Intrahepatic cholangiocarcinoma with lymphoepithelioma-like component

Epstein-Bar Virus-Positive Lymphoepithelioma-Like Intrahepatic Cholangiocarcinoma: A Case Report and Literature Review

Intrahepatic cholangiocarcinoma is a primary liver malignancy with poor prognosis and limited treatment options. Lymphoepithelioma-like intrahepatic cholangiocarcinoma is an exceedingly rare variant of intrahepatic cholangiocarcinoma that histologically resembles nasopharyngeal carcinoma, previously known as lymphoepithelioma. It was first reported by Hsu et al in 1996 and they were able to show the presence of Epstein-Barr virus in tumor cells. Even though several risk factors for the development of intrahepatic cholangiocarcinoma have been identified, the association between Epstein-Barr virus and intrahepatic cholangiocarcinoma is relatively rare. This article aims at discussing a female patient's lymphoepithelioma-like intrahepatic cholangiocarcinoma tumor and summarizing the existing literature on Epstein-Barr virus-positiveLymphoepithelioma-like intrahepatic cholangiocarcinoma, including the clinical features, pathogenesis, diagnostic challenges, treatment approaches, prognosis, and histopathologic description.

Comparison of the clinicoradiological features and outcomes of lymphoepithelioma-like cholangiocarcinoma and conventional intrahepatic cholangiocarcinoma: A propensity score matching analysis

BACKGROUND/PURPOSE

Lymphoepithelioma-like cholangiocarcinoma (LELCC) is a rare variant of intrahepatic cholangiocarcinoma (ICC). We aim to analyze the differences in the clinical and radiological features of LELCC and ICC.

METHODS

Between January 2003 and December 2019, a total of 21 patients diagnosed with LELCC were retrospectively enrolled, and 84 patients with ICC were selected through propensity score matching by sex, age, and initial cancer stage. The clinical characteristics, pathological findings, and radiological features were analyzed. The differences in overall survival (OS) between LELCC and ICC were evaluated using the Kaplan-Meier method.

RESULTS

The serum carbohydrate antigen 19-9 (CA 19-9) level was higher in the ICC group than in the LELCC group (77.9 vs 30.0 U/mL, p = 0.004). Non-rim arterial phase hyperenhancement (47.1% vs 13.7%, p = 0.005) and portovenous washout (35.3% vs 4.1%, p = 0.001) were more frequently observed in the LELCC group than in the ICC group. Intrahepatic duct dilatation was a distinct feature of the ICC group. The 5-year OS rates in the LELCC and ICC groups were 69.3% and 58.2%, respectively (p = 0.047). The 5-year OS of patients with stages I and II LELCC between ICC were not significantly different (90.0% vs 83.4%, p = 0.464). However, the 5-year OS of patients with stages III and IV LELCC was more favorable than that of patients with ICC (29.2% vs 23.0%, p = 0.017).

CONCLUSIONS

LELCC had a favorable outcome and several different clinicoradiological features compared with ICC.

Recent Advances in Pathology of Intrahepatic Cholangiocarcinoma

Intrahepatic cholangiocarcinoma (ICCA) is a malignant epithelial neoplasm characterized by biliary differentiation within the liver. ICCA is molecularly heterogeneous and exhibits a broad spectrum of histopathological features. It is a highly aggressive carcinoma with high mortality and poor survival rates. ICCAs are classified into two main subtypes: the small-duct type and large-duct types. These two tumor types have different cell origins and clinicopathological features. ICCAs are characterized by numerous molecular alterations, including mutations in KRAS, TP53, IDH1/2, ARID1A, BAP1, BRAF, SAMD4, and EGFR, and FGFR2 fusion. Two main molecular subtypes-inflammation and proliferation-have been proposed. Recent advances in high-throughput assays using next-generation sequencing have improved our understanding of ICCA pathogenesis and molecular genetics. The diagnosis of ICCA poses a significant challenge for pathologists because of its varied morphologies and phenotypes. Accurate diagnosis of ICCA is essential for effective patient management and prognostic determination. This article provides an updated overview of ICCA pathology, focusing particularly on molecular features, histological subtypes, and diagnostic approaches.

The MR Imaging of Primary Intrahepatic Lymphoepithelioma-like Cholangiocarcinoma: A Diagnostic Challenge

PURPOSE

To characterize the magnetic resonance imaging features of primary intrahepatic lymphoepithelioma-like cholangiocarcinoma (LELCC).

MATERIALS AND METHODS

Thirty-four patients with 38 histologically confirmed LELCCs were enrolled retrospectively from January 2014 to August 2022. We evaluated the clinical features, histologic findings, and imaging manifestations on dynamic enhanced MRI.

RESULTS

74% (25/34) of the cases were associated with EBV infection. Moreover, patients infected with EBV exhibited a lower level of Ki-67 proliferation. The