Hepatocellular carcinoma. A clinical and pathologic analysis of 57 hepatectomy cases

Deep Learning Classification and Quantification of Pejorative and Nonpejorative Architectures in Resected Hepatocellular Carcinoma from Digital Histopathologic Images

Liver resection is one of the best treatments for small hepatocellular carcinoma (HCC), but post-resection recurrence is frequent. Biotherapies have emerged as an efficient adjuvant treatment, making the identification of patients at high risk of recurrence critical. Microvascular invasion (mVI), poor differentiation, pejorative macrotrabecular architectures, and vessels encapsulating tumor clusters architectures are the most accurate histologic predictors of recurrence, but their evaluation is time-consuming and imperfect. Herein, a supervised deep learning-based approach with ResNet34 on 680 whole slide images (WSIs) from 107 liver resection specimens was used to build an algorithm for the identification and quantification of these pejorative architectures. This model achieved an accuracy of 0.864 at patch level and 0.823 at WSI level. To assess its robustness, it was validated on an external cohort of 29 HCCs from another hospital, with an accuracy of 0.787 at WSI level, affirming its generalization capabilities. Moreover, the largest connected areas of the pejorative architectures extracted from the model were positively correlated to the presence of mVI and the number of tumor emboli. These results suggest that the identification of pejorative architectures could be an efficient surrogate of mVI and have a strong predictive value for the risk of recurrence. This study is the first step in the construction of a composite predictive algorithm for early post-resection recurrence of HCC, including artificial intelligence-based features.

Advances in Histological and Molecular Classification of Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is a primary liver cancer characterized by hepatocellular differentiation. HCC is molecularly heterogeneous with a wide spectrum of histopathology. The prognosis of patients with HCC is generally poor, especially in those with advanced stages. HCC remains a diagnostic challenge for pathologists because of its morphological and phenotypic diversity. However, recent advances have enhanced our understanding of the molecular genetics and histological subtypes of HCC. Accurate diagnosis of HCC is important for patient management and prognosis. This review provides an update on HCC pathology, focusing on molecular genetics, histological subtypes, and diagnostic approaches.

Macrotrabecular-Massive Hepatocellular Carcinoma: Light and Shadow in Current Knowledge

The subject of this narrative review is macrotrabecular-massive hepatocellular carcinoma (MTM‐HCC). Despite their rarity, these tumours are of general interest because of their epidemiological and clinical features and for representing a distinct model of the interaction between the angiogenetic system and neoplastic cells. The MTM‐HCC subtype is associated with various adverse biological and pathological parameters (the Alfa-foetoprotein (AFP) serum level, tumour size, vascular invasion, and satellite nodules) and is a key determinant of patient prognosis, with a strong and independent predictive value for early and overall tumour recurrence. Gene expression profiling has demonstrated that angiogenesis activation is a hallmark feature of MTM-HCC, with overexpression of both angiopoietin 2 (ANGPT2) and vascular endothelial growth factor A (VEGFA).

Can primary hepatocellular carcinoma histomorphology predict extrahepatic metastasis?

Studies comparing the histomorphologic features and phenotypic heterogeneity between primary and its corresponding metastatic hepatocellular carcinoma (HCC) are lacking. The aim of this study was to assess and compare the histomorphologic features and heterogeneity between primary and metastatic HCC. A total of 39 cases with both primary and metastatic tissues were identified from pathology archives (2000-2019). The common sites of metastasis included lung (28.21%), abdominal cavity (25.64%), lymph nodes (20.51%), bone (17.95%), soft tissue (15.38%), and adrenal gland (10.26%). Both the primary and metastatic tumors showed heterogeneity in intratumoral histologic patterns (87.18% and 76.92%, respectively). The most common histologic pattern was solid in both primary (61.54%) and metastases (56.41%), followed by macrotrabecular in primary (17.95%) and metastases (10.26%). Among HCC-subtypes, macrotrabecular-massive HCC was the most common subtype in both primary and metastases (28.21% each). Primary tumors in noncirrhotic livers were more likely to have larger size and microvascular invasion than those in cirrhotic livers. The histomorphology (histologic pattern, subtype, and grade) between the primary and metastases was discordant in about 50% cases (48.72%, 48.72%, and 51.28%, respectively). Our findings exhibit significant intratumoral heterogeneity and histomorphologic discordance between primary and metastatic HCCs. The solid and macrotrabecular histologic patterns and the macrotrabecular-massive subtype were the most common histomorphologic features seen in primary tumors associated with metastasis. Further studies to identify and explore different pathways that promote HCC metastasis and to compare the differences between primary and metastatic tumors on a larger cohort are needed to better understand the pathogenesis of metastasis.

Gadoxetic acid-enhanced MRI of macrotrabecular-massive hepatocellular carcinoma and its prognostic implications

BACKGROUND & AIMS

Despite the clinical and genetic significance of macrotrabecular-massive hepatocellular carcinoma (MTM-HCC), its characteristics on imaging have not been described. This study aimed to characterise MTM-HCC on gadoxetic acid-enhanced MRI and to evaluate the diagnostic accuracy and prognostic value of these imaging characteristics.

METHODS

We enrolled 3 independent cohorts from 2 tertiary care centres. The 3 cohorts consisted of a total of 476 patients who underwent gadoxetic acid-enhanced MRI and surgical resection for treatment-naïve single HCCs. Independent review of histopathology and MRI by 2 reviewers was performed for each cohort, and inter-reader agreement was evaluated. Based on the result of MRI review in the training cohort (cohort 1), we developed 2 diagnostic criteria for MTM-HCC and evaluated their prognostic significance. The diagnostic performance and prognostic significance were validated in 2 validation cohorts (cohorts 2 and 3).

RESULTS

We developed 2 diagnostic MRI criteria (MRIC) for MTM-HCC: MRIC-1, ≥20% arterial phase hypovascular component; MRIC-2, ≥50% hypovascular component and 2 or more ancillary findings (intratumoural artery, arterial phase peritumoural enhancement, and non-smooth tumour margin). MRIC-1 showed high sensitivity and negative predictive value (88% and 95% in the training cohort, and 88% and 97% in the pooled validation cohorts, respectively), whereas MRIC-2 demonstrated moderate sensitivity and high specificity (47% and 94% in the training cohort, and 46% and 96% in the pooled validation cohorts, respectively). MRIC-2 was an independent poor prognostic factor for overall survival in both training and pooled validation cohorts.

CONCLUSIONS

Using gadoxetic acid-enhanced MRI findings, including an arterial phase hypovascular component, we could stratify the probability of MTM-HCC and non-invasively obtain prognostic information.

LAY SUMMARY

Macrotrabecular-massive hepatocellular carcinoma (MTM-HCC) is a histopathologic subtype of HCC characterised by aggressive biological behaviour and poor prognosis. We developed imaging criteria based on liver MRI that could be used for the non-invasive diagnosis of MTM-HCC. HCCs showing imaging findings of MTM-HCC were associated with poor outcomes after hepatic resection.

