Hepatocellular carcinoma: assessment of resectability by computed tomography and ultrasound

Site and Number of Liver Tumors Recorded at Angiography and Computed Tomography Compared with the Findings at Laparotomy and of Resected Liver Specimens

Angiography and computed tomography (CT) were performed in 96 patients before laparotomy for an intended liver resection. Of these, 73 patients underwent liver resection, from a local excision to a trisegmentectomy. The accuracy of angiography in tumor localization was 77 per cent when the results were compared with the findings at laparotomy and from resected specimens. With CT the accuracy was 85 per cent. In 47 patients an analysis of the number of tumor nodules was possible. There were 76 nodules, and ***42 (55%) were correctly identified by angiography and 58% (76%) by CT. Thirty-four tumor nodules were not seen at angiography, with the majority of these situated in the left liver lobe. At CT, 18 nodules were not observed, about equal numbers in right and left lobes. Five lesions thought to be present at angiography (9 at CT), could not be verified upon inspecting the resected specimens. Neither angiography nor CT seems to be reliable enough for an accurate prediction of resectability of liver tumors prior to laparotomy.

Resectability of Liver Tumours Evaluated by Computed Tomography

In a retrospective study of CT examinations of liver tumours in 37 patients intra- and extrahepatic tumour growth was estimated in order to see if resectability could be predicted. The findings were compared with the evaluation at laparatomy. Four out of 15 tumours, resectable according to CT, turned out to be unresectable and 9 out of 37 CT examinations did not reveal the total extent of tumour growth. A more reliable preoperative radiologic assessment may be obtained by improvement of current CT techniques, by computed tomographic angiography, intraoperative ultrasound or MR imaging.

Evaluation of Intrahepatic Tumour Extent and Prediction of Resection Size in Liver Tumours by Computed Tomography, Ultrasonography and Angiography

Preoperative radiologic examinations were reviewed in 110 patients planned for liver resection. Forty-five patients had a CT examination within a month before the operation; 22 of these also had ultrasonography (US) and 38 had angiography. In a numeric analysis of lesions, true positive findings were observed at CT and US in 69 per cent and 61 per cent, respectively. Angiography, mainly performed to show the vascular anatomy and patency of the portal vein and not to optimize tumour detection, showed 55 per cent of the lesions. Attempts were made to predict resection size with CT by estimating intrahepatic tumour extent. CT showed correct tumour extent in 73 per cent but was inaccurate in 12 of 45 examinations. In 5 of these, tumour growth across the main and sagittal fissures was misinterpreted, with both under- and overestimations. Improvements of current imaging methods are needed to make the radiologic assessment prior to liver surgery more reliable.

Computed Tomography of Adrenal Metastases in Hepatocellular Carcinoma

Four patients with adrenal metastases from hepatocellular carcinoma (HCC) diagnosed with computed tomography are described. In three, the metastases showed a central area of low density due to tumor necrosis, irregular contrast enhancement, and a well-defined margin. They measured 8 cm or more in diameter. In one, the adrenal metastasis was at first a relatively small homogeneously solid mass, but later, when it grew larger, a central low density developed. Since the adrenal gland is the second most common site of metastasis from HCC at autopsy, a combination of an adrenal tumor and a liver tumor should suggest this possibility.

Prognostic factors for portal venous invasion in patients with hepatocellular carcinoma

BACKGROUND

Factors involved in portal venous invasion (PVI) must be clarified to enable better determination of therapeutic strategies and outcomes in patients with hepatocellular carcinoma (HCC).

METHODS

Of 365 patients with HCC who consulted our department between January 1999 and January 2003, 53 with PVI at the initial consultation were excluded, and the other 312 without PVI were included in this study. Of these patients, we compared liver function, tumor markers, and initial treatment between 287 patients without PVI during follow-up (until December 2004) and 25 patients who developed PVI, and investigated prognostic factors.

RESULTS

Multivariate analysis using a COX regression model showed that a Lens culinaris A-reactive fraction of alpha-fetoprotein (AFP-L3) rate of 15% or more, a des-gamma-carboxy prothrombin (DCP) level of 100 mAU/ml or more, multiple tumors, and a platelet count of 130 000/mm(3) or more were correlated with PVI.

CONCLUSIONS

HCC frequently infiltrated the portal vein in patients with a high rate of AFP-L3, a high level of DCP, or multiple tumors. Furthermore, the incidence of PVI was significantly higher in patients with a platelet count of 130 000/mm(3) or more.

