Clear cell carcinoma of the liver: a comparative immunohistochemical study with renal clear cell carcinoma

Multimodal imaging findings of primary liver clear cell carcinoma: a case presentation

Primary clear cell carcinoma of liver (PCCCL) is a special and relatively rare subtype of hepatocellular carcinoma (HCC), which is more common in people over 50 years of age, with a preference for men and a history of hepatitis B or C and/or cirrhosis. Herein, we present a case of a 60-year-old woman who came to our hospital for medical help with right upper abdominal pain. The imaging examination showed a low-density mass in the right lobe of his liver. In contrast enhanced computed tomography (CT) or T1-weighted imaging, significant enhancement can appear around the tumor during the arterial phase, and over time, the degree of enhancement of the tumor gradually decreases. The lession showed obviously increased fluorine-18 fluorodeoxyglucose (18F-FDG) uptake on positron emission tomography/CT. These imaging findings contribute to the diagnosis of PCCCL and differentiate it from other types of liver tumors.

Arginase-1 is More Specific Than Hepatocyte Paraffin 1 for Differentiating Hepatocellular Carcinomas With Cytoplasmic Clearing from Nonhepatocellular Clear Cell Tumors in Liver Biopsies

Arginase-1 (Arg1) and hepatocyte paraffin antigen 1 (HepPar1) are specific and sensitive markers of hepatocellular differentiation. HepPar1 is a granular cytoplasmic immunostain that may be negative in hepatocellular carcinoma (HCC) with cytoplasmic clearing. Arg1 shows uniform cytoplasmic positivity and frequent nuclear positivity. This study was undertaken to determine the staining pattern of Arg1 in HCC with cytoplasmic clearing and compare its use to HepPar1. Fifteen resected HCCs with cytoplasmic clearing and 31 biopsies of clear cell liver tumors (14 HCCs and 17 nonhepatocellular tumors) were identified. Resections were stained with Arg1 to characterize the pattern, intensity, and extent of Arg1 positivity. Biopsies were stained with Arg1 (n=31) and HepPar1 (n=28). In all, 13/15 resected and 11/14 biopsied HCCs with cytoplasmic clearing showed nuclear positivity for Arg1. Both Arg1 and HepPar1 stained significantly more HCCs than nonhepatocellular tumors (13/14 and 11/12, respectively, with P <0.0001 and P =0.0018, respectively). However, HepPar1 stained significantly more nonhepatocellular tumors (5/12) than Arg1 (0/17, P =0.0445). Arg1 frequently displayed nuclear positivity, and interobserver agreement was better for Arg1 ( K =0.93 vs. 0.79). Overall, Arg1 is more specific than HepPar1 for differentiating HCC with cytoplasmic clearing from nonhepatocellular clear cell tumors in the liver. Its staining characteristics, including nuclear positivity, make it easier to interpret in combination with morphology, improving interobserver variability, and it stains significantly fewer mimics than HepPar1.

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.

A case of clear cell-hepatocellular carcinoma accidentally found in the gallbladder wall after laparoscopic resection of gallbladder empyema: Beware of the liver bed

INTRODUCTION AND IMPORTANCE

Hepatocellular carcinoma (HCC) invading the gallbladder is a rare scenario, even in the context of an advanced tumor. The clear cell variant of HCC (CC-HCC) is also rare. However, CC-HCC is more frequent in women and those with liver cirrhosis, and the standard definition is the presence of transparent cytoplasm in at least 50 % of tumor cells.

CASE PRESENTATION

An accidental finding of HCC was made during histological examination of a gallbladder empyema specimen from a 74 year-old male patient. The tumor was found to be invading the wall of the gallbladder. On post-operative imaging, the HCC was identified in liver segments 4b, 5 and 6, with extensive portal vein thrombosis; without other distant spread. The tumor in our case was almost exclusively comprised of clear cells (>90 %); therefore, it was classified as CC-HCC.

CLINICAL DISCUSSION

Tumors are rarely discovered along with acute cholecystitis. Furthermore, HCC rarely invades the wall of the gallbladder. HCC with clear cell histology should be distinguished from other regional and metastatic tumors of similar morphology.

CONCLUSION

In this particular case, we provide an unusual circumstance in which HCC invaded the gallbladder wall and was found by chance in a specimen obtained after a cholecystectomy. Malignancy remains an under-recognized clinical scenario that is easily overlooked when assessing patients presenting with cholecystitis. We report our case with an additional focus on the findings of computed tomography (CT) as well as the clinicopathological characteristics pertinent to this distinctive histologic pattern of CC-HCC.

Hepatocellular Carcinoma: Does the Background Liver With or Without Cirrhosis Matter?

OBJECTIVES

The pathologic differences between hepatocellular carcinoma (HCC) arising in noncirrhotic and cirrhotic livers have not been well studied.

METHODS

We performed a retrospective analysis of 378 HCC cases (95 in noncirrhotic, 283 in cirrhotic livers) from pathology archives (2010-2017).

RESULTS

Patients without cirrhosis were more likely to have hepatitis B (13.68% vs 2.83%, P < .001) or no known liver disease (30.53% vs 4.24%, P < .001), while hepatitis C was more common in patients with cirrhosis (65.72% vs 30.53%, P < .001). HCCs in noncirrhotic livers were larger in size (P < .001); were more likely to have a macrotrabecular histologic pattern (13.68% vs 4.95%, P < .01); were more likely to have fibrolamellar (3.16% vs 0%, P = .02), macrotrabecular-massive (13.68% vs 6.01%, P = .03), and clear cell (16.84% vs 6.71%, P < .01) subtypes; have a higher histologic grade (P < .01); be anaplastic tumor cells (P < .001); have a higher rate of vascular invasion (P < .01); and have a higher tumor stage (P = .04).

CONCLUSIONS

The findings indicate that HCCs in noncirrhotic livers demonstrate a larger tumor size; have a more macrotrabecular histologic pattern; have fibrolamellar, macrotrabecular-massive, and clear cell subtypes; have a higher tumor grade and stage; have a higher rate of vascular invasion; and have more anaplastic tumor cells compared with cirrhotic livers. Further studies to explore different pathways that promote oncogenesis in noncirrhotic livers are needed to better understand the pathogenesis of HCC.

