed to imaging-guided biopsy should be resisted until a full evaluation has been completed and it is clear that neither curative surgery nor transplantation is a therapeutic option. CT scanning is considered to be superior to ultrasound both in detection and staging of the disease. A variety of modifications to the technique, including CT arterio-portography and lipiodol-CT, is used to obtain optimum results. The role of MRI has not yet been established but initial results suggest that this may be the optimum means of scanning the patient following percutaneous or intra-arterial therapy. Angiography is generally performed prior to resection and may be combined with the delivery of chemotherapeutic and embolic agents pre-operatively or as a definitive palliative procedure. Imaging-guided percutaneous alcohol is also a useful palliative measure where the lesion is small. In the majority of cases, resection is not feasible. In a selected few liver transplantation is an option. Imaging requirements of the potential liver transplant candidate depend on the nature of the underlying liver problem. A general assessment including a chest X-ray and US with Doppler imaging of the hepatic vascular structures is sufficient in the majority. In children with complex structural anomalies and in patients with bile duct disease or tumours, the full range of investigations is required. US, cholangiography CT and angiography may all be required in the diagnosis and management of post-transplant complications.

Serial hemodynamic measurements in well-differentiated hepatocellular carcinomas

We performed serial hemodynamics in 15 patients with 21 well-differentiated hepatocellular carcinomas. The total length of the observation period ranged from 129 to 678 days (median, 368). We investigated both arterial and portal blood flow at intervals of at least 4 months. Arterial blood flow was measured with carbon dioxide-enhanced ultrasonography (US), and portal blood flow was measured with computed tomographic arterial portography (CTAP). None of the tumors were hypervascular on the initial study; however, by the final study nine nodules (42.9%) had become homogeneously hypervascular, two (9.5%) had become partially hypervascular, and the others did not change. Of 10 nodules without portal blood supply on any study, 8 became hypervascular by the final study. Of 11 nodules with portal blood supply on the initial study, a follow-up study showed no change in portal flow in 6 and the loss of portal flow in 5. Four of these five became hypervascular, with a documented loss of portal flow before the increase in arterial flow. The doubling time of tumors with a homogeneous increase in arterial blood flow ranged from 89 to 333 days (median, 172), whereas the doubling time of other tumors ranged from 227 to 607 days (median, 392). Thus, growth rate and vascularity in well-differentiated hepatocellular carcinoma are closely correlated. When the well-differentiated hepatocellular carcinoma has portal blood flow and is not hypervascular, it grows slowly. On the other hand, when it loses portal blood flow and becomes hypervascular, it grows rapidly.

Ultrasound contrast agents: a review

During the past 25 years, many attempts have been made to establish effective ultrasound contrast agents for both cardiac and noncardiac applications. The ideal ultrasound contrast agent would be: (a) nontoxic; (b) injectable intravenously; (c) capable of passing through the pulmonary, cardiac and capillary circulations; and (d) stable for recirculation. A variety of potential ultrasound contrast agents have been or are now under development. Present and future ultrasound contrast agents should provide for increased diagnostic capabilities in a variety of normal and abnormal vessels and organs throughout the body. These agents will enhance tumor vascularity, delineate areas of ischemia, as well as improve visualization of vascular stenosis. Future developments with modification of ultrasound equipment should increase the capabilities of these agents to improve imaging as well as Doppler sensitivity.

Treatment of small hepatocellular carcinomas

There is growing interest in screening to detect symptomless hepatocellular carcinoma (HCC), which should be easier to treat than symptomatic tumours. Combined alpha-fetoprotein and ultrasound monitoring can detect HCCs of 1 cm, and Lipiodol retention can be detected in tumours smaller than 1 cm. A number of treatment options are available. Surgical resection may be curative in selected patients with a single small tumour, but the cirrhotic patient is left with a diseased liver and the risk of tumour recurrence or death from underlying liver dysfunction. Orthotopic liver transplantation is a rational treatment for patients with decompensating cirrhosis and a small HCC, but it is expensive and necessitates immunosuppression. A variety of targeted or local therapies, either individually or in combination, can be used to treat HCC. These include percutaneous alcohol injection into an HCC, which may be an alternative to surgical resection. Tumour necrosis can be seen after targeted Lipiodol chemotherapy or radiotherapy. Transcatheter arterial embolisation selectively embolises the feeding artery, and can be combined with Lipiodol chemotherapy. Small tumours are thus amenable to treatment, even in patients who cannot have surgery. Screening and treatment for symptomless HCC seems justified, unless controlled trials teach us differently.