Claudins and tricellulin in fibrolamellar hepatocellular carcinoma

Fibrolamellar hepatocellular carcinoma is a subtype of hepatocellular carcinoma occurring in non-cirrhotic liver at a younger age. The tumor expresses both hepatocellular and cholangiocellular markers. Previously, our group described overexpression of tight junction protein claudin 4 in cholangiocellular carcinoma in contrast to hepatocellular carcinoma. In the present study, tight junction protein expressions were studied to possibly clarify bipotential lineage of fibrolamellar hepatocellular carcinoma. Eleven fibrolamellar hepatocellular carcinomas were compared with seven “conventional” hepatocellular carcinomas, seven cholangiocellular carcinomas, and five normal liver samples. By immunohistochemistry, all fibrolamellar hepatocellular carcinomas were positive for HepPar1 and cytokeratins 7, 8, and 18, but negative for cytokeratin 19. Glypican-3 gave weak staining in two cases. Expression of claudin 1 was lower, while that of claudin 2 was higher in fibrolamellar hepatocellular carcinomas than in other tumors. Claudins 3, 4, and 7 were not detectable in fibrolamellar hepatocellular carcinomas as in the majority of “conventional” hepatocellular carcinomas, contrary to high expression observed in cholangiocellular carcinomas. Focal or diffuse claudin 5 expression was detected in nine of 11 fibrolamellar hepatocellular carcinomas contrary to other tumors. Tricellulin was significantly downregulated in all tumors compared with normal liver. Our findings showed claudins to exhibit specific expression patterns in fibrolamellar hepatocellular carcinomas not observed in other primary liver tumors, with unique claudin 5 expression and pattern features similar to common hepatocellular carcinoma, but different from cholangiocellular carcinoma. This is the first report describing the loss of tricellulin expression in human hepatic tumors.     

Clinicopathologic features and survival in fibrolamellar carcinoma: comparison with conventional hepatocellular carcinoma with and without cirrhosis.

Fibrolamellar carcinoma arises in noncirrhotic livers of young individuals and has been considered to be less aggressive than conventional hepatocellular carcinoma. This study compares survival and clinicopathologic features of fibrolamellar carcinoma with hepatocellular carcinoma arising in noncirrhotic and cirrhotic livers. Clinical and pathologic features including age, gender, tumor size, stage and survival were recorded in 20 resected cases of fibrolamellar carcinoma. Survival was compared with resected hepatocellular carcinoma without (n=32) and with cirrhosis (n=30). Proliferative activity was determined by immunohistochemistry for Ki-67. In all, 12 (60%) patients with fibrolamellar carcinoma died during follow-up; the 5-year survival was 45%. Mortality in fibrolamellar carcinoma was higher with metastatic disease at presentation (6/7, 86% vs 5/13, 39%, P=0.06). Age, gender and tumor size did not correlate with survival. The 5-year (45 vs 56%, P=0.4) as well as overall survival (40 vs 56.3%, P=0.3) was similar in fibrolamellar carcinoma and hepatocellular carcinoma without cirrhosis. The 5-year and overall survival in hepatocellular carcinoma with cirrhosis was 27 and 23.3%, respectively, which was not significantly different compared to fibrolamellar carcinoma (P=0.2). Among the cases without metastases at presentation, 5-year survival in fibrolamellar carcinoma (62%) and hepatocellular carcinoma without cirrhosis (57%) was significantly better (P=0.03) than hepatocellular carcinoma with cirrhosis (27%). The mean Ki-67 index was similar in all three groups (P=0.1). In conclusion, fibrolamellar carcinoma is an aggressive neoplasm with 45% 5-year survival and overall mortality of 60%. Nearly half the patients develop lymph node or distant metastasis. The prognosis of fibrolamellar carcinoma is similar to conventional hepatocellular carcinoma. Among nonmetastatic cases, the prognosis is better in fibrolamellar carcinoma and hepatocellular carcinoma without cirrhosis compared to hepatocellular carcinoma with cirrhosis. The better outcome in fibrolamellar carcinoma appears to be due to the absence of cirrhosis rather than its distinct clinicopathologic features.     