Pathological and Cytological Studies on Hepatocellular Carcinoma in Cattle Slaughtered at Bishoftu Elfora Abattoir, Central Ethiopia

Hepatocellular carcinoma (HCC) is one of the most common neoplasms that has been described in many domestic animal species. Hence, the disease has significant economic importance; thus, this study aimed to describe the cytopathological characteristics of hepatocellular carcinomas in cattle slaughtered at Bishoftu Elfora Abattoir, Central Ethiopia. A cross-sectional study design with a purposive sampling technique was performed from October 2017 to May 2018 using macroscopic, histopathologic, and cytological methods. For that matter, a total of sixty cattle were assessed for the presence of a hepatic tumor; however, only 1/60 (0.6%) case was found to be affected by hepatocellular carcinomas. On gross examination, hepatocellular carcinomas exhibited soft, white, multifocal nodules (10–40 mm in diameter) on different lobes of the liver. On the cut surface, the tumor revealed a sharply circumscribed border and was divided into lobules by thin connective tissue. The central zone of the tumors exhibited depression with a whitish fibrous area. Moreover, on histopathology, the tumors divulged unencapsulated carcinomatous lesions consisting of a thick, compact, somewhat ambiguous trabecular pattern of arrangement that was unglued by thin collagenous stroma. Cytological studies suggest that the tumor cells showed anisocytosis, anisokaryosis, prominent nucleoli, multinuclearity, palisading arrangements of neoplastic cells, increased N : C ratios, light eosinophilic cytoplasm, high mitotic index, and cytoplasmic and intranuclear vacuoles. In conclusion, cytopathological findings support a diagnosis of HCC in the liver; thus, further studies with a large sample size and use of immunohistochemistry are important for further characterization of hepatocellular carcinomas in cattle.

An update on subtypes of hepatocellular carcinoma: From morphology to molecular

The morphologic spectrum of hepatocellular carcinoma (HCC) is quite broad. While in about one-third of cases, the neoplasms can be categorized into meaningful subtypes based on morphology, a vast majority of these neoplasms are morphologically heterogeneous. With extensive tumor profiling, data has begun to emerge which can correlate specific morphologic features with underlying molecular signatures. A true morphologic subtype not only has reproducible H & E features, further supported by specific immunohistochemical or molecular signatures, but also has specific clinical implications and prognostic associations. Eight such morphologic subtypes are recognized by the 2019 WHO classification of tumors with a few more additional subtypes described in the literature. The goal of this review is to familiarize the reader with the morphologic subtypes and elaborate on the clinical and molecular associations of these neoplasms.

Simultaneous renal clear cell carcinoma and primary clear cell carcinoma of the liver: A case report

RATIONALE

Double primary clear cell carcinomas of the liver (PCCCL) and kidney are extremely rare; moreover, there have been no reported cases of adrenal metastasis from primary clear cell tumors of the liver.

PATIENT CONCERNS

A 47-year-old male patient was admitted to our clinic with space-occupying lesions in the left kidney and liver during a regular medical examination.

DIAGNOSES

The tumors in the kidney and liver were diagnosed as primary clear cell carcinoma by histopathological examination.

INTERVENTIONS

The patient subsequently underwent nephron-sparing surgery of the left kidney and radical partial excision of the right liver lobe by laparoscopic surgery. Transcatheter arterial chemoembolization (TACE) was performed for the patient 2 weeks after tumor resection. One month after the operation, the patient started adjuvant therapy with sorafenib (400 mg twice per day orally). However, follow-up CT imaging revealed a solid mass measuring 1.9 × 2.0 × 2.0 cm in the right adrenal gland at 2 months postoperatively, and then the patient underwent radiofrequency ablation (RFA) for the right adrenal tumor.

OUTCOMES

The patient remained cancer free for 2 years following the diagnosis despite early right adrenal metastasis.

LESSONS

Hepatocyte immunostaining is sufficient for the diagnosis of PCCCL.

Hepatocellular Carcinoma: Role of Pathology in the Era of Precision Medicine

Hepatocellular carcinoma (HCC) is a morphologically heterogeneous tumor with variable architectural growth patterns and several distinct histologic subtypes. Large-scale attempts have been made over the past decade to identify targetable genomic alterations in HCC; however, its translation into clinical personalized care remains a challenge to precision oncology. The role of pathology is no longer limited to confirmation of diagnosis when radiologic features are atypical. Pathology is now in a position to predict the underlying molecular alteration, prognosis, and behavior of HCC. This review outlines various aspects of histopathologic diagnosis and role of pathology in cutting-edge diagnostics of HCC.

Hepatocyte paraffin 1 and arginase-1 are effective panel of markers in HBV-related HCC diagnosis in fine-needle aspiration specimens

Objective

In order to make successful treatment for HBV-related hepatocellular carcinoma, an early diagnosis is necessary. In this research we aimed to evaluate the IHC staining pattern of Hepatocyte paraffin 1 and arginase-1 and their performance in early diagnosis of HCC. The incidence of HepPar-1 and Arg-1 were evaluated by IHC in 121 patients (HBV, HCC, HBV + HCC) and 30 healthy subjects.

Results

Arg-1 had significantly increased sensitivity in identification of HBV + HCC patients compared to HepPar-1 (P < 0.001). The sensitivity of arginase-1 is 96.3% whereas, the sensitivity of HepPar-1 is 72.7%. Arg-1 had higher specificity in identification of HBV + HCC patients compared to HepPar-1 (P < 0.05). With one positive marker, the sensitivity, the specificity and the positive predictive values and negative predictive value were 84.3%, 82.4%, 88.6% and 85.4% respectively. Also with one positive marker, the sensitivity and negative predictive value were significantly higher compared to the both 2 positive combinations. It was concluded that Arg-1 can improves the ability to detect HBV + HCC patients when compared with HepPar-1. When, both markers being positive, the specificity and PPVs of this combination were fairly higher. Concurrent use of these two proteins may be one of the best HCC detection patterns in needle specimens.

A case of primary clear cell hepatocellular carcinoma comprised mostly of clear cells

Clear cell hepatocellular carcinoma (CHCC) is defined as a tumor which contains more than 50% of clear cells. However, CHCC with more than 90% of clear cells are extremely rare. We report a case of a 65-year-old woman who was found to have a solitary mass, which was histologically diagnosed as clear cell hepatocellular carcinoma composed of 90% or more clear cells. The tumor presented rim arterial phase hyperenhancement in computed tomography, magnetic resonance imaging, and computed tomography during hepatic arteriography, and was classified as LR-M category according to The Liver Imaging Reporting and Data System version 2018(LI-RADS v2018). This tumor may mimic other tumors with similar radiographic features, such as intrahepatic cholangiocellular carcinoma and metastatic tumor.