Hepatocellular carcinoma: making sense of morphological heterogeneity, growth patterns, and subtypes

Hepatocellular carcinomas are not a homogenous group of tumors but have multiple layers of heterogeneity. This heterogeneity has been studied for many years with the goal to individualize care for patients and has led to the identification of numerous hepatocellular carcinoma subtypes, defined by morphology and or molecular methods. This article reviews both gross and histological levels of heterogeneity within hepatocellular carcinoma, with a focus on histological findings, reviewing how different levels of histological heterogeneity are used as building blocks to construct morphological hepatocellular carcinoma subtypes. The current best practice for defining a morphological subtype is outlined. Then, the definition for thirteen distinct hepatocellular carcinoma subtypes is reviewed. For each of these subtypes, unresolved issues regarding their definitions are highlighted, including recommendations for these problematic areas. Finally, three methods for improving the research on hepatocellular carcinoma subtypes are proposed: (1) Use a systemic, rigorous approach for defining hepatocellular carcinoma subtypes (four-point model); (2) Once definitions for a subtype are established, it should be followed in research studies, as this common denominator enhances the ability to compare results between studies; and (3) Studies of subtypes will be more effective when morphological and molecular results are used in synergistic and iterative study designs where the results of one approach are used to refine and sharpen the results of the other. These and related efforts to better understand heterogeneity within hepatocellular carcinoma are the most promising avenue for improving patient care by individualizing patient care.

Fibronodular hepatocellular carcinoma-a new variant of liver cancer: clinical, pathological and radiological correlation

AIMS

To establish and define a new, not previously reported hepatocellular carcinoma (HCC) variant, termed fibronodular HCC (FN-HCC).

METHODS

We retrospectively reviewed 290 HCC cases and identified 29 FN-HCC and 24 scirrhous HCC (SCHCC). Clinical, pathological and radiological features of FN-HCC were reviewed and compared with 30 conventional HCCs (CV-HCC) and SC-HCC.

RESULTS

FN-HCCs were more likely to arise in non-advanced fibrotic livers with lower advanced Barcelona Clinic Liver Cancer (BCLC) stage, had lower rates of progression and longer time to progression and were more likely to be surgically resected compared with CV-HCCs and SC-HCCs. Imaging analysis of FN-HCCs demonstrated higher rates of non-peripheral washout and a new distinct pattern of enhancement which is characterised by the presence of multiple rounded nodules within a lesion embedded in fibrotic-appearing parenchyma.

CONCLUSIONS

FN-HCC may represent a specific variant of HCC with distinct pathological, radiological and clinical features with potential ramifications for outcome.

Hepatocellular carcinoma: Liver biopsy in the balance

The use of liver biopsy to diagnose hepatocellular carcinoma is governed by the balance of the risks of the procedure (morbidity, mortality, inadequate sampling), the relative utility of non-invasive techniques and the benefits of precise diagnosis, prognostic and theragnostic information and access to tissue for molecular analysis. In this issue of Hepatology, identification of the macrotrabecular subtype of hepatocellular carcinoma on liver biopsy is shown to add clinically useful prognostic information as well as molecular correlations.

A Clinico-Pathologic Study of Clear-Cell Hepatocellular Carcinoma

We reviewed the pathologic and clinical features of 7 cases of clear-cell hepatocellular carcinomas. Tumor cells had a typical clear, empty cytoplasm due to prominent accumulation of glycogen and lipid droplets, as demonstrated by ultrastructural study in one of our cases. Follow-up of the 7 patients did not confirm the better prognosis of this tumor reported by other investigators. The clinical course of our cases was more unfavorable than that of the other 130 cases of usual hepatocellular carcinomas treated at this Institute.

Histologic Grade and Mitotic Index as Predictors of Microvascular Invasion in Hepatocellular Carcinoma

OBJECTIVES

Microvascular invasion is a well-known risk factor for hepatocellular carcinoma recurrence and mortality after hepatic resection and liver transplant. We sought to determine the clinico-pathological predictive factors associated with microvascular invasion.

MATERIALS AND METHODS

We studied all patients who had undergone liver transplant because of hepatocellular carcinoma between July 2001 and December 2010 at our institution. Laboratory tests, clinical, and demographic data were obtained. Histopathological hematoxylin and eosin specimens were performed by a single liver pathologist.

RESULTS

During the study, 107 patients had LT because of HCC and they were selected for this investigation: 76 were men (71%) and 31 women (29%) (mean age, 56.8 ± 8.7 y). It was not possible to retrieve histologic samples from 5 patients; therefore, the final studied analysis was 102 individuals. Tumor recurrence rate was 12.9%. One-, three- and five-year overall survivals were 75.0%, 71.4%, and 67.5%. Mitotic index, histologic grade, tumor architecture, alpha-fetoprotein, and tumor fibrosis were associated with microvascular invasion on univariate analysis. Significant independent predictors of microvascular invasion on logistic regression analysis were histologic grade and mitotic index (P < .001; odds ratio, 3.16; 95% confidence interval, 1.525-4.156, and P = .046; odds ratio, 2.56; 95% confidence interval, 1.061-6.451).

CONCLUSIONS

Mitotic index and histologic grade are significant predictors of microvascular invasion. No other risk factor was identified in the logistic regression. As both pathological characteristics may be assessed by liver biopsy, these results highlight the importance of discussing pretransplant liver biopsy to access prognosis and define treatment modalities in the setting of liver transplant.

Impact of hepatectomy for huge solitary hepatocellular carcinoma

BACKGROUND

To evaluate the surgical outcome of patients with huge solitary hepatocellular carcinoma (HCC, ≥10 cm in diameter) without major vascular invasion.

METHODS

We retrospectively studied 177 patients with huge HCC (≥10 cm in diameter) who underwent hepatectomy from 1990 to 2008. Surgical outcomes and clinicopathological characteristics were compared among 54 patients with solitary HCC without a major portal vein tumor thrombus (MPVT), 53 patients with multiple HCCs without MPVT, and 70 patients who have HCC with MPVT.

RESULTS

The mean tumor size and indocyanine green retention rate at 15 min showed no significant difference among patients groups. The overall 5-year survival rate was significantly higher in patients with solitary HCC (79%) than in patients with multiple HCCs (31%, P < 0.0001) and MPVT (17%, P < 0.0001). In patients who underwent curative surgery, the 5-year disease-free survival rate was significantly higher in patients with solitary HCC (48%) than in patients with multiple HCCs (12%, P = 0.0008) and MPVT (12%, P = 0.0003). Multivariate analysis showed solitary HCC to be a significant independent prognostic factor for overall survival and disease-free survival.

CONCLUSIONS

Patients with solitary HCC without MPVT show a favorable surgical outcome even for tumor size ≥10 cm in diameter.

Seeding from hepatocellular carcinoma after percutaneous ablation: color Doppler ultrasound findings

BACKGROUND

We describe the clinical and color Doppler ultrasound findings in a series of cases of seeding from hepatocellular carcinoma (HCC) observed in patients treated with percutaneous ablation therapy (PAT) over a 15-year period.