Characterization of portal vein thrombus with the use of contrast-enhanced sonography

OBJECTIVES

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.

METHODS

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.

RESULTS

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.

CONCLUSIONS

Contrast-enhanced sonography can be helpful in discriminating between benign and malignant portal vein thrombi.

Case report: A hepatocellular carcinoma metastasis in the distal pancreas

Hepatocellular carcinoma is a highly malignant neoplasm. Extrahepatic metastases are found in 64% of patients with hepatocellular carcinoma. The lungs, regional lymph nodes, kidney, bone marrow and adrenals are common sites of metastases. Pancreatic metastases are not common (<5%). A case report of a hepatocellular carcinoma with a metastasis in the distal pancreas is presented. A resection of the primary tumour and metastasis was carried out with the patient still alive 16 months after resection. This case illustrates that hepatic resection for hepatocellular carcinoma with a single local metastasis can be reasonably considered although a cure has not been established.

Early enhancement of tumor thrombus in the portal vein on two-phase helical CT

We report a case of hepatocellular carcinoma with a portal vein thrombus that showed early arterial enhancement of dual-phase helical CT, which permitted a specific diagnosis of tumor portal venous thrombus.

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.

Occult hepatocellular carcinoma in cirrhosis: value of ultrasound-guided biopsy of portal vein system thrombus

We report two cases of occult hepatocellular carcinoma associated with alcoholic cirrhosis, in which the diagnosis of malignancy was respectively established by ultrasound-guided biopsy of umbilical vein and portal vein branch thrombus. When measurement of serum alpha-foetoprotein, and liver ultrasonography and/or computed tomography failed to clearly demonstrate hepatocellular carcinoma, the presence of a thrombosis of the portal vein system is highly suggestive of malignancy, which may be easily confirmed by venous biopsy.

Influence of hepatitis B virus infection and age on mode of growth of hepatocellular carcinoma

According to the extent of hepatic involvement of the tumor and that of portal vein invasion at the time of initial diagnosis, patients with hepatocellular carcinoma (HCC) were grouped into three or four groups. Correlations among the extent of hepatic involvement, extent of portal vein invasion, and prevalence of hepatitis B surface antigen (HBsAg) and age distribution were examined. The extent of hepatic involvement of the tumor and that of portal vein invasion were significantly greater in patients with positive HBsAg compared with findings in the negative patients (P less than 0.001). For cases of both positive and negative HBsAg, patients with a more extensive HCC were significantly younger. Results of the multivariate logistic regression analysis showed that hepatitis B antigenemia and younger age were statistically significant and independent positive predictors of extensive HCC. These results strongly suggest that hepatitis B surface antigenemia and age play an important role in the growth mode and the kinetics of HCC in Japanese patients.

Sonographic diagnosis of portal vein invasion in patients with hepatocellular carcinoma: comparison with arterial portography

The results of sonographic assessment of the main portal vein were compared with arterial portography in 65 patients with documented hepatocellular carcinoma. When compared with fully-diagnostic angiograms, obtained in 54 patients, sensitivity of ultrasound was 64% with a specificity of 98%. We conclude that ultrasound is a valuable first-line method of detecting portal vein invasion in the preoperative assessment of patients with hepatocellular carcinoma.

Small hepatocellular carcinoma: detection with sonography, computed tomography (CT), angiography and Lipiodol-CT

Seventy-three small hepatocellular carcinomas under 5 cm in diameter in 47 patients were examined by sonography, computed tomography (CT), hepatic angiography and CT after intra-arterial injection of iodized poppy-seed oil (Lipiodol-CT). The imaging techniques that first led to detection of small hepatocellular carcinomas were sonography in 53 cases (72.6%), CT in 10 (13.7%), angiography in eight (11%) and Lipiodol-CT in two (2.7%). Sensitivity for detecting small hepatocellular carcinomas was 73% with sonography, 82% with CT, 86% with angiography and 96% with Lipiodol-CT. As a screening method, sonographic and CT results in detecting small hepatocellular carcinomas were not significantly different (p greater than 0.05). Lipiodol-CT was superior to sonography (p less than 0.01), CT (p less than 0.01) and angiography (p less than 0.05) in detecting small hepatocellular carcinomas. We believe that the combined use of Lipiodol-CT with screening methods such as sonography or CT is indispensable for the accurate detection of small hepatocellular carcinomas.