Update on hepatocellular carcinoma: Pathologists’ review

Histopathologic diversity and several distinct histologic subtypes of hepatocellular carcinoma (HCC) are well-recognized. Recent advances in molecular pathology and growing knowledge about the biology associated with distinct histologic features and immuno-profile in HCC allowed pathologists to update classifications. Improving sub-classification will allow for more clinically relevant diagnoses and may allow for stratification into biologically meaningful subgroups. Therefore, immuno-histochemical and molecular testing are not only diagnostically useful, but also are being incorporated as crucial components in predicting prognosis of the patients with HCC. Possibilities of targeted therapy are being explored in HCC, and it will be important for pathologists to provide any data that may be valuable from a theranostic perspective. Herein, we review and provide updates regarding the pathologic sub-classification of HCC. Pathologic diagnostic approach and the role of biomarkers as prognosticators are reviewed. Further, the histopathology of four particular subtypes of HCC: Steatohepatitic, clear cell, fibrolamellar and scirrhous - and their clinical relevance, and the recent consensus on combined HCC-cholangiocarcinoma is summarized. Finally, emerging novel biomarkers and new approaches to HCC stratification are reviewed.

Clinicopathological features and surgical outcomes of four rare subtypes of primary liver carcinoma

OBJECTIVE

This study aimed to analyze clinicopathological and prognostic features of four rare pathological subtypes of primary liver malignancies to make better understanding of their clinical features.

METHODS

The clinicopathological data of 114 patients who were diagnosed with histologically proven four subtypes: clear cell carcinoma (CCC), giant cell carcinoma (GCC), sarcomatoid carcinoma (SC), and combined hepatocellular-cholangiocarcinoma (CHC) between October 1998 and August 2015 were reviewed. Their survival data were compared with those of 908 patients with histologically proven common hepatocellular carcinoma (HCC) (early- and advanced-stage HCC) during the same period.

RESULTS

The outcome of the CCC group was better than that of the other three subgroups, and was similar to that of the early-stage HCC group. Also, the smallest tumor size and the highest incidence of pseudocapsule formation were observed in the CCC group. The SC group had the worst outcome among these four subgroups; the prognosis was much poorer than that of any other subgroups, even poorer than that of the advanced-stage common HCC group. No statistical difference was observed between the GCC, CHC and advanced-stage HCC groups on survival analysis. The incidences of tumor vascular emboli, TNM staging and non-radical resection were three risk factors of the prognosis.

CONCLUSIONS

CCC is a low-degree malignancy and relatively favorably prognostic subtype of HCC. However, GCC, SC, and CHC are three rare high-degree malignancy subtypes of HCC with poor prognosis.

Clear cell hepatocellular carcinoma: origin, metabolic traits and fate of glycogenotic clear and ground glass cells

Clear cell hepatocellular carcinoma (CCHCC) has hitherto been considered an uncommon, highly differentiated variant of hepatocellular carcinoma (HCC) with a relatively favorable prognosis. CCHCC is composed of mixtures of clear and/or acidophilic ground glass hepatocytes with excessive glycogen and/or fat and shares histology, clinical features and etiology with common HCCs. Studies in animal models of chemical, hormonal and viral hepatocarcinogenesis and observations in patients with chronic liver diseases prone to develop HCC have shown that the majority of HCCs are preceded by, or associated with, focal or diffuse excessive storage of glycogen (glycogenosis) which later may be replaced by fat (lipidosis/steatosis). In ground glass cells, the glycogenosis is accompanied by proliferation of the smooth endoplasmic reticulum, which is closely related to glycogen particles and frequently harbors the hepatitis B surface antigen (HBsAg). From the findings in animal models a sequence of changes has been established, commencing with preneoplastic glycogenotic liver lesions, often containing ground glass cells, and progressing to glycogen-poor neoplasms via various intermediate stages, including glycogenotic/lipidotic clear cell foci, clear cell hepatocellular adenomas (CCHCA) rich in glycogen and/or fat, and CCHCC. A similar process seems to take place in humans, with clear cells frequently persisting in CCHCC and steatohepatitic HCC, which presumably represent intermediate stages in the development rather than particular variants of HCC. During the progression of the preneoplastic lesions, the clear and ground glass cells transform into cells characteristic of common HCC. The sequential cellular changes are associated with metabolic aberrations, which start with an activation of the insulin signaling cascade resulting in pre-neoplastic hepatic glycogenosis. The molecular and metabolic changes underlying the glycogenosis/lipidosis are apparently responsible for the dramatic metabolic shift from gluconeogenesis to the pentose phosphate pathway and Warburg-type glycolysis, which provide precursors and energy for an ever increasing cell proliferation during progression.

Morphologic Subtypes of Hepatocellular Carcinoma

Hepatocellular carcinomas can be further divided into distinct subtypes that provide important clinical information and biological insights. These subtypes are distinct from growth patterns and are on based on morphologic and molecular findings. There are 12 reasonably well-defined subtypes as well as 6 provisional subtypes, together making up 35% of all hepatocellular carcinomas. These subtypes are discussed, with an emphasis on their definitions and the key morphologic findings.

Immunohistochemical approach for the diagnosis of a liver mass on small biopsy specimens

Well-differentiated hepatocellular carcinoma (HCC) shares overlapping histological features with benign hepatocellular lesions, including hepatocellular adenoma and focal nodular hyperplasia in non-cirrhotic liver, and with high-grade dysplastic nodule in cirrhotic liver. Several metastatic tumors, such as neuroendocrine tumor, renal cell carcinoma, adrenocortical carcinoma, melanoma, and epithelioid angiomyolipoma, can be indistinguishable from HCC on histologic grounds. Since this distinction has important therapeutic implications, judicious use of immunohistochemical markers plays an important role in establishing an accurate diagnosis, especially when limited material of tumor is available on cell block or a small core biopsy. This review describes commonly used immunohistochemical markers used in the diagnosis of HCC, highlighting advantages and disadvantages of each marker, and suggests appropriate immunohistochemical panels for specific clinicopathologic situations.

Tissue- and Serum-Associated Biomarkers of Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC), one of the leading causes of cancer deaths in the world, is offering a challenge to human beings, with the current modes of treatment being a palliative approach. Lack of proper curative or preventive treatment methods encouraged extensive research around the world with an aim to detect a vaccine or therapeutic target biomolecule that could lead to development of a drug or vaccine against HCC. Biomarkers or biological disease markers have emerged as a potential tool as drug/vaccine targets, as they can accurately diagnose, predict, and even prevent the diseases. Biomarker expression in tissue, serum, plasma, or urine can detect tumor in very early stages of its development and monitor the cancer progression and also the effect of therapeutic interventions. Biomarker discoveries are driven by advanced techniques, such as proteomics, transcriptomics, whole genome sequencing, micro- and micro-RNA arrays, and translational clinics. In this review, an overview of the potential of tissue- and serum-associated HCC biomarkers as diagnostic, prognostic, and therapeutic targets for drug development is presented. In addition, we highlight recently developed micro-RNA, long noncoding RNA biomarkers, and single-nucleotide changes, which may be used independently or as complementary biomarkers. These active investigations going on around the world aimed at conquering HCC might show a bright light in the near future.