METHODS

We reviewed the clinical and imaging records of 12 patients with cirrhosis (nine men and three women, age range 51-82 years, mean age 63 years) that showed neoplastic seeding from HCC occurring after one or more PAT procedures. Five of 12 cases of seeding were observed as a complication of 1080 PAT procedures (0.46%) performed in 545 patients (0.96%) by two of the authors (L.T., G.F.) over a long period (15 years) at different institutions. The other seven patients had been treated with PAT procedures at other institutions and had come to our attention during post-treatment follow-up.

RESULTS

The 12 patients who had seeding nodules had undergone the following PAT procedures: multisession conventional percutaneous ethanol injection (PEI) without anesthesia (four patients), single-session PEI with general anesthesia (three patients), single-session PEI with general anesthesia plus multisession conventional PEI (four patients), and single-session PEI plus radiofrequency ablation (one patient). Seeding nodules ranged from 0.9 to 6.0 cm (mean 1.7 cm). Eleven of 12 seeding nodules appeared as hypervascular hypoechoic nodules with smooth and regular margins and multiple intralesional vascular signals.

CONCLUSIONS

Clinical and imaging findings of seeding from HCC should be recognized by physicians who perform follow-up ultrasound examinations of patients who are treated with PAT. Early diagnosis of seeding can be reliably made by scanning the abdominal wall with small probes in the area where the previous PAT has been performed. Hypoechoic hypervascular pattern of the seeding nodule allows definitive diagnosis.

Tumor size predicts vascular invasion and histologic grade: Implications for selection of surgical treatment for hepatocellular carcinoma

Vascular invasion and high histologic grade predict poor outcome after surgical resection or liver transplantation for hepatocellular carcinoma (HCC). Despite the known association between tumor size and vascular invasion, a proportion of patients with large tumors can be treated surgically with excellent outcomes. Clarification of the association between tumor size, histologic grade, and vascular invasion has implications for patient selection for resection and transplantation. The objective of this study was to examine the relationship between HCC tumor size and microscopic (occult) vascular invasion and histologic grade in a multicenter international database of 1,073 patients who underwent resection of HCC. The incidence of microscopic vascular invasion increased with tumor size (< or =3 cm, 25%; 3.1-5 cm, 40%; 5.1-6.5 cm, 55%; >6.5 cm, 63%) (P < 0.005). Both size and number of tumors were important factors predicting vascular invasion. Among all patients with tumors 5.1 to 6.5 cm, microscopic vascular invasion was present in 55% compared with 31% for all patients with tumors 5 cm or smaller (P < 0.001). Among patients with solitary tumors only, microscopic vascular invasion was significantly more common in tumors measuring 5.1 to 6.5 cm (41%) compared with 27% of tumors 5 cm or smaller (P < 0.003). Tumor size also predicted histologic grade: 36% of tumors 5 cm or smaller were high grade, compared with 54% of lesions 5.1 to 6.5 cm (P = 0.01). High histologic grade, an alpha-fetoprotein level of at least 1000 ng/mL, and multiple tumor nodules each predicted occult vascular invasion in tumors larger than 5 cm. The high incidence of occult vascular invasion and advanced histologic grade in HCC tumors larger than 5 cm, as well as biologic predictors of poor prognosis, should be considered before criteria for transplantation are expanded to include these patients.

Liver transplantation for the treatment of moderately or well-differentiated hepatocellular carcinoma

OBJECTIVE

To determine the long-term results of liver transplantation for well- or moderately differentiated hepatocellular carcinoma (HCC).

SUMMARY BACKGROUND DATA

HCC patient selection for liver transplantation remains controversial, and deciding exclusively on the strength of criteria such as number and size of nodules appears prognostically inaccurate.

METHODS

Since 1991, preoperative tumor grading has been used at our center to establish whether a patient with HCC is fit for transplantation. Poorly differentiated HCC cases were excluded, while size and number of nodules were not considered as absolute selection criteria. Thirty-three patients with moderately or well-differentiated HCC were prospectively studied after liver transplantation. A group of 15 patients with incidental HCC transplanted during the same period were also evaluated and compared with the 33 patients with preoperatively diagnosed HCC.

RESULTS

On histologic examination, 38% of the entire group of 48 patients did not meet the "Milan criteria" and 42% were pTNM stages III and IV. The median follow-up was 44 months. The 5-year actuarial survival rate was 75% and recurrence-free survival was 92%. HCC recurred in only 3 patients (6%). The only histomorphologic variable differing significantly between incidental and nonincidental HCC was nodule size. The timing of diagnosis (incidental vs. nonincidental HCC), the Milan criteria, and the TNM stage revealed no statistically significant impact on overall and recurrence-free survival rates.

CONCLUSIONS

The routine pre-orthotopic liver transplantation tumor grading may represent a valid tool in the selection of unresectable HCC patients for transplantation.

Pathologic spectrum and prognostic significance of underlying liver disease in hepatocellular carcinoma

Although controversy persists about the influence of cirrhosis on the incidence of portal vein invasion and other prognostic indicators of recurrence and survival (e.g., histologic grade, mitotic activity, multiplicity), it is clear that the degree of cirrhosis is important for the long-term survival of patients with HCC. Multicentricity is especially important because it reflects the field carcinogenesis associated with viral hepatitis and particularly chronic HCV infection [59]. A better understanding of the different mechanisms linked to tumor recurrence will help select the best candidates for curative surgery and help tailor adjuvant therapy, such as interferon therapy, to each patient [60]. Finally, the importance of vascular invasion, number of tumors, and tumor size of HCCs in addition to the effect of fibrosis has led Vauthey et al [20] to propose a simplified staging of HCC with better prognostication of survival.

A mechanical model of tumor encapsulation and transcapsular spread

In this paper, a mathematical modeling framework is presented which describes the growth, encapsulation, and transcapsular spread of solid tumors. The model is based on the physical forces and cellular interactions involved in tumorigenesis and is used to test and compare the active (foreign body hypothesis) and passive (expansive growth hypothesis) hypotheses of capsule formation, such investigations being ideally suited to our mechanical model. The model simulations lead us to predict that, although an active response can successfully control tumor growth via the deposition of large amounts of collagen, this alone is insufficient for capsule formation. In contrast, a solely passive responsive is capable of producing an encapsulated tumor with minimal accumulation of connective tissue within the tumor. When both responses are active, a denser capsule forms and there is a significant increase in connective tissue within the tumor. Using a modified version of the model, in which tumor cells are assumed to produce degradative proteases at a rate which depends on the pressure they experience, it is also possible to show that transcapsular spread or invasion of the tumor may be due to the production by the tumor cells of proteases and their subsequent action.

Histological, genomic and clinical heterogeneity of clear cell hepatocellular carcinoma

AIMS

The aim of the study was to determine whether clear cell type hepatocellular carcinoma should still be regarded as a separate uniform diagnostic entity.