Malignant liver tumors

In this monograph we have presented the most important liver tumors in children and adults with pathological correlation. We believe that this information may be useful for understanding the varying radiological findings in malignant liver tumors since it includes pathological findings responsible for the radiographic images. It is clear that there are no characteristic signs that could establish a specific radiological diagnosis in malignant liver tumors. However, careful analysis of the radiographic images provided by different modalities and correlations with the clinical data may, in many cases, suggest a correct preoperative diagnosis.

Hepatic venography in the surgical assessment of hepatic tumours

Hepatic venography was performed on 80 patients with hepatic tumours for the pre-operative assessment of resectability. Sixty-six patients subsequently underwent laparotomy, 27 undergoing hepatic resection. Forty-two patients had metastases from colo-rectal primaries, 19 hepatocellular carcinoma and 19 a variety of other tumours. The type and frequency of the abnormalities shown on venography were noted for each tumour category and for their hepatic segmental distribution. The results of venography were compared with those of arteriography, computed tomography and ultrasound and with the findings at laparotomy. Displacement was the commonest abnormality seen while encasement or obstruction occurred less frequently and tumour invasion was rare. The sensitivity of venography in correctly identifying the segmental distribution of tumour deposits was 41%. Sensitivity was poorest with tumours in the left lobe (31%) and bilobar tumours (0%). Venography was most sensitive in detecting tumour involvement of the major segmental hepatic veins and inferior vena cava (100%). Peripheral colo-rectal metastases frequently produced no venographic abnormality. Hepatic venography provides no additional information to arteriography, computed tomography or ultrasound in patients with peripheral or bilobar tumour deposits. Some additional information may be obtained with central tumours and venography is the most accurate means of detecting tumour involvement of the major segmental hepatic veins.

Ultrasonography in oncology. A review

The applications of ultrasonography (US) in oncology have rapidly increased during the past few years. Technical improvements, development of new technologies, easy availability, and non-invasiveness are some of the reasons for the rapid diffusion of US. Nowadays a large number of malignancies, both superficial and deep-seated, can be examined by US. In order to give an overview of the present role of US in oncology it is necessary to discuss many different topics including tissue characterization, diagnostic role, staging, follow-up and future developments.

Hepatic vein involvement in hepatocellular carcinoma

A retrospective review of the dynamic computed tomography (CT) and ultrasound scans from examinations of 134 patients with hepatocellular carcinoma was undertaken with emphasis on evaluation of hepatic vein involvement. Hepatic veins were involved in 8 patients (5.9%). Portal vein obstruction was associated in 7 of these cases. Sonography demonstrated hepatic vein involvement in 6 cases was considered within normal limits in 1 and failed to display hepatic veins in another. Dynamic CT was superior in depicting venous obstruction in all the cases by different signs including (a) hypodensity and enlargement of the vessel, (b) perivenous arterial hypervascularization surrounding the hypodense intraluminal region, and (c) hemokinetic changes in relation to the outflow obstruction. The frequency and significance of these CT signs are discussed and correlated in 2 patients with magnetic resonance imaging (MRI) data.

Tumor thrombosis of the inferior vena cava due to retroperitoneal germ cell tumor

Three patients (2 males and 1 female), aged 17-28 years, with tumor thrombosis of the inferior vena cava due to retroperitoneal germ cell tumor are reported. Diagnostic and therapeutic implications of this condition are discussed.

Ultrasound of primary hepatic tumours in childhood

Ultrasound scans of 18 children with primary hepatic tumours were reviewed to assess the accuracy of ultrasound in determining hepatic origin, extent, resectability, and histology. Using basic landmarks, ultrasound correctly predicted extent and resectability in 72% of patients. Accuracy would be increased by more detailed scanning to determine segmental and lobar landmarks. Hepatoblastoma demonstrated a characteristic appearance of a well-defined hyperechoic mass. Other tumour types showed some overlap in ultrasound appearances. Ultrasound examination overestimated the incidence of obliteration of the IVC lumen, and such patients require inferior venacavography to assess the true status of the cava preoperatively.