Fibrolamellar variant of hepatocellular carcinoma

A fibrolamellar variant of hepatocellular carcinoma with metastases in 2 regional lymph nodes was surgically removed from a girl, 17 years of age. This type of tumor has a typical histological pattern. Prognosis is found to be better than that of the common hepatocellular carcinoma.     

Fibrolamellar hepatocellular carcinoma occurring 5 years after hepatocellular adenoma in a 14-year-old girl: a case report with comparative genomic hybridization analysis

An unusual case of fibrolamellar carcinoma of the liver developed 5 years after removal of a hepatocellular adenoma in a 14-year-old girl belonging to a family with Carney syndrome. Both tumors were studied by light and electron microscopy, flow cytometry, and comparative genomic hybridization. The first tumor, removed at the age of 9, was a bulky well-circumscribed liver mass composed of large eosinophilic cells with a focal pseudoglandular pattern but without cytologic atypia or sclerosis. A diagnosis of hepatocellular adenoma was rendered. Five years later, another hepatic tumor was removed from the right lobe. Microscopic examination revealed polygonal cells, each with a large amount of eosinophilic cytoplasm and a round nucleus with a conspicuous nucleolus. These cells were arranged in nests and strands and separated by bands of dense fibrous tissue, leading to a diagnosis of fibrolamellar carcinoma. Comparative genomic hybridization analysis revealed no genetic alteration in the adenoma; however, several chromosomal aberrations (loss of chromosome regions 1p and 4p and gains of chromosome regions 6q, 13q, and Xq) were detected in the fibrolamellar carcinoma. To our knowledge, this is the first report of an association between hepatocellular adenoma and fibrolamellar carcinoma.     

Clinical and pathological evaluation of fibrolamellar hepatocellular carcinoma: a single center study of 21 cases

OBJECTIVES:

Fibrolamellar hepatocellular carcinoma is a rare primary malignant liver tumor that differs from conventional hepatocellular carcinoma in several aspects. The aim of this study was to describe the clinical, surgical and histopathological features of fibrolamellar hepatocellular carcinoma and to analyze the factors associated with survival.

METHODS:

We identified 21 patients with histopathologically diagnosed fibrolamellar hepatocellular carcinoma over a 22-year period. Clinical information was collected from medical records and biopsies, and surgical specimens were reviewed.

RESULTS:

The median age at diagnosis was 20 years. Most patients were female (67%) and did not have associated chronic liver disease. Most patients had a single nodule, and the median tumor size was 120 mm. Vascular invasion was present in 31% of patients, and extra-hepatic metastases were present in 53%. Fourteen patients underwent surgery as the first-line therapy, three received chemotherapy, and four received palliative care. Eighteen patients had “pure fibrolamellar hepatocellular carcinoma,” whereas three had a distinct area of conventional hepatocellular carcinoma and were classified as having “mixed fibrolamellar hepatocellular carcinoma.” The median overall survival was 36 months. The presence of “mixed fibrolamellar hepatocellular carcinoma” and macrovascular invasion were predictors of poor survival. Vascular invasion was associated with an increased risk of recurrence in patients who underwent surgery.

CONCLUSION:

Fibrolamellar hepatocellular carcinoma was more common in young female patients without chronic liver disease. Surgery was the first therapeutic option to achieve disease control, even in advanced cases. Vascular invasion was a risk factor for tumor recurrence. The presence of macrovascular invasion and areas of conventional hepatocellular carcinoma were directly related to poor survival.     