Hepatocellular Carcinoma: Histologic Subtypes

This review discusses the various histologic subtypes of hepatocellular carcinoma (HCC), focusing on their clinical features, pathologic features, immunohistochemical profiles, differential diagnosis, prognosis, and clinical relevance of diagnosis. The WHO recognized variants of scirrhous HCC, fibrolamellar carcinoma, combined HCC-cholangiocarcinoma (HCC-CC), sarcomatoid HCC, undifferentiated carcinoma, and lymphoepithelioma-like HCC are discussed in detail. Other subtypes including clear cell HCC, diffuse cirrhosis-like HCC, steatohepatitic HCC, transitional liver cell tumor, and CAP carcinoma are also reviewed.

Pathologic Features of Primary and Metastatic Hepatic Malignancies

In the mammalian liver, 60 % of the cellular components are hepatocytes while the remainder (35 %) includes biliary epithelium, Kupffer cells, endothelial cells, fat storing cells and connective tissue cells. Although neoplasms of hepatocytes are the most common, a significant number of both benign and malignant primary liver neoplasms arising from other cell types can develop, such as tumors of bile duct epithelium (Table 1). In addition, the liver is one of the most susceptible sites for metastatic tumors arising from other organs of the body. Not too long ago, liver tumors were left untreated because the liver was considered a complex and mysterious organ inaccessible to surgery. Advances in imaging procedures and surgical techniques over the past 40 years have revolutionized the approaches to the treatment of benign and malignant liver tumors. Subsegmentectomy, segmentectomy, lobectomy, and transplantation are routinely performed for the treatment of primary and metastatic liver tumors with minimal morbidity and mortality. Since accurate diagnosis remains the key to clinical and surgical management, the emphasis of this chapter is on classification, morphological features and differential diagnosis of malignant neoplasms of the liver.

Very late recurrence of Diethylstilbestrol - related clear cell carcinoma of the cervix: case report

Clear cell adenocarcinoma of the cervix is a rare tumor of the lower genital tract. It has been described in young women with a history of intra uterine exposure to diethylstilbestrol. This tumor is characterized by a greater tendency for late recurrences. In this article, we report the case of one exposed-patient who developed recurrence as liver metastases, 24 years after the initial treatment. This case demonstrates the need and the importance for continued follow-up in individuals prenatally exposed to diethylstilbestrol.

Arginase-1 is a novel immunohistochemical marker of hepatocellular differentiation

Arginase-1 is an enzyme that catalyzes the hydrolysis of arginine to ornithine and urea in the urea cycle. In normal tissues, arginase-1 is primarily expressed in hepatocytes. Recent investigations have reported that the vast majority of hepatocellular carcinomas express this marker, but it is found only rarely in nonhepatocellular tumors. Owing to its restricted expression in hepatocellular carcinomas, arginase-1 has proved to be a useful immunohistochemical marker for assisting in distinguishing between these tumors and other neoplasms with which they may be confused.

Multi-slice computed tomography manifestations of hepatic epithelioid angiomyolipoma

AIM: To explore the characteristics of multi-slice computed tomography (CT) manifestations of hepatic epithelioid angiomyolipoma (HEA), improve the rate of accurate diagnosis, and reduce the misdiagnostic rate.

METHODS: The multi-slice CT manifestations in five patients who were diagnosed with HEA definitely by postoperative pathological examination were analysed retrospectively. Three female patients and two male patients were included. Before operation, four patients received plain CT scanning and dynamic enhancement scanning, and the other patient only received enhancement scanning, with immunohistochemical analysis conducted after postoperative pathological examination. Four patients were misdiagnosed by CT, including three patients misdiagnosed with hepatic cell carcinoma and one patient with focal nodular hyperplasia.

RESULTS: Upper abdominal multi-slice spiral CT scanning and three-stage enhancement scanning were conducted in five patients with HEA before operation. HEA had certain characteristic CT manifestations: low density masses, a few relatively high-density masses or fat-density masses diffusely shown in foci, clear boundary, round or oval and large focus, and tumour size ranging from 3.1 cm × 2.5 cm to 7.0 cm × 5.2 cm. During enhancement scanning, the foci were significantly enhanced uniformly or non-uniformly during the arterial phase, while during the venous and equilibrium phases, the foci were enhanced continuously or showed obvious low-density masses. Obviously enhanced and widened vessels could be found adjacent to foci or in the central area of foci during the arterial phase.

CONCLUSION: CT manifestations of HEA have certain characteristics. Primary diagnosis can be obtained by combining CT findings with clinical data, but pathological examination is still needed for a definite diagnosis.

CT findings of primary clear cell carcinoma of liver: with analysis of 19 cases and review of the literature

PURPOSE

To analyze CT characteristics of primary clear cell carcinoma of the liver (PCCCL) and improve the current understanding and diagnose accuracy of the tumor.

METHODS

Pre- and post-contrast CT images of 19 patients with pathology proven PCCCL were retrospectively analyzed. The clinical data and CT findings as well as relevant literature reports were reviewed.

RESULTS

Thirteen patients were tested positive for HBsAg, and two patients were positive for HCVAb. The serum alpha-fetoprotein (AFP) levels of most tumors (14/19) were ≤20 ng/ml with 14 cases were associated with liver cirrhosis. All lesions were solitary intraparenchymal mass lesions which have well-defined boarders. On pre-contrast CT scans, 15 lesions appeared as hypo-attenuation and four lesions appeared as isointensity to the adjacent liver parenchyma. On post-contrast CT scans, 16 lesions showed avid enhancement on the hepatic arterial phase, of which 6 lesions were hypo-attenuation, and 10 lesions remained slightly hyper-attenuation or iso-attenuation on the portal venous phase images. Three lesions showed only mild enhancement on the hepatic arterial phase and hypo-attenuation on the portal venous phase. All lesions demonstrated hypointensity on the equilibrium phase. There are 12 lesions showed pseudocapsules. None of patients showed signs of portal vein thrombosis. There was no distal metastasis except only one patient had lymph node metastasis.

CONCLUSION

The characteristics of CT imaging of PCCCL, such as tend to form pseudocapsules and less involved with vascular invasion, could be useful in differentiating from common type hepatocellular carcinoma (CHCC). Some CT imaging characteristics of PCCCL are similar to CHCC, such as prone to occur in patients with liver cirrhosis and early enhancement pattern on the hepatic arterial phase as well as hypo-attenuation on the equilibrium phase. Those features could be useful in differentiating PCCCL from other liver tumors, such as hemangioma and hepatic metastases.