METHODS AND RESULTS

We retrospectively studied 118 cirrhotic patients with hepatocellular carcinoma treated by orthotopic liver transplantation, and 31 noncirrhotic patients with hepatocellular carcinoma treated by either liver surgical resection or transplantation. The pathology of all liver resections was reviewed. Microsatellite instability was performed on paraffin-embedded samples at loci located on chromosomes 2p, 3p, 5q, 8q, 9p, 13q, 16q and 17p. Among the 118 cirrhotic patients, 10 (8.5%) had a clear cell hepatocellular carcinoma; these had clinical characteristics and prognosis similar to the other cirrhotic patients. No genetic alterations were detected in these tumours. Among the 31 noncirrhotic patients, one (3.2%) had a clear cell hepatocellular tumour. This 170-mm tumour had a lipid density on computed tomography, and its histology resembled chromophobe cell renal carcinoma. Furthermore, this tumour had unusual genomic alterations, with microsatellite instability in 6/8 chromosome loci.

CONCLUSIONS

Clear cell hepatocellular carcinoma is a heterogeneous entity in which a chromophobe cell subtype should be identified.

Hepatocellular carcinoma with spontaneous regression of multiple lung metastases

Spontaneously regressed lung metastasis of hepatocellular carcinoma (HCC) in a 82-year-old Japanese man with liver cirrhosis was recorded. Multiple nodular lesions of both lungs, up to 1 cm across, were shown on chest X-ray when the clinical diagnosis of HCC was made because of the presence of a liver mass on abdominal computed tomography (CT) scan and high serum alpha-fetoprotein (AFP) value. The lung lesions which were regarded clinically as metastasis of HCC decreased in number and size 7 months later, and subsequently disappeared a further 7 months radiographically. However, the liver mass revealed no reduction on abdominal CT, despite normalization of the serum AFP value, and the patient died 7 months after the disappearance of the lung lesions. The patient refused biopsy for the liver mass and anticancerous treatment during the course of the disease. At autopsy, the liver mass, 13 cm in diameter, histologically featured moderately differentiated HCC. Only one metastasis, 0.5 cm across, was obvious in the left lower lung lobe. In addition, there were 14 minute lesions in both lungs, up to 0.2 cm across, including three with complete necrosis and 11 with histocytic reaction and fibrosis. The necrotic tissue was filled with large ghostly cells that appeared to be debris from a neoplastic tissue, regardless of no viable tumor cells among them. The clinical and autopsy findings highly suggested that the patient developed spontaneous regression of multiple lung metastases of HCC and subsequently left the very small lesions as the vestige. Thus, the histology of these lesions may exhibit a process of the regression as the sequence of events, i.e., a transition from necrosis of the metastatic HCC to its fibrosis. Presence of an effective factor(s) in relation to the regression was unclarified. There has been no reported cases with regression of the only metastasis of HCC in the literature to date.

Complete remission of multiple hepatocellular carcinomas associated with hepatitis C virus-related, decompensated liver cirrhosis by oral administration of enteric-coated tegafur/uracil

We report a case of complete remission of multiple hepatocellular carcinomas after oral administration of enteric-coated tegafur/uracil. A 77-yr-old woman was diagnosed as having recurrent hepatocellular carcinoma associated with decompensated liver cirrhosis. We administered enteric-coated tegafur/uracil to this patient. After 1 month of oral administration, there was a decrease in tumor markers. An image analysis showed disappearance of hepatocellular carcinoma. No recurrence of the hepatocellular carcinoma was recognized for 18 months up to the time of the patient's death, which was due to massive bleeding from a hemorrhagic rectal ulcer. At autopsy, the tumor lesion had necrotized. Oral administration of enteric-coated granules containing tegafur/uracil may provide an effective treatment for hepatocellular carcinoma.

Evidence that "myofibroblast-like" cells are the cellular source of capsular collagen in hepatocellular carcinoma

BACKGROUND/AIMS

The prognosis for patients with hepatocellular carcinoma is poor although tumour encapsulation has been associated with improved survival and disease-free rates. While the source of the tumour capsule is unclear, the major role that activated hepatic stellate cells play in the deposition of liver matrix in normal and diseased states suggests the possible involvement of these cells in tumour encapsulation.

METHODS

Twenty-four liver tumours (seven encapsulated HCC, seven non-encapsulated HCC, 10 colorectal metastases) were studied. Activated hepatic stellate cells were identified by immunohistochemistry for alpha-smooth muscle actin (alpha-SMA) and in situ hybridization for pro-collagen alpha1 (I) mRNA. Collagen deposition was localized using Masson's trichrome stain.

RESULTS

Pro-collagen alpha1 (I) mRNA co-localized to alpha-SMA positive hepatic stellate cells within the region of increased collagen deposition in (i) the tumour capsule of encapsulated HCC, and (ii) the tumour junction of non-encapsulated HCC and colorectal metastasis. In addition, there was marked peritumour expression of alpha-SMA and procollagen alpha1 (I) mRNA, which diminished with distance away from the tumour in all tumour groups. The degree of expression was greatest with encapsulated HCC, less with non-encapsulated HCC and least with colorectal metastasis. This contrasted with the absence of alpha-SMA expression in normal liver from the same patients. Within the tumours, colorectal metastases differed from HCC by demonstrating marked alpha-SMA expression and collagen deposition in the septa.

CONCLUSIONS

Our findings demonstrate that activated hepatic stellate cells (i) are responsible for increased peritumour collagen production in non-encapsulated HCC and colorectal metastasis, and (ii) may be implicated in tumour capsule formation in HCC and metastasis stroma development. Thus, stellate cells may influence the local hepatic invasion by these tumours.

Intrahepatic metastases in hepatocellular carcinoma: the role of the portal vein as an efferent vessel

The mechanism and pathogenesis of the high frequency of intrahepatic metastasis in hepatocellular carcinoma (HCC) has not yet been elucidated. Two hundred and thirty one tumors (< or = 5 cm in diameter) of resected specimens of HCC were examined for the relationship between mode of tumor spread and tumor size. Efferent vessels in HCC were identified by direct injection of radiopaque material into the tumor in 23 resected liver specimens selected at random from the 231 tumors. The most frequent site for tumor spread in HCC was capsular invasion followed by extracapsular invasion, vascular invasion, and finally intrahepatic metastasis. There was a strong statistical correlation between the presence of intrahepatic metastasis and the frequency of vascular invasion (correlation coefficient = 0.998). Radiopaque material injected directly into 23 resected tumors entered only the portal vein in 17 tumors and into both the portal and hepatic veins in six tumors. In all eight patients with unresectable lesions, radiopaque media injected percutaneously into tumor nodules flowed only into the portal vein. These findings suggest that tumor spread in HCC progresses from capsular invasion to intrahepatic invasion and that the portal vein may act as an efferent tumor vessel.

Factors correlated with portal venous invasion by hepatocellular carcinoma: univariate and multivariate analyses of 232 resected cases without preoperative treatments

BACKGROUND

The postoperative intrahepatic recurrence of hepatocellular carcinoma (HCC) is high. It is difficult to distinguish whether the recurrence is metastatic or new primary lesion. To determine the malignant potential of HCC itself, we analyzed the risk factors associated with portal venous invasion since this is direct evidence of tumor invasiveness.