Fibrolamellar hepatocellular carcinoma: a case report

A 6-year-old Malay boy presented with fever and abdominal pain for 2 months. Computerised tomography showed a nodular mass in the left lobe of the liver. There was also portal vein thrombosis on the left side. Serum alpha-fetoprotein was not elevated and Hepatitis B antigen was negative. Biopsy of the liver mass led to a histological diagnosis of fibrolamellar hepatocellular carcinoma. In view of extensive tumour involvement, he could not be operated on but was treated with chemotherapy. However, the tumour did not respond. While this is expected for fibrolamellar hepatocellular carcinoma, the possibility of the tumour having a component of ordinary hepatocellular carcinoma could not be excluded as the tumour was not resected. Fibrolamellar hepatocellular carcinoma is a rare histological subtype of hepatocellular carcinoma, associated with a better prognosis. It affects the younger age group and has no association with cirrhosis, hepatitis B virus infection or exposure to oral contraceptives, all of which are implicated in ordinary hepatocellular carcinoma. Serum alpha-fetoprotein level is usually within normal limits and other laboratory values are not contributory to the diagnosis. The diagnosis is usually suggested by radiographic studies viz. CT scan of the abdomen, which would show an irregular non-homogenous mass in the liver, and confirmed by histological examination. The most characteristic microscopical feature is fibrosis arranged in a lamellar fashion around polygonal and deeply eosinophilic neoplastic hepatocytes.     

HGF, MET, and matrix-related proteases in hepatocellular carcinoma, fibrolamellar variant, cirrhotic and normal liver.

Fibrolamellar variant is an uncommon subcategory of hepatocellular carcinoma with a better prognostic outcome. Proteinases and growth factors that are involved in the remodeling of extracellular matrix may influence the behavior of cancers. To determine whether these factors contribute to the distinct etiologies of fibrolamellar hepatocellular carcinoma and traditional hepatocellular carcinoma, we assayed hepatocyte growth factor, the hepatocyte growth factor receptor, and two hepatocyte growth factor activators, hepatocyte growth factor activator and urokinase-type plasminogen activator, in hepatocellular carcinoma, fibrolamellar hepatocellular carcinoma, cirrhotic liver and normal liver. In addition, we examined the urokinase-type plasminogen activator receptor, the type 1 plasminogen activator inhibitor, plasmin, fibrinogen, and the type IV matrix metalloproteinases. Eighteen hepatocellular carcinomas and 11 fibrolamellar hepatocellular carcinomas were obtained as paraffin embedded sections from the University of Pittsburgh Department of Pathology. Frozen tissues from a subset of cases (9 hepatocellular carcinomas, 4 fibrolamellar hepatocellular carcinomas, 12 cirrhotic livers and 2 normal livers) were also available for analysis. Antibodies against urokinase-type plasminogen activator, urokinase-type plasminogen activator receptor, hepatocyte growth factor and hepatocyte growth factor receptor were used to analyze immunoperoxidase stained slides from the paraffin blocks. Western blot analyses using antibodies against hepatocyte growth factor, hepatocyte growth factor receptor, phosphotyrosine, hepatocyte growth factor activator, urokinase-type plasminogen activator receptor, urokinase-type plasminogen activator, plasminogen activator inhibitor-1, fibrinogen and plasmin were performed on membrane-enriched fractions from the frozen tissue, as was collagen zymography for matrix metalloproteinase-2 and matrix metalloproteinase-9. The most notable findings are as follows: hepatocyte growth factor activator was only detected in malignant tissue but not cirrhotic liver or normal liver. Although hepatocyte growth factor was detected in most samples, it was significantly elevated in 5/9 hepatocellular carcinomas. Furthermore, 8/9 fibrolamellar hepatocellular carcinomas demonstrated hepatocyte growth factor receptor levels similar to normal, whereas 8/9 hepatocellular carcinomas and 11/12 cirrhotic livers exhibited either an increase or decrease. In contrast, active matrix metalloproteinase-2, which was absent in normal liver, was elevated in fibrolamellar hepatocellular carcinoma as compared to cirrhotic liver and conventional hepatocellular carcinoma. Surprisingly, 10/12 cirrhotic livers and 2/4 fibrolamellar hepatocellular carcinomas but only 1/9 hepatocellular carcinomas were enriched for plasmin. The combined data suggest that the hepatocyte growth factor and plasmin systems tend to be operative in hepatocellular carcinoma and cirrhotic liver, more than fibrolamellar hepatocellular carcinoma. Furthermore, matrix turnover appears to be a more prominent feature of fibrolamellar hepatocellular carcinoma. These findings provide insight into the behavioral differences between hepatocellular carcinoma and the fibrolamellar variant.     