Octreotide and celecoxib synergistically encapsulate VX2 hepatic allografts following transcatheter arterial embolisation

To evaluate the encapsulation of VX2 hepatic allografts in rabbits induced by octreotide and celecoxib administration following transcatheter arterial embolisation (TAE), rabbits with hepatic VX2 allografts were divided into four groups: control, TAE, octreotide + celecoxib (O+C) and the multimodality therapy (TAE+O+C). Allograft metastasis, capsule thickness and percentage of clear cells were measured and vascular endothelial growth factor (VEGF) and CD31 were detected by immunohistochemistry and reverse transcription-polymerase chain reaction (RT-PCR) analysis. The extrahepatic metastases of each intervention group were significantly fewer than those of the control group, with the TAE+O+C group exhibiting the fewest extrahepatic metastases. The TAE+O+C group had the greatest proportion of clear cells and thickest capsule on day 30. Increased capsule thickness was negatively correlated with tumour metastasis. In addition, VEGF expression levels assessed by immunohistochemistry and RT-PCR in the three intervention groups were significantly lower than those in the control group. Furthermore, the TAE+O+C group had a significantly reduced CD31 count induced by TAE. These results demonstrate that TAE, followed by long-term administration of octreotide and celecoxib, synergistically inhibits VX2 hepatic allograft metastasis by increasing the proportion of clear cells, promoting encapsulation and inhibiting angiogenesis.

Therapeutic effect of coenzyme Q10 against experimentally-induced hepatocellular carcinoma in rats

The therapeutic potential of coenzyme Q10 was investigated in rats with hepatocellular carcinoma induced by trichloroacetic acid (0.5g/kg/day, p.o., for five days). Coenzyme Q10 treatment (0.4mg/kg/day, i.p.) was applied for four weeks following trichloroacetic acid administration. Coenzyme Q10 significantly suppressed lipid peroxidation, prevented the depletion of reduced glutathione and superoxide dismutase activity, and decreased the elevations of tumor necrosis factor-α and nitric oxide in liver tissue of rats with hepatocellular carcinoma. Also, the histopathological dysplastic changes induced by trichloroacetic acid in liver tissue were ameliorated by coenzyme Q10. Immunohistochemical analysis revealed that coenzyme Q10 significantly decreased the expression of hepPar-1, alpha-fetoprotein, inducible nitric oxide synthase, cyclooxygenase-2 and nuclear factor-κB in liver tissue of rats with hepatocellular carcinoma. It was concluded that coenzyme Q10 may represent a potential therapeutic option for liver carcinogenesis.

Arginase-1, HepPar-1, and Glypican-3 are the most effective panel of markers in distinguishing hepatocellular carcinoma from metastatic tumor on fine-needle aspiration specimens

Distinction of liver metastases from hepatocellular carcinoma (HCC) may present a diagnostic challenge. Arginase-1 (Arg-1) is a marker for HCC recently described in some literature. Immunohistochemical evaluation of Arg-1, hepatocyte paraffin-1 (HepPar-1), and glypican-3 expression was performed on 1,240 surgical specimens and 62 liver fine-needle aspiration specimens (29 HCCs, 28 metastatic tumors, and 5 benign liver cases). The staining results on tissue microarray sections showed that 2.7% and 3.1% of nonhepatic tumor cases were positive for HepPar-1 and glypican-3, respectively; none was positive for Arg-1. For fine-needle aspiration specimens, 19 HCCs were positive for all 3 markers; 9 were positive for 1 or 2 markers; and only 1 case was negative for all 3 markers. These data demonstrate that Arg-1 is the most specific marker in differentiating a non-HCC from HCC. It is recommended to use 3 markers as a panel in distinguishing HCC from metastatic carcinoma.

Retrospective study of cytologic features of well-differentiated hepatocellular carcinoma in dogs

BACKGROUND

Cytologic diagnosis of hepatocellular carcinoma is possible when hepatocytes have prominent criteria of malignancy, but is problematic when hepatocytes have a relatively normal morphologic appearance.

OBJECTIVES

The aim of this study was to determine the cytologic features of histologically confirmed well-differentiated hepatocellular carcinomas (WD-HCC) in dogs to develop reasonable criteria for an accurate diagnosis when obvious criteria of malignancy in hepatocytes are lacking.

METHODS

Slides of ultrasound-guided fine-needle aspirates of 15 histologically confirmed WD-HCC in dogs were evaluated retrospectively using a scoring system (0-3) established for 33 cytologic features. For comparison, 15 cytologic samples of non-nodular non-neoplastic liver were evaluated using the same criteria. Statistical analysis included multiple hypothesis testing using the Benjamini-Hochberg method or false discovery rate control to correct for multiple comparisons.

RESULTS

The most significant and useful cytologic features in the diagnosis of canine WD-HCC were dissociation of hepatocytes, acinar or palisading arrangements of neoplastic cells, and the presence of naked nuclei and capillaries, together with mild anisocytosis, anisokaryosis, multinuclearity, and increased N:C ratios.

CONCLUSIONS

Cytologic features of canine WD-HCC were determined. Further studies are warranted to compare these cytologic criteria among WD-HCC, hepatomas, and hyperplastic nodules and to examine co-variance of the 33 cytologic features.

A case of primary clear cell hepatocellular carcinoma in a non-cirrhotic liver: an immunohistochemical and ultrastructural study

The clear cell variant of hepatocellular carcinoma is a rare entity, occurring at a frequency of less than 10% of hepatocellular carcinoma, with a female prevalence and usually associated with hepatitis C and cirrhosis. We reported a case of primary clear cell hepatocellular carcinoma occurring in a non-cirrhotic liver without history of hepatitis. Our examination included gross pathology, histopathology, immunohistochemistry, special stains, and electron microscopy evaluation. The tumor was composed of sheets of medium-to-large cells with foamy and reticulated cytoplasm and small-to-medium sized nuclei with variably prominent nucleoli. Oil red O stain showed abundant intracellular lipid. Periodic Acid-Schiff stain confirmed the presence of abundant glycogen deposition. Immunohistochemically the tumor cells were positive for Hep Par1, negative for epithelial membrane antigen, steroidogenic factor-1, HMB45, melan A, CK7 and CK20. Electron microscopy study was performed, which was first done in a clear cell hepatocellular carcinoma occurring in a non-cirrhotic liver without elevation of liver function tests. Ultrastructural evaluation of the clear cells showed scarce cellular organelles, cytoplasmic lipid vacuoles and swollen mitochondria.