Malignant tumors of the liver

HCC occurs infrequently in Western countries, with recent increases being reported in California and parts of Europe. Southeast Asia, Japan, and South Africa continue to have a high incidence of this tumor with HBV, cirrhosis, and the ingestion of aflatoxins being identified as probable risk factors. Although the majority of patients present with abdominal pain or mass indicative of extensive tumor, asymptomatic, small HCCs are being detected with increasing frequency. Early detection in high-risk individuals is best accomplished by screening with serum AFP determinations and liver ultrasonography. CT and arteriography are valuable preoperatively in defining anatomy and determining resectability. Five-year survival following resection for cure of HCC ranges from 20 to 40 per cent, with improved survival reported for small asymptomatic tumors. Resection of metastatic liver tumors from colorectal primaries results in 48 per cent 2-year and 24 per cent 5-year survivals, with an additional 5 per cent dying of recurrent cancer after 5 years. Although patients with simultaneous and metachronous metastases do equally well after resection, the presence of four or more individual deposits adversely affects survival. Hepatic artery ligation or embolization can produce a significant palliative reduction in total tumor mass in patients with unresectable liver metastases. Regional chemotherapy using implantable hepatic artery drug infusion pumps is promising, with reports of prolonged survival compared with historical controls. Regional hyperthermia, laser vaporization of tumor, and cryosurgical techniques may prove to have useful roles in the selective treatment of liver cancer in the future. Orthotopic liver transplantation has been successful primarily in those in whom the malignancy is found incidentally in the chronically diseased liver.

Computed tomography and ultrasonography of hepatoma

Computed tomography (CT) scans and sonograms of 37 patients with hepatocellular carcinoma (hepatoma) were reviewed to determine the characteristics of the tumour and to compare the modalities in terms of accuracy in defining tumour morphology and ability to predict vascular invasion and extrahepatic spread. By CT, slightly over 50% of the tumours were multicentric, about 40% were solitary, and the rest were diffuse. About half of the hepatomas were heterogeneous in density before injection of contrast agent and most became enhanced in a non-uniform manner. In addition, about a quarter of the tumours either became visible or were better seen after injection of contrast agent. At sonography, approximately two-thirds of the neoplasms were thought to be solitary and one-third multicentric. The majority also had a mixed echo texture. Although the lesion was identified in all 13 patients who had both studies, sonography underestimated the extent of hepatic involvement in 38% of the cases. Sonography also failed to demonstrate lymphadenopathy that was detected by CT in two patients. In general, both techniques were effective in identifying vascular invasion. CT was very accurate in showing the extent of hepatic involvement but was unable to identify direct invasion of neighbouring structures. Because each technique has limitations in the evaluation of hepatoma, we believe that both should be performed if curative resection is being considered.

Computed tomographic angiography of the liver via the coeliac axis

Sixty computed tomographic angiographic (CTA) examinations of the liver were performed with contrast injection into the coeliac axis. Data from both an arterial and a portal venous phase were recorded. In 41 patients it was possible to compare the results of CTA with palpation of the liver during laparotomy. The results from CTA and laparotomy were the same in 35 patients (85%). In one patient CTA disclosed verified liver lesions not diagnosed at laparotomy. There were 2 false negative and 3 false positive CTA examinations. In the remaining 19 patients, a clinical follow-up period of at least 6 months was used to evaluate the results of CTA. In the 7 patients in whom CTA showed benign lesions or a normal liver parenchyma, the clinical follow-up revealed no evidence of tumour growth in the liver.

Radionuclide angiography and scintigraphy in hepatocellular carcinoma

Among 1 257 patients subjected to liver-spleen (RES) scintigraphy and radionuclide angiography (RNA), there were 13 cases of histologically confirmed hepatocellular carcinoma (1%). All 13 patients had scintigraphic findings indicating cirrhosis. Histologically, cirrhosis was present in only 9 out of 11 cases in which liver parenchyma was available for examination. One patient had hemochromatosis without evidence of cirrhosis. In 11 cases, the tumor was clearly demonstrated as a defect in the static scintigram. However, in 2 cases with cirrhosis and poorly differentiated hepatocellular carcinoma, the tumor nodules were hardly discernible. In RNA, the tumor displayed high activity in the arterial phase and decreasing activity during the portal phase, ending up as a defect. At RNA, the lesion was clearly outlined in 12 cases, including the 2 patients in whom the scintigraphic findings were inconclusive; in one case with severe cirrhosis and a well differentiated hepatocellular carcinoma, the tumor was barely detectable. We conclude that a combination of RNA and scintigraphy is a valuable screening which usually provides a correct diagnosis in hepatocellular carcinoma.