Fibrolamellar hepatocellular carcinoma: a report of a resected case with an electron microscopic and flow cytometric analysis [corrected

A resected case of fibrolamellar (FLC) and hepatocellular (HCC) combined carcinoma arising in a non-cirrhotic liver of a 29 year old female is reported, including results of the preoperative percutaneous aspiration biopsy, which suggested FLC, and postoperative electron microscopic and flow cytometric analysis. Sections of the resected massive tumor of the left lobe of the liver showed hepatocellular carcinoma accompanying the fibrolamellar carcinoma element which was composed of tumor cells with eosinophilic granular cytoplasm and unique cytoplasmic vacuoles (pale bodies). Lamellar fibrosis was present in the stroma, while no macroscopic central scar was demonstrated. Electron microscopy showed typical features of FLC and flow cytometric DNA analysis indicated diploid DNA pattern with a low proliferation rate. A common HCC element with trabecular structure also existed at the periphery of the tumor. No apparent etiologic agent for the development of hepatic neoplasm was indicated in the history of this patient. She had been without recurrence for about 3 years after extended left lobectomy, when local recurrence was revealed. The recurrence has been treated with chemoembolization and percutaneous ethanol infusion several times up till the present. This case reconfirms the importance of the pathological diagnosis of FLC to promote surgical intervention.     

裸鼠皮下种植性肝癌模型的建立

背景：目前采用Huh7肝癌细胞在BALB/c裸小鼠皮下种植性成瘤的报道较多,但对其成瘤后稳定性的研究较少。 目的：建立稳定的皮下种植性裸鼠肝癌模型。 方法：取1.5×10⁶个对数期细胞Huh7肝癌细胞,种植于裸鼠皮下。成瘤后从体质量、大体形态,肿瘤生长情况,反转录-聚合酶链式反应,苏木精-伊红染色及免疫组织化学多方面进行稳定性及病理学特征鉴定。 结果与结论：肿瘤形成的潜伏期约12 d,肿瘤成功率为92.8%。种植肿瘤组小鼠体质量较正常对照小鼠明显减轻,肿瘤生长迅速,甲胎蛋白基因及蛋白强阳性表达,细胞分裂明显。表明成功建立了稳定的裸鼠皮下种植性肝癌模型。     

Hyaline globules and intracellular lumina in a hepatocellular carcinoma

The authors report ultrastructural findings on the morphogenesis of hyaline globular inclusions (HG) of a moderately well-differentiated hepatocellular carcinoma, with the features of a fibrolamellar variant. Pale blue cytoplasmic inclusions (pale bodies) of the tumor cells were shown to be intracellular lumina lined with numerous microvilli. Our findings suggest that HG were formed apparently by the successive deposition of fine granular materials in the lumina. Small accumulations were present in the intracellular lumina, which were seen on light microscopy as central hyaline cores of pale inclusions. Larger globular deposits, corresponding to HG and presumably mature ones, were lined closely with membranes devoid of microvilli that were probably shed intraluminally. Our observation was discussed with relation to the previous findings on the inclusions.     