Expression of nestin, mesothelin and epithelial membrane antigen (EMA) in developing and adult human meninges and meningiomas

The spatial and temporal pattern of appearance of nestin, epithelial membrane antigen (EMA) and mesothelin proteins was immunohistochemically determined in the cells of normal developing and adult human meninges and meningiomas. Human meninges developed as two mesenchymal condensations in the head region. The simple squamous epithelium on the surface of leptomeninges developed during mesenchymal to epithelial transformation. Nestin appeared for the first time in week 7, EMA in week 8, while mesothelin appeared in week 22 of development. In the late fetal period and after birth, nestin expression decreased, whereas expression of EMA and mesothelin increased. EMA appeared in all surface epithelial cells and nodules, while mesothelin was found only in some of them. In adult meninges, all three proteins were predominantly localized in the surface epithelium and meningeal nodules. In meningothelial meningiomas (WHO grade I), EMA was detected in all tumor cells except in the endothelial cells, mesothelin characterized nests of tumor cells, while nestin was found predominantly in the walls of blood vessels. The distribution pattern of those proteins in normal meningeal and tumor cells indicates that nestin might characterize immature cells, while EMA and mesothelin appeared in maturing epithelial cells. Neoplastic transformation of these specific cell lineages contributes to the cell population in meningiomas.

Primary clear cell carcinoma in the liver: CT and MRI findings

AIM: To retrospectively analyze the computed tomography (CT) and magnetic resonance imaging (MRI) appearances of primary clear cell carcinoma of the liver (PCCCL) and compare the imaging appearances of PCCCL and common type hepatocellular carcinoma (CHCC) to determine whether any differences exist between the two groups.

METHODS: Twenty cases with pathologically proven PCCCL and 127 cases with CHCC in the Second Affiliated Hospital of Sun Yat-sen University were included in this study. CT or MRI images from these patients were retrospectively analyzed. The following imaging findings were reviewed: the presence of liver cirrhosis, tumor size, the enhancement pattern on dynamic contrast scanning, the presence of pseudo capsules, tumor rupture, portal vein thrombosis and lymph node metastasis.

RESULTS: Both PCCCL and CHCC were prone to occur in patients with liver cirrhosis, the association rate of liver cirrhosis was 80.0% and 78.7%, respectively (P > 0.05). The mean sizes of PCCCL and CHCC tumors were (7.28 ± 4.25) cm and (6.96 ± 3.98) cm, respectively. Small HCCs were found in 25.0% (5/20) of PCCCL and 19.7% (25/127) of CHCC cases. No significant differences in mean size and ratio of small HCCs were found between the two groups (P = 0.658 and 0.803, respectively). Compared with CHCC patients, PCCCL patients were more prone to form pseudo capsules (49.6% vs 75.0%, P = 0.034). Tumor rupture, typical HCC enhancement patterns and portal vein tumor thrombosis were detected in 15.0% (3/20), 72.2% (13/18) and 20.0% (4/20) of patients with PCCCL and 3.1% (4/127), 83.6% (97/116) and 17.3% (22/127) of patients with CHCC, respectively. There were no significant differences between the two groups (all P > 0.05). No patients with PCCCL and 2.4% (3/127) of patients with CHCC showed signs of lymph node metastasis (P > 0.05).

CONCLUSION: The imaging characteristics of PCCCL are similar to those of CHCC and could be useful for differentiating these from other liver tumors (such as hemangioma and hepatic metastases). PCCCLs are more prone than CHCCs to form pseudo capsules.

Arginase-1: a new immunohistochemical marker of hepatocytes and hepatocellular neoplasms

The distinction of hepatocellular carcinoma (HCC) from metastatic tumor in the liver often presents a diagnostic challenge that carries significant impact on prognostication and therapy. The number of diagnostically useful immunohistochemical markers of hepatocytes is limited to hepatocyte paraffin antigen (HepPar-1), polyclonal carcinoembryonic antigen, and CD10, with alpha-fetoprotein and glypican-3 labeling HCCs. Arginase-1 (Arg-1) is a binuclear manganese metalloenzyme that catalyzes the hydrolysis of arginine to ornithine and urea. We used immunohistochemistry to compare the sensitivity of Arg-1 to that of HepPar-1 in 151 HCCs. We found that the overall sensitivities of Arg-1 and HepPar-1 are 96.0% and 84.1%, respectively. The sensitivities of Arg-1 in well, moderately, and poorly differentiated HCCs are 100%, 96.2%, and 85.7%, respectively, whereas, in comparison, HepPar-1 demonstrated sensitivities of 100%, 83.0%, and 46.4% for well, moderately, and poorly differentiated tumors, respectively. There were no HCCs in our study that were reactive for HepPar-1 but nonreactive for Arg-1. We also examined Arg-1 expression in nonhepatocellular tumors, including many that are potential mimics of HCC (renal cell carcinomas, neuroendocrine tumors, melanomas, gastric adenocarcinomas, and adrenocortical carcinomas) and found that only 2 non-HCC tumors were reactive for Arg-1. Arg-1 represents a sensitive and specific marker of benign and malignant hepatocytes that may ultimately prove to be a useful diagnostic tool in routine surgical pathology practice.

Hepatocellular carcinoma with foamy histiocyte-like appearance: a deceptively clear cell carcinoma appearing variant

Hepatocellular carcinoma (HCC) shows many pathological features, and it varies architecturally and cytologically. There have been many reports and discussions of the morphological features of HCC. A 63-year-old man was found to have a solitary tumor in liver segment 7 that was diagnosed as HCC. A partial resection of liver segment 7 was performed. Microscopically, the tumor lesion showed a moderately differentiated HCC. There was also a lesion with foamy histiocyte-like cells corresponding to the white lesion in the face of the cut tumor. Immunohistochemical staining showed that they were negative for CD68, S-100, vimentin, and HMB-45. The cytoplasm itself was negative on periodic acid Schiff (PAS) and Sudan staining. Without immunohistological analysis, it is difficult to distinguish this HCC variant from clear cell carcinoma or metastases of renal cell carcinoma. It is important to recognize this type as a specific cytological variant of HCC that requires confirmation by immunohistochemistry. This report describes the case of a patient with a morphologically distinctive pattern of HCC with prominent cell cytoplasm that had a foamy histiocyte-like appearance. To the best of our knowledge, this is the first report of this HCC variant.

Urinary biomarkers for the early diagnosis of kidney cancer

OBJECTIVE

To test the hypothesis that increased tumor expression of proteins such as aquaporin-1 (AQP1) and adipophilin (ADFP) in patients with renal cancer would result in increased urine AQP1 and ADFP excretion.

PATIENTS AND METHODS

Prenephrectomy and postnephrectomy (pseudocontrol) urine samples were collected from 42 patients with an incidental radiographically discovered renal mass and presurgical presumptive diagnosis of kidney cancer from July 8, 2008, through March 10, 2009. Also enrolled were 15 control patients who underwent nonrenal surgery and 19 healthy volunteers. Urine AQP1 and ADFP concentrations normalized to urine creatinine were determined by sensitive and specific Western blot assays.