METHODS

Two hundred and thirty-two patients who underwent curative hepatectomy for HCC without preoperative treatments were included in this study, because preoperative treatment caused the tumor to undergo a variety of histologic change. We analyzed the risk factors linked to portal venous invasion by both univariate and multivariate analyses.

RESULTS

In an univariate analysis, tumors larger than 3 cm, high histologic grade (III or IV), the presence of fibrous capsule, necrosis, mitotic rate of more than 4/10 high power fields, peliotic change, presence of tumor giant cells, high platelet count, low level of indocyanine green retention rate at 15 minutes, and the absence of cirrhosis were significantly correlated with portal venous invasion. In multiple stepwise logistic regression analysis, tumors larger than 3 cm, high histologic grades, and the presence of fibrous capsule were strong predictors of portal venous invasion by HCC.

CONCLUSIONS

Because the blood vessels of the fibrous capsule were frequently invaded by cancer cells, it may have been possible to prevent postoperative metastatic recurrence if HCC were resected before becoming large enough to have a fibrous capsule.

Pathologic features and patient survival in hepatocellular carcinoma in relation to age

For hepatocellular carcinoma, the peak age of patients is at the sixth decade. However, the influence of age on the tumor biologic behavior and long-term patient survival is controversial. We retrospectively studied 278 patients whose hepatocellular carcinomas were surgically resected to analyze the pathologic and clinical features of the tumors and patient survival in relation to age. The patients were divided into two groups, younger than 50 years of age and older than 50 years. Ninety-seven patients were 50 years of age or under, and 181 were older than 50 years. The younger patients had: (1) more frequent hepatitis B surface antigen positivity (P = 0.022), (2) less cirrhosis (P = 0.050), (3) less tumor encapsulation, (4) a more advanced tumor stage in terms of more venous permeation (P = 0.012), more liver invasion (P = 0.010) and larger tumor (P = 0.002), and (5) a more frequently raised serum alpha-fetoprotein level (P = 0.035). In spite of the more advanced stage of the tumors, both the actuarial and disease-free survival rates did not differ significantly from those of the older group. The operative mortality rates also were similar in both groups. To conclude, there were distinct differences in the clinical and pathologic features of the tumors of patients < 50 years and those older. Although the tumors were more advanced in the younger group, the less frequently associated cirrhosis in this group might have partly compensated to result in survival rates similar to those of the older group. Because of the comparable survival rates, the treatment policy in the older group should not differ greatly from that in the younger group.

Comparison of tumor pathology with duration of survival of North American patients with hepatocellular carcinoma

BACKGROUND

Several of the large studies addressing prognosis and survival from hepatocellular carcinoma (HCC) have been from Europe and Asia, but only a few have emanated from North America. Survival statistics from other parts of the world may not be applicable to the North American population because of etiologic, demographic, cultural, lifestyle, and intangible differences. The current study investigated the survival experience and histologic correlates of North American patients with HCC and compared findings with similar studies from North America and other parts of the world.

METHODS

One thousand sixty-three patients examined during a 14-year period, met inclusion criteria for this study. Each patient was placed in one of three categories based on the duration of survival from date of diagnosis of HCC. Each tumor was examined histologically and classified according to World Health Organization criteria. Patient's sex and age at diagnosis were obtained from case records. Survival analyses and comparisons were performed using appropriate methods. Variables were tested for association using chi-square tests and randomization tests as appropriate.

RESULTS

Age, sex, tumor growth pattern, Edmondson and Steiner's nuclear grades, mitotic index, and presence or absence of tumor giant cells or portal venous invasion, were found to have statistically significant (P < 0.05) relationships with the duration of patient survival. Significantly better survival was found to be associated with female sex, low nuclear grade, low mitotic index, age at diagnosis younger than 50 years, absence of giant cells, and absence of portal venous invasion.

CONCLUSIONS

Certain histopathologic features of HCC may be useful for predicting patient survival and, thus, for empiric prognostication of these patients.

Recurrence of hepatocellular carcinoma in the liver remnant after hepatic resection

We analyzed the results of 19 patients who had intrahepatic recurrence of hepatocellular carcinoma (HCC) among 47 patients who were discharged from the hospital after having a hepatic resection in order to evaluate the factors affecting recurrence and survival. Recurrence-free survival rates were 80%, 44%, and 28% at 1, 3, and 5 years, respectively. Of the 19 patients with recurrence, 14 had multiple lesions, and 16 of the recurrences were detected within 3 years of surgery. None of the following factors correlated with recurrence: hepatic function; tumor size; presence of tumor capsule; capsular invasion; vascular invasion and intrahepatic metastasis; extent of hepatic resection; and resection with tumor-free margins. Patients having multiple recurrent HCCs, however, had larger-sized tumors at the time of resection than those with a solitary recurrence. The survival rates after recurrence were significantly better in patients with a solitary recurrence, and these patients were treated with transcatheter arterial embolization (TAE) therapy. Early detection as well as TAE for recurrent HCCs is necessary to improve long-term survival.

Predictable factors for estimating prognosis of patients after resection of hepatocellular carcinoma

BACKGROUND

Although many studies have been concerned with a clarification of the relation between various clinicopathologic factors and the prognosis of operated hepatocellular carcinoma (HCC), few studies have focused on the prognostic predictability of mitotic index and anti-hepatitis C virus (anti-HCV).

METHODS

One hundred forty cases of HCC with hepatic resection were observed from 1 to 11 years, and the relationship among various clinicopathologic factors, including the mitotic index and anti-HCV, and prognosis was evaluated.

RESULTS

Age at the time of operation, positive results for hepatitis B surface antigen or anti-HCV, accompanying cirrhosis, and the degree of tumor necrosis due to transarterial embolization did not influence the prognosis significantly. Patients with hepatitis C virus-related cases had a better prognosis than patients with hepatitis B-related cases. Patients with a single and small carcinoma smaller than 2 cm had a significantly better prognosis than those who had larger and/or multiple tumors. A better prognosis also was observed in the carcinomas with no histologic invasion into portal vein branches, low Edmondson grades, and low mitotic activities when compared with the counterpart of each group. Among these factors, the mitotic index was correlated best with prognosis in the current study.

CONCLUSIONS

The examination of mitotic index was quite simple, and the index was a helpful factor in predicting prognosis.

Hepatocellular carcinoma: prospective assessments of the T-factor with CT, US, and MR imaging

The capabilities of computed tomography (CT), ultrasonography (US), and magnetic resonance (MR) imaging were studied in order to determine the role of each of these noninvasive examinations for estimating the T-factor of hepatocellular carcinomas (HCCs). Fifty-one patients with surgically proven HCCs received CT (50 patients), US (46 patients), and MR (44 patients). The images of CT, US, and MR were prospectively evaluated for main tumor size, intrahepatic metastases, and vascular invasion, which compose the T-factor of HCC, and compared to pathological results. The sizes of the main tumor were estimated correctly by all examinations. For estimating intrahepatic metastases, US (74%) and MR (73%) were superior to CT (65%). For estimating portal invasion, CT (79%) was superior to US (70%) and MR (66%), because CT could demonstrate the segmental staining caused by portal invasion. The estimates of hepatic venous invasion were difficult during any of the examinations. We conclude that presurgical evaluations of the T-factor require the use of US and CT or MR and CT.