Combined hepatocellular carcinoma and osteoclast-like giant cell tumor of the liver: Possible clue to histogenesis

Hepatic giant cell tumor is extremely rare, and only five cases have been reported of overt hepatocellular carcinoma, thus its histogenesis is controversial. Herein is reported a case of simultaneous hepatocellular carcinoma and osteoclast-like giant cell tumor in a single tumor. A liver tumor was found in a 74-year-old woman. Histologically the tumor consisted of two distinct components: mononuclear and multinuclear giant cells with osteoclastic giant cells, and a conventional hepatocellular carcinoma. The boundary between the two components showed transitional features. Immunohistochemistry showed that the osteoclast-like giant cells were CD68 and vimentin positive, but cytokeratin and AFP negative, while spindle-shaped cells were positive only for vimentin. In a portion of the hepatocellular carcinoma the cells were cytokeratin-8 and AFP positive. Ki-67 positivity was 10% for the hepatocellular carcinoma, 60% for the spindle-shaped cells, and 0% for the giant cells. It is possible that the tumor might have had a hepatocellular carcinoma origin, given the more highly proliferative sarcomatous changes and reactive osteoclast-like cells. This case provides a clue to the histogenesis of hepatic giant cell tumors.     

Diagnostic approach to well-differentiated hepatocellular carcinoma

Well-differentiated hepatocellular mass-lesions in non-cirrhotic livers have a differential diagnosis of focal nodular hyperplasia, regenerative hepatic pseudotumors, hepatic adenoma, hepatocellular carcinoma, and fibrolamellar carcinoma. Despite significant advances in characterizing these pseudotumors and tumors, they remain a diagnostic challenge, especially on needle biopsy. This review focuses on a systematic diagnostic approach, one that allows confident diagnosis of these lesions.     

Epigenetic instability is rare in fibrolamellar carcinomas but common in viral-associated hepatocellular carcinomas.

Fibrolamellar carcinomas have a unique predilection for younger individuals and arise in livers without recognizable liver disease. In contrast to typical hepatocellular carcinomas, fibrolamellar carcinomas show few chromosomal changes and lack mutation in key genes such as TP53 and CTNNB1. Epigenetic instability, manifesting as methylation of important tumor suppressor gene promoters, has not been investigated in fibrolamellar carcinomas. Thus, the methylation status of 11 tumor suppressor gene promoters was investigated using methylation-specific PCR: RASSF1, CDH1, CDKN2B, HPP1, CDKN2A, GSTP1, P16, RARA, FLJ13081, SOCS1, and TP53. Nine fibrolamellar carcinomas were studied including primary tumors (N=5) and metastatic deposits (N=4) along with control groups of typical hepatocellular carcinoma arising in livers with (N=21) and without cirrhosis (N=10). In fibrolamellar carcinomas, RASSF1A and CDH1 (e-cadherin) were the most commonly methylated genes with 80-100% of tumors methylated. However, overall fibrolamellar carcinomas showed low levels of methylation with no differences between fibrolamellar carcinomas and their paired normal livers. However, fibrolamellar carcinomas showed significantly less methylation than hepatocellular carcinomas that arose in the background of viral cirrhosis. Overall, methylation was most strongly linked to viral cirrhosis. In conclusion, fibrolamellar carcinoma shows low levels of methylation. In contrast, higher levels of promoter methylation are associated with hepatocellular carcinomas that arise in the setting of viral induced cirrhosis.     