RESULTS

Mean +/- SD preexcision urine AQP1 and ADFP concentrations (76+/-29 and 117+/-74 arbitrary units, respectively) in patients with a pathologic diagnosis of clear cell (n=22) or papillary (n=10) cancer were significantly greater than in patients with renal cancer of nonproximal tubule origin, control surgical patients, and healthy volunteers (combined values of 0.1+/-0.1 and 1.0+/-1.6 arbitrary units, respectively; n=44; P<.001). The AQP1 and ADFP concentrations decreased 88% to 97% in the 25 patients with clear cell or papillary cancer who provided postnephrectomy follow-up urine samples. In patients with clear cell and papillary carcinoma, a linear correlation (Spearman) was found between tumor size and preexcision urine AQP1 or ADFP concentration (r=0.82 and 0.76, respectively; P<.001 for each).

CONCLUSION

Urine AQP1 and ADFP concentrations appear to be sensitive and specific biomarkers of kidney cancers of proximal tubule origin. These biomarkers may be useful to diagnose an imaged renal mass and screen for kidney cancer at an early stage.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00851994.

The best immunohistochemical panel for differentiating hepatocellular carcinoma from metastatic adenocarcinoma

It can be difficult to differentiate hepatocellular carcinoma (HCC) from metastatic adenocarcinoma (MA). An appropriate immunohistochemical panel is required for the differential diagnosis. This study aimed at finding the best panel, including hepatocyte-specific antigen (Hepatocyte), pCEA, CD10, Villin, CD34, TTF-1, MOC-31, CK7, and CK20 antibodies. Sixty-eight cases of HCC and 107 cases of MA were investigated. Hepatocyte positivity was seen in 95.6% of HCCs and in 1.9% of MAs. pCEA was expressed in 47.8% of HCCs and in 86.8% of MAs. CD10 stained 73.13% of HCCs and 36.9% of MAs. Villin was positive in 23.5% of HCCs and in 81.0% of MAs. Canalicular staining with pCEA, CD10, and Villin was seen only in HCCs. Sinusoidal CD34 staining was seen only in 42.6% of HCCs. A small subset of HCCs demonstrated cytoplasmic TTF-1 and MOC-31. CK7 was expressed in 29.4% of HCCs and in 29.9% of MAs, whereas CK20 stained 14.7% of HCCs and 62.6% of MAs. In conclusion, Hepatocyte should be combined with pCEA, MOC-31, CD10, and CD34. Canalicular staining with pCEA, CD10, and Villin is specific for HCC. CK7 and CK20 expression may be seen in some HCCs. We suggest that the best panel for discriminating HCC from MA should contain Hepatocyte, MOC-31, pCEA, CD10, and CD34.

Therapy and prognostic features of primary clear cell carcinoma of the liver

AIM: To clarify the therapeutic strategies and prognosis factors of primary clear cell carcinoma of the liver (PCCCL).

METHODS: The clinical pathological data of 64 patients with PCCCL treated with hepatectomy in our hospital from January 2000 to January 2006 were analyzed retrospectively. The patients were divided into two groups to make treatment analysis: curative resection only (n = 40); and curative resection and postoperative chemotherapy with calcium folinate and tegafur (n = 24). Meanwhile, the PCCCL patients were subdivided into two subgroups on the basis of the proportion of clear cells in the tumor for pathological analysis. There were 36 cases in subgroup A for which the proportion of clear cells was more than 70%, and 28 cases in subgroup B for which the proportion was less or equal to 70%, comparing analysis of median survival time of the counterpart groups. Univariate and multivariate analyses were performed to examine factors that affected clinical prognosis, recurrence and metastasis.

RESULTS: Median survival period of the curative surgery group was 38 mo, while the counterpart was 41 mo. Median survival period for group A was 41 mo, while group B was 19 mo. The Kaplan-Meier method showed that capsule formation, preoperative liver function, hepatitis C virus infection, large vascular invasion and multiple tumor occurrences were related to disease-free survival. Cox regression analysis showed that the clear cell ratio, capsule formation, preoperative liver function and large vascular invasion were independent risk factors for overall survival.

CONCLUSION: Postoperative chemotherapy has no obvious effect on survival of patients with PCCCL. Clear cell ratio, capsule formation, preoperative liver function, and vascular invasion were independent risk factors for prognosis.

Surveillance and diagnosis of hepatocellular carcinoma in patients with cirrhosis

Early identification of hepatocellular carcinoma (HCC) is more frequent because of surveillance programs for HCC worldwide. The optimal strategy of surveillance in cirrhosis is a current topical issue. In terms of diagnosis, recent advances in non-invasive imaging technology, including various techniques of harmonic ultrasound, new ultrasound contrast agents, multi-slice helical computed tomography and rapid high quality magnetic resonance, have all improved the accuracy of diagnosis. Consequently the role of liver biopsy in diagnosis of HCC has declined. The imaging diagnosis relies on the hallmark of arterial hypervascularity with portal venous washout. However, with recent advances in genomics and proteomics a great number of potential serum and tissue markers have been identified and are being developed as new candidate markers for both diagnosis and prognosis of hepatocellular carcinoma, and may increase the need for liver biopsy.

Hepatocyte Paraffin 1 Immunoreactivity in Early Colon Carcinogenesis

Background

This study was aimed at evaluating the correlation between Hepatocyte paraffin 1 (Hep par 1) and colorectal cancer.

Methods

To this end, 50 intestinal biopsies were analyzed including 10 colorectal polyps with low grade dysplasia, 10 with high grade dysplasia, 10 colorectal adenocarcinomas, 10 specimens of normal ileum and 10 of normal colon mucosa. Tissue sections were immunostained for Hep par 1 utilizing a commercial antibody. Normal colonic mucosa did not express Hep par 1.

Results

Immunoreactivity for Hep par 1 was detected in 20% of polyps with low grade dysplasia, 50% of polyps with high grade dysplasia and 60% of colorectal carcinomas. Hep par 1 was frequently detected in the deepest areas of adenocarcinomas mainly in infiltrating tumour cells.

Conclusions

Our data show that Hep par 1 immunoreactivity in human colon carcinogenesis is correlated with progression from low grade to high grade dysplasia and adenocarcinoma. In clinical practice, our data show that caution should be taken in utilizing Hep par 1 as the sole tool in differentiating hepatocellular carcinoma from a liver metastasis of colon adenocarcinoma. Our data encourage further investigations into the potential role played by Hep par 1 in gastrointestinal carcinogenesis.