Antihepatitis C virus status in hepatocellular carcinoma and the influence on clinicopathological findings and operative results

Antihepatitis C virus (HCV) status was investigated in 100 patients undergoing hepatectomy for hepatocellular carcinoma (HCC) between 1980 and 1989. The clinicopathological findings and operative results, in patients with or without HCV marker, were compared retrospectively. The positivity rate of anti-HCV was 51 per cent. In this group there was a higher mean age, fewer symptoms, raised alanine aminotransferase level, higher 15-min indocyanine green clearance rate and earlier tumour stage compared with the anti-HCV negative group. Positive tumour margins and vascular invasion were seen less frequently in the anti-HCV positive group. HCC with HCV marker showed characteristic features of chronic non-A non-B hepatitis and of HCC originating from liver cirrhosis. There was a better cumulative 1-year survival rate for anti-HCV positive patients, but 3- and 5-year survival rates after hepatectomy were similar in both groups. Although HCV-related HCC had typical features of chronic non-A non-B hepatitis and a relatively early stage of tumour, biological features and operative results were similar with or without the HCV marker.

Liver resection for hepatocellular carcinoma (HCC) with direct removal of tumor thrombi in the main portal vein

Since the tumor thrombus in the main portal vein appears in the terminal stage of hepatocellular carcinoma (HCC), any attempt to remove it surgically is thought to be impractical as the malignancy itself cannot be entirely removed. During the past 5 years, we have performed tumor thrombectomy combined with hepatectomy in 29 of 298 patients with HCC. This combined therapy was initially decided upon as an emergency measure to prevent impending rupture of esophageal varices, rather than to improve patient survival. Since portal flow was obtained after removal of thrombi, this condition enabled transcatheter arterial embolization (TAE) and/or percutaneous ethanol injection therapy (PEIT). Although improved patient survival was not the primary goal of the emergency operation and there was an operative mortality of 11%, half of the other patients in the present series had unexpectedly high survival rates of 1 year (52.2%), 2 years (23.2%), and 3 years (11.6%), which were significantly higher than in patients not undergoing operation (n = 22).

Tumor encapsulation in hepatocellular carcinoma. A pathologic study of 189 cases

One hundred eighty-nine surgically resected hepatocellular carcinomas (HCC) were analyzed to study tumor encapsulation and the pathologic features that might account for the better prognosis in relation to it, and to examine the prognostic and pathobiologic significance of capsular thickness. Tumor encapsulation was found in 72 (46.8%) of the 154 cases with adequate histologic sections of the tumor-nontumor junctions. Encapsulated tumors showed a much lower incidence of direct liver invasion (P less than 0.0001), tumor microsatellites (P less than 0.0001), and venous permeation (P = 0.02) when compared with nonencapsulated ones. Significantly better disease-free and actuarial survival times were observed in patients with encapsulated tumors (medians, 9.9 and 18.3 months, respectively), compared with those with nonencapsulated ones (medians, 4.0 and 5.9 months, respectively; P = 0.0001 and 0.001, respectively). The incidence of tumor encapsulation did not increase or decrease with tumor size. Tumor encapsulation did not correlate with the presence of cirrhosis or the abundance of tumor stroma, suggesting that formation of the tumor capsule was independent of the degree of fibrosis within and outside the tumor. Among the 72 cases of encapsulated HCC, the capsular thickness ranged from 0.13 to 3.09 mm (mean +/- standard deviation = 0.87 +/- 0.59 mm), and it was unrelated to tumor size or presence of cirrhosis. Although it was apparent that a lower extensive tumor invasiveness contributed significantly to the better prognosis in encapsulated HCC, there was no correlation between capsular thickness and liver invasion, microsatellites, venous permeation, or survivals. Therefore, the thickness of tumor capsules was not helpful in prognostication.

Hepatocellular carcinoma with an unusual papillary vesicular appearance

A resected hepatocellular carcinoma with grossly papillary, whitish cut surfaces and 'vesicles' in a noncirrhotic but hepatitis B surface antigen positive liver is described. This appearance has not previously been reported in the literature. Such an unusual appearance may lead to an erroneous diagnosis by both surgeons and pathologists. Histological features and possible mechanisms for the unusual gross appearance are discussed.

Well-differentiated hepatocellular carcinoma associated with long-term survival. Report of two cases

Two cases of well-differentiated hepatocellular carcinoma (HCC) with focal biliary differentiation are presented. The distinct histological features of these neoplasms and the unusually protracted clinical course of 8 and 10 years distinguish them from previously described pathological categories of primary hepatic tumors. Electron microscopic and immunohistochemical findings support a dual hepatic and bile duct differentiation of the tumor cells. If additional examples of this tumor are found to be associated with a similarly prolonged symptom-free survival, the distinction of this entity from traditional, rapidly fatal HCC becomes important. Less aggressive therapeutic options may be entertained.

Hepatic resection for small hepatocellular carcinoma: the Queen Mary Hospital experience

The clinico-pathological features and long-term results of 39 patients with resected small hepatocellular carcinoma (HCC) managed over 19 years in Hong Kong were retrospectively studied (mean diameter +/- standard deviation: 3.6 +/- 1.3 cm). Thirty-one patients were symptomatic and the majority (n = 33) of them had cirrhosis. When compared with 182 patients with large HCC operated within the same period, these patients with small HCC had a significantly higher incidence of spontaneously ruptured lesions (p less than 0.03). Following hepatic resection-major lobectomy (n = 19) and limited hepatic resection (n = 20), operative and hospital deaths occurred in 7.7% and 12.8% of patients, respectively. The size of the lesion had little influence on prognosis. The overall survival at 1, 3, and 5 years was 59%, 28%, and 11%, respectively, which was comparable to patients with large HCC greater than or equal to 5 cm. Further stratification of these 39 patients according to a diameter of greater than 3 cm (n = 22) or less than or equal to 3 cm (n = 17) showed no difference in long-term outcome. When compared with large tumors, frequent encapsulation (p less than 0.04) and less venous permeation (p less than 0.03) were encountered in small HCC. As the extent of hepatectomy had no effect on long-term outcome, limited hepatectomy for patients with small HCC is probably the procedure of choice. A 1 cm macroscopic resection margin is apparently adequate to ensure complete histological disease clearance.