骨髓间充质干细胞对高转移肝癌模型的干预

背景：骨髓间充质干细胞具备化学趋向性和归巢作用,对于促进患者免疫系统的重建、消除残留病灶及防止复发转移具有良好的效果。 目的：观察人骨髓间充质干细胞移植入动物模型对肝癌组织的影响情况及对肝癌转移潜能影响。 方法：制作高转移潜能动物模型,实验组在接种肿瘤后第7日开始尾静脉注射骨髓间充质干细胞,5×105/次,2次/周;对照组尾静脉注射骨髓间充质干细胞培养液,0.2 mL/次,实验开始后每4 d用测量肿瘤体积,肿瘤接种后14 d(2周),21 d(3周),28 d(4周),35 d(5周),42 d(6周)处死动物,称质量,取瘤块,称瘤质量,计算肿瘤质量抑制率。PCR检测动物模型标本转移相关因子骨桥蛋白、骨唾液蛋白、整合素αⅤ基因的表达,及肿瘤标本凋亡相关因子bcl-2、bax、caspase3基因的表达。 结果与结论：第3周时肿瘤的质量抑制率效果最好,随着时间的延长,肿瘤的抑制率逐渐下降。肝癌转移相关的生物学指标均呈逐渐下降趋势,代表肿瘤凋亡指标的因子呈两极分化表现,抗凋亡bcl-2因子呈逐渐下降的趋势,凋亡因子bax、caspase3呈逐渐升高的趋势。骨髓间充质干细胞对肝癌动物模型肿瘤抑制效能随时间而变化,骨髓间充质干细胞移植后第3周对肝癌抑制效果最显著,随着时间的延长,抑制效能减弱。骨髓间充质干细胞对肝癌的转移潜能具有抑制作用。中国组织工程研究杂志出版内容重点：干细胞;骨髓干细胞;造血干细胞;脂肪干细胞;肿瘤干细胞;胚胎干细胞;脐带脐血干细胞;干细胞诱导;干细胞分化;组织工程全文链接：     

Fibrolamellar hepatocellular carcinoma in ascitic fluid: A case report with cytohistological correlation

The fibrolamellar variant of hepatocellular carcinoma (FL‐HCC) is distinguished from other hepatocellular carcinoma's (HCC) by its unique clinical and pathological features. Cytological features of this tumor on fine needle aspiration have been described earlier. We report a rare case of a 17‐year‐old African American male with metastatic FL‐HCC, diagnosed by body fluid cytology. The patient presented with ascites and computed tomography (CT) scan revealed multiple omental masses and liver lesions. The fluid sample was obtained along with the omental biopsy and was found positive for metastatic fibrolamellar hepatocellular carcinoma. The fluid cytology showed atypical polygonal cells with enlarged nuclei, prominent nucleoli, and abundant granular cytoplasm. Cytomorphologic features of FL‐HCC presenting in body fluids have been rarely described before. This case enriches the cytopathology literature by providing awareness of this tumor presenting as metastasis in body fluids, especially in young individuals with liver lesions. Presence of a concurrent biopsy specimen provided cytohistological correlation, as it remains the gold standard for the accuracy and reliability of cytological diagnoses. Diagn. Cytopathol. 2016;44:757–760. © 2016 Wiley Periodicals, Inc.     

Fibrolamellar carcinoma: A histologically unique tumor with unique molecular findings

Fibrolamellar carcinoma is a unique type of hepatocellular carcinoma with a distinctive predilection for young patients without underlying liver disease, characteristic large neoplastic cells with intervening, dense fibrosis, co-expression of keratin 7 and CD68 and activation of protein kinase A (most often by formation of DNAJB1-PRKACA). Fibrolamellar carcinoma has a similar prognosis to conventional hepatocellular carcinomas arising in non-cirrhotic livers. The current American Joint Cancer Committee staging system does not provide optimal stratification of patients with fibrolamellar carcinoma and an alternate systems should be considered in the future. The only effective treatment for fibrolamellar carcinoma is complete resection. Novel therapies may be on the horizon as investigation into the molecular biology of fibrolamellar carcinoma continues.     

Fibrolamellar Carcinoma of Liver: A Primary Malignant Oncocytic Carcinoid?