Synchronous renal cell carcinoma and clear cell hepatocellular carcinoma mimicking metastatic disease

Double carcinomas of hepatocellular and renal cell carcinoma (RCC) are extremely rare, and among the reported cases, none of the hepatocellular carcinomas show clear cell change. We report a case of synchronous double primary clear cell tumor in the liver and the kidney of a 70-year-old male. The renal mass was a renal cell carcinoma of mixed clear and granular cell types, and the hepatic mass was a hepatocellular carcinoma with extensive clear cell change that mimicked a metastatic renal cell carcinoma. A simple battery of immunohistochemical stains composed of hepatocyte antigen, and CD10 was performed to make a definite diagnosis.

Hepatic angiomyolipoma mimicking hepatic clear cell carcinoma

Angiomyolipoma usually involves the kidney and rarely affects the liver. This study reports a case of angiomyolipoma of the liver in a 47-year-old Chinese woman. The patient did not present with abdominal pain and jaundice. Imaging showed a small mass in the right liver. The hepatic artery and portal vein were free from invasion. Partial hepatectomy was performed after a tentative diagnosis of clear cell carcinoma of the liver by needle biopsy. Histopathological examination of the resected specimen revealed angiomyolipoma originating in the liver. The post-operative clinical course was uneventful and, at the time of writing, the patient was well with no signs of recurrence 6 months after operation. To our knowledge this is the first documented case of an angiomyolipoma arising in the liver mimicking hepatic clear cell carcinoma.

Application of Immunohistochemistry to the Genitourinary System (Prostate, Urinary Bladder, Testis, and Kidney)

Context.—The variety of morphologic patterns of different entities of the genitourinary tract can present a diagnostic dilemma for the pathologist. This is especially true in cases of mimics of cancer, a cancer of unknown primary, or poorly differentiated tumors, in which it is hard to assign histogenesis needed to plan the correct therapy for the patient. Immunohistochemistry offers a better capacity than hematoxylin-eosin staining alone to differentiate human tissue types. Also, in the past decades, several techniques had been developed to differentiate between benign and malignant processes with morphologic overlap. By using immunohistochemistry in selected cases, the rate of false-negative and false-positive diagnoses can be reduced, and some patients are afforded the opportunity to get more specific or effective therapy as a result.

Objective.—For each subgroup of genitourinary system tumors, common diagnostic problems are reviewed, and immunohistochemical markers useful in addressing these problems are discussed, along with expected patterns of immunoreactivity.

Data Sources.—The pertinent literature, with focus on immunohistochemical staining of tumors of the genitourinary tract.

Conclusions.—The addition of immunohistochemistry to the diagnostic armamentarium for genitourinary pathologic diagnosis has increased the sensitivity and specificity of diagnoses and aided in the selection of optional therapeutic regimens in selected cases.

Clinicopathological and prognostic features of primary clear cell carcinoma of the liver

AIM

Primary clear cell carcinoma of the liver (PCCCL) is a subgroup of primary hepatocellular carcinoma (HCC), pathologically characterized by diffuse clear cells of the tumor, showing a clear cytoplasm that does not stain with hematoxylin-eosin. At present, its clinicopathological and prognostic features are not fully clarified. This study aims to clarify the clinicopathological and prognostic features of PCCCL.

METHODS

The clinicopathological data of 43 patients with PCCCL treated with hepatectomy in our hospital from January 1999 to December 2003 were retrospectively analyzed.

RESULTS

The chi(2)-test showed a positive rate of hepatitis C virus (HCV) infection and capsule formation in the PCCCL group, which was markedly higher than in the common type HCC (CHCC) group (P = 0.000 and P = 0.005). Meanwhile, the vascular invasion rate was notably lower in the PCCCL group, but there were no significant differences between the twogroups (P = 0.129). The Kaplan-Meier method showed that the 1-, 3-, and 5-year survival rates were significantly higher in the PCCCL group than in the CHCC group (P = 0.021). The prognosis of patients in the PCCCL group was related to capsule formation, vascular invasion, liver cirrhosis, and clear cell ratio. The 1-, 3-, and 5-year survival rates were markedly higher in the group with a higher clear cell ratio than in the group with a lower clear cell ratio (P = 0.011).

CONCLUSION

The notable clinicopathological features of the patients in the PCCCL group included a higher rate of HCV infection, capsule formation, and a lower rate of vascular invasion. The prognosis was better than that of the patients in the CHCC group and related to the ratio of clear cells.

Case of clear-cell hepatocellular carcinoma that developed in the normal liver of a middle-aged woman

A 36-year-old woman was admitted to our department for close examination of a liver tumor that was found during a medical checkup. Abdominal US, CT and MRI showed a tumor in segment 7 (S7) of the liver. Although imaging suggested hepatocellular carcinoma, laboratory tests showed no abnormality in liver function, hepatitis virus markers were negative, and tumor markers including protein induced by vitamin K absence or antagonist II (PIVKA-II), α-fetoprotein (AFP), carbohydrate antigen 19-9 (CA19-9), and carcinoembryonic antigen (CEA) were all within normal ranges. Upon aspiration biopsy of the liver, the histopathological diagnosis was moderately differentiated hepatocellular carcinoma. Therefore, right hepatectomy was performed. Although a part of the tumor was necrotic, about 60% of the viable part showed a clear-cell variant. Consequently, it was diagnosed as clear-cell hepatocellular carcinoma. It was noted that the background liver tissue was normal. This case is worthy of reporting because development of clear-cell hepatocellular carcinoma in the normal liver of a middle-aged woman is rarely seen.

Best practices in diagnostic immunohistochemistry: hepatocellular carcinoma versus metastatic neoplasms

CONTEXT

Immunohistochemistry plays a crucial role in the diagnosis of hepatocellular carcinoma and in its distinction from other primary and metastatic neoplasms. Because limited tissue is available with fine-needle and core biopsies, appropriate selection of antibodies is imperative.

OBJECTIVE

To review the antibodies used for the diagnosis of hepatocellular carcinoma and to outline an immunohistochemical approach in commonly encountered clinical situations.

DATA SOURCES

Our experience and review of research articles published in the English literature between 1987 and 2006.

CONCLUSIONS

Hep Par 1 and polyclonal carcinoembryonic antigen are the most reliable markers for hepatocellular differentiation, but they have low sensitivity for poorly differentiated cases. Immunohistochemistry for glypican-3 shows promise for the diagnosis of poorly differentiated hepatocellular carcinoma and for its distinction from benign processes such as hepatic adenoma. Further studies with a large number of cases are required before it can be widely used. The combination of Hep Par 1 and MOC-31 will allow for the diagnosis of hepatocellular carcinoma in most cases and will guide the selection of immunohistochemical markers for further workup.