Hepatocellular carcinoma. A worldwide problem and the major risk factors

Male sex, age, cirrhosis, and HBsAg are the major risk factors for hepatocellular carcinoma (HCC). The geographic distribution of HCC is highly uneven, such that three distinct incidence areas are recognized. To clarify the reason(s) for this geographic variability of HCC, the risk factors in each incidence area were assessed. In parallel with the geographic distribution of HCC, HBsAg prevalence was highest in both HCC patients and in general population in Africa and Asia, where mothers of HCC patients are frequently HBsAg-positive, suggesting that hepatitis B virus hyperendemicity and perinatal infection account for the high HCC incidence in these areas. Cirrhosis, which is found on autopsy in 80% of the cases of HCC patients worldwide, is the most prevalent risk factor for HCC in areas where hepatitis B virus infection is less common. However, HBsAg carriage adds to the HCC risk carried by cirrhosis and explains the higher incidence of HCC in cirrhotics from Africa and Asia as well as elsewhere. Available data suggest that chronic HCV infection is a risk factor for cirrhosis and HCC. HBV vaccination should decrease HCC incidence rates worldwide; however, HCC prevention in regions where HBsAg carriage is infrequent may also require prevention of the other causes of cirrhosis in order for HCC rates to decline.

Primary liver cancer in non-cirrhotic liver. Epidemiological study based on autopsies performed in Trieste, Italy and Kurume, Japan

This study, aimed at elucidating the epidemiological features of primary liver carcinoma developing in non-cirrhotic livers, was based on 25,103 autopsies performed between 1975 and 1984 in Trieste, Italy. These autopsies correspond to approximately 70% of all deaths that occurred in this area. Various factors allegedly related to carcinomas were analysed in reference to our previous study on cirrhotic livers and in comparison with 5,603 autopsies in Kurume, Japan. There were 28 cases of hepatocellular carcinoma (HCC), 16 of cholangiocellular carcinoma (CCC) not associated with cirrhosis in Trieste, and 48 HCC and 19 CCC in Kurume. On the basis of our findings, it was concluded that cirrhosis, regardless of its cause, is the main pathogenetic factor in HCC; it is responsible for a much higher frequency (14.2:1) than in non-cirrhotic livers, as well as for early occurrence of tumours (an average of 6 years earlier in cirrhotic liver) in Trieste. Patients in Trieste were older than those in Japan, and the frequency of HCC among all autopsies was much greater in the latter. By contrast, the influence of cirrhosis on cholangiocellular carcinoma (CCC) was negligible, as such association appeared purely coincidental or absent. The incidence of CCC among autopsies was greater in Japan. Our data on CCC were not sufficient to demonstrate any clear aetiopathogenetic association between this tumour and alcohol abuse and hepatitis B virus (HBV) infection, except for a possible aetiological role of gallstones. The frequency of CCC relative to HCC was greater in Trieste than in Japan; the incidence of HCC was much less in Trieste, whereas CCC was more frequent in Japan.

Hepatectomy for large hepatocellular carcinoma: the optimal resection margin

The necessary resection margin (RM) for cure during hepatectomy for hepatocellular carcinoma (HCC) remains conjectural. From January, 1972 to June, 1988, a total of 96 patients who had complete macroscopic extirpation of their large tumor (greater than or equal to 5 cm in largest diameter) were studied retrospectively to determine the macroscopic distance of RM required to secure histological disease clearance. Positive histological RM, which was found in 31 (32.3%) patients, had significantly compromised both disease-free survival (p less than 0.04) and overall survival (p less than 0.006) of these patients. Among the 65 patients with detailed measurement of macroscopic RM, a significant reduction of residual histological disease was observed when a 0.5 cm margin had been established (p less than 0.05). Further extension of margin had no additional benefit. The presence of microsatellite (p less than 0.03) and multiple tumor nodules (p less than 0.03) was associated with an increased risk of positive histological margins among the 15 pathological parameters evaluated, including macroscopic RM. Since measurement of RM is an unreliable guide, histological confirmation is the only means for establishing the diagnosis of complete tumor clearance. Within safety limits dictated by anatomical factors and severity of underlying cirrhosis, aggressive surgery should be offered for patients with large HCC; however, resection is not advisable unless a 0.5 cm margin can be secured with certainty, especially for multinodular lesions.

Long-term survivors after hepatectomy for hepatocellular carcinoma

Sixteen long-term (more than 5 years) survivors after hepatic resection performed for hepatocellular carcinoma (HCC) from 1970 to 1988, were reviewed. The mean age of the patients was 51 years. There were 11 males and 5 females. HBs antigen was positive in 9 patients. Liver cirrhosis was associated with 11 patients but its severity was designated as Child's A in all patients except one. The mean tumour diameter was 2.8 cm and was relatively small. At the first operation, limited procedures (i.e. partial hepatectomy and subsegmentectomy) were employed in 87.5% of patients. A large percentage of tumours were located in S5 and S6 segments. A recurrence of HCC occurred in 9 patients after the first resection. A second resection was carried out in 7 patients, in 2 of which a third resection was done. Transcatheter arterial embolization (TAE) was performed on 4 patients. These results show that, in addition to detection of small tumours and early resection, repeated operation or TAE for treatment of recurrent HCC was important in achieving long-term survival after HCC resection.

Spontaneous regression of hepatocellular carcinoma

A surgically unresectable, biopsy-proven hepatocellular carcinoma (HCC) developed in a 63-year-old man with cirrhosis. He survived 24 months without treatment. During that time the tumor burden decreased as demonstrated both radiologically and by the normalization of alpha-fetoprotein levels. The patient died of complications secondary to repeated esophageal variceal hemorrhage. Necropsy demonstrated prominent, ulcerated esophageal varices and liver cirrhosis without evidence of neoplasia either grossly or on a subsequent thorough microscopic examination. This case represents the first confirmation of HCC spontaneous regression in which a primary histologic diagnosis was confirmed by immunohistochemical and flow cytometric DNA analysis, and where tumor regression was proven by a thorough necropsy examination.

Spontaneous regression of hepatocellular carcinoma

A surgically unresectable, biopsy-proven hepatocellular carcinoma (HCC) developed in a 63-year-old man with cirrhosis. He survived 24 months without treatment. During that time the tumor burden decreased as demonstrated both radiologically and by the normalization of alpha-fetoprotein levels. The patient died of complications secondary to repeated esophageal variceal hemorrhage. Necropsy demonstrated prominent, ulcerated esophageal varices and liver cirrhosis without evidence of neoplasia either grossly or on a subsequent thorough microscopic examination. This case represents the first confirmation of HCC spontaneous regression in which a primary histologic diagnosis was confirmed by immunohistochemical and flow cytometric DNA analysis, and where tumor regression was proven by a thorough necropsy examination.

Prognostic factors after hepatectomy for hepatocellular carcinomas. A univariate and multivariate analysis

The current study determines the prognostic factors after hepatectomy for hepatocellular carcinomas. The 295 patients who underwent hepatectomy from 1973 through 1987 were included for a univariate and a Cox multivariate analysis. The favoring conditions were determined as follows. The essential requirements are (1) the absence of tumor thrombi; (2) no intrahepatic metastasis, but even when present, it should be close to the main tumor and removed with a massive resection; and (3) retention rate of indocyanine green dye (ICG) at 15 minutes should be within 14 +/- 4.2% (M +/- SD) to allow that resection. The desired requirement is that the tumor size should preferably be less than 5 cm; a wider free margin from tumors (greater than or equal to 1 cm) is recommended, but not determining factor. The eligible patients, having no thrombi, no intrahepatic metastasis, a tumor size of 5 cm or less, negative surgical margin (greater than or equal to 1 cm), had achieved a 5-year survival of 78%. In conclusion, resection therapy is the first option for patients with those requirements.