Immunohistochemical and ultrastructural findings in two cases of fibrolamellar carcinoma of the liver and two cases of hepatocellular carcinoma of the common histologic type are described. Ultrastructural examination of both cases of fibrolamellar carcinoma revealed the presence of neurosecretory (NS) granules which were sparse in some cells and abundant in others. Many of the tumor cells had a distinct oncocytic appearance with abundant mitochondria. A portion of the glutaraldehyde-fixed neoplasm was processed for the uranaffin reaction (an ultrastructural cytochemical stain specific for the NS granules of neuroendocrine tissue). Abundant uranaffin-positive granules were found in the neoplastic cells of both cases of fibrolamellar carcinoma, whereas no uranaffin-positive granules were found in hepatocellular carcinoma of the common histologic type. There was no statistical difference in the mean diameter of the uranaffin-positive granules measured from both cases. Immunohisto-chemistry revealed the presence of neuron-specific enolase (NSE) and serotonin in one of the two cases of fibrolamellar carcinoma and no NSE staining in two cases of hepatocellular carcinoma of the common histologic type. These findings suggest that some liver tumors presenting histologically as fibrolamellar carcinoma may be neuroendocrine in nature.     

Long-Spacing Collagen and Proteoglycans in Pathologic Tissues

Immunohistochemical and ultrastructural findings in two cases of fibrolamellar carcinoma of the liver and two cases of hepatocellular carcinoma of the common histologic type are described. Ultrastructural examination of both cases of fibrolamellar carcinoma revealed the presence of neurosecretory (NS) granules which were sparse in some cells and abundant in others. Many of the tumor cells had a distinct oncocytic appearance with abundant mitochondria. A portion of the glutaraldehyde-fixed neoplasm was processed for the uranaffin reaction (an ultrastructural cytochemical stain specific for the NS granules of neuroendocrine tissue). Abundant uranaffin-positive granules were found in the neoplastic cells of both cases of fibrolamellar carcinoma, whereas no uranaffin-positive granules were found in hepatocellular carcinoma of the common histologic type. There was no statistical difference in the mean diameter of the uranaffin-positive granules measured from both cases. Immunohisto-chemistry revealed the presence of neuron-specific enolase (NSE) and serotonin in one of the two cases of fibrolamellar carcinoma and no NSE staining in two cases of hepatocellular carcinoma of the common histologic type. These findings suggest that some liver tumors presenting histologically as fibrolamellar carcinoma may be neuroendocrine in nature.     

Morphology and other prognostic factors of hepatocellular carcinoma.

OBJECTIVE: Hepatocellular carcinoma is a malignancy found worldwide that has typically poor prognosis despite treatment. Although several studies have dealt with prognostic factors, just a few detailed analyses of large series correlating the pathology of hepatocellular carcinoma with prognosis are available. The present study was undertaken to address this limitation. PATIENTS AND METHODS: Our prior clinical study described 432 patients, but sufficient tissue was available for evaluation in only 299 patients. Of these, 224 samples contained primary hepatocellular carcinoma, while the remainder contained only metastatic tumor. Characteristics evaluated included degree of tumor differentiation, associated cirrhosis or hepatitis, presence of cytoplasmic inclusion bodies, and blood vessel invasion by the neoplasm. RESULTS: Of the 224 patients, 71% were male, 65% white, and 73% over the age of 45 years. Ninety-one percent were from North America. A total of 42 patients were found to have cirrhosis. Thirty-five percent had cytoplasmic inclusion bodies, and 25% showed evidence of blood vessel invasion. Tumor response rates (tumor shrinkage) were low (8%) regardless of treatment. Presence of cytoplasmic eosinophilic inclusion bodies and blood vessel invasion were not associated with increased survival. Some histopathologies (pelioid, spindle cell, fibrolamellar) were associated with a better prognosis. Patients with a predominant trabecular pattern (43%) did particularly poorly. Although sex was significantly associated with survival using a univariate analysis, this effect disappeared in a multivariate Cox model that adjusted simultaneously for other factors. CONCLUSION: This investigation suggests that histologic subtype and clinical features may provide useful prognostic information in hepatocellular carcinoma. Poorer survival was observed in males, older patients with poorly differentiated tumors, or when associated with cirrhosis. Age younger than 45 years was a good prognostic factor, and presence of cirrhosis had an adverse effect on survival.