Hepatocellular carcinoma in cirrhotic liver in Trieste

One hundred consecutive cases of hepatocellular carcinoma (HCC) in cirrhosis observed at autopsy were studied and their pathological aspects were compared with those reported in the literature. The results, which are representative of HCC epidemiology in a geographical area where cirrhosis is mostly due to alcohol abuse, show that similarities in the architectural pattern of HCC and weight of the liver exist between our material and samples with different aetiology and epidemiology. A relationship between the histological grade of HCC and its propensity to metastasize was demonstrated. The reported better prognosis of clear cells per se could not be confirmed, although clear cell HCC occurred exclusively in grade 2. It was also demonstrated that the relationship between grading and staging was strongly influenced by the association of HCC with cirrhosis, which is a fact that is usually overlooked by the common staging (and grading) methods.

Morphological and histological features of resected hepatocellular carcinoma in cirrhotic patients in the West

The pathological findings of 26 consecutive resections for hepatocellular carcinomas developing in cirrhotic patients were analyzed morphologically with a special interest in the presence of a capsule, vascular extension and satellite nodules. Tumor sizes varied from 2 to 11 cm. There were 20 expanding (76.9%) and six infiltrating tumors. Infiltrating tumors were significantly larger than expanding tumors (p less than 0.01). Histologically, the most common subgroups were the trabeculated pattern (65.4%) and the Edmonson-Steiner Type II (53.9%). Of the 20 expanding tumors, only six had direct spread in the liver parenchyma adjacent to the tumor (p less than 0.02). There was a significant relationship between the presence of a tumor extension in the distal portal branches and the presence of satellite nodules around the tumor (p less than 0.01). Survival at 6 months was significantly lower in patients with infiltrating (16.7%) than in those with expanding tumors (75%), (p less than 0.05). The present results indicate that pathological features of hepatocellular carcinomas in cirrhotic patients in Western countries are similar to those encountered in the East: (a) tumors are frequently encapsulated; (b) the propensity for the tumor to spread is closely related to the presence of a tumor capsule. This study suggests that a thorough preoperative search for the capsule should be made whenever resection of a hepatocellular carcinoma in a cirrhotic patient is contemplated.

Patterns of antigen expression in hepatoblastoma and hepatocellular carcinoma in childhood

Two hepatocellular carcinomas and six hepatoblastomas were examined for the presence of 13 antigens using immunoperoxidase, avidin-biotin, staining techniques. Primary antibodies were directed against alpha-fetoprotein (AFP), alpha-1-antitrypsin (AAT), lysozyme (LYS), carcinoembryonic antigen (CEA), human chorionic gonadotropin (HCG), glial fibrillary acidic protein (GFAP), neuron specific enolase (NSE), epithelial membrane antigen (EMA), hepatitis B surface antigen (HbSA), lactoferrin (LF), desmin (DES), vimentin (VIM), and keratin (KER). Except for HbSA, the antigen staining pattern was unable to differentiate between hepatoblastoma and hepatocellular carcinoma. Both neoplasms where positive for AFP, AAT, CEA, EMA, and KER; however, neither stained for GFAP, NSE, LYS, LF, HCG, or DES. Vimentin was weakly positive in those hepatoblastomas where mesenchymal tissue was present in the tumor. Only the tissue adjacent to hepatocellular carcinomas stained positively for HbSA and correlated with the elevated serum levels of HbSA.

Surgical management of space-occupying lesions in the liver

There are now many types of liver resection, depending on the amount of liver to be resected and the surgical technique selected. In the field of anatomical surgery the surgeon can choose between a major or a lesser hepatectomy and between preliminary ligation of the vessels or a primary parenchymatous resection. Sound knowledge of the anatomy is a prerequisite for anatomical surgery of this organ. Although confusion has existed as a result of differences in the nomenclature of the functional anatomy of the liver, we believe that the numerical segmental description of Couinaud is the most accurate and most easily understood. Operative ultrasonography has a fundamental role in liver surgery. It supplements information obtained by intensive preoperative investigations and enables the surgeon to make more precise and limited resections than were previously possible. It provides a greater range of options in the management of hepatocellular carcinoma. The surgeon confronted with a malignant tumour of the liver should base his decision for resection on the tumour characteristics: primary or secondary, extra- or intrahepatic spread, position, histological differentiation and presence or absence of cirrhosis. Anatomical resections should be performed providing good tumour clearance margins, while preserving as much functional parenchyma as possible. Supplementary therapies such as arterial ischaemia and chemotherapy should always be considered, but it must be borne in mind that at present hepatic resection offers the only hope of cure for malignant hepatic tumours.

Hepatoma in the noncirrhotic liver

The pathologic features, clinical presentation and natural history of hepatocellular carcinoma (HCC) developing in the noncirrhotic liver were studied in 61 patients against a background of 63 patients seen concurrently with HCC complicating cirrhosis. Noncirrhotic HCC had a bimodal age distribution, with females predominating the first age-clustering (10-50 years) and males predominating the second age-clustering (50-90 years). Cirrhotic HCC had a unimodal age distribution (40-90 years) with male dominance throughout. Estrogen exposure was noted in 57% of the noncirrhotic HCC women overall and in 80% of those in the younger age-clustering. The majority of noncirrhotic HCC presented with a single hepatic mass or a dominant primary with satellite lesions in contrast to the usual multinodular or diffuse disease seen with cirrhosis. Twenty-nine noncirrhotic patients survived complete resection of disease limited to the liver and exhibited a median survival of 2.7 years with a 5-year survival of 25%. Low histologic grade, minimal necrosis, and the absence of hemoperitoneum, hepatomegaly, and adjacent organ involvement were all favorable prognostic variable. Patients with metastatic or locally unresectable noncirrhotic HCC had a median survival of 9 months, and 24% survived in excess of 2 years. This survival experience is significantly more favorable than cirrhotic HCC patients, who had only a 1.2-month median and a 3% 2-year survival. Low histologic grade, mild mitotic activity and the presence of some fibrosis within the specimen were associated with a favorable outcome in advanced noncirrhotic HCC. The favorable prognosis and heterogeneous composition of the noncirrhotic, when compared to the cirrhotic HCC cohort, may be important considerations in the design and evaluation of future clinical trials.

Hepatocellular carcinoma imaging

Radionuclide scintigraphy can give a specific diagnosis when a hypervascular "cold" defect on colloid scans "fills in" with gallium scanning. The majority of hepatocellular carcinomas will also accumulate hepatobiliary agents especially in delayed images. Magnetic resonance imaging is superior to other modalities in providing anatomic detail, such as location and relation to vessels, needed by the surgeon in operative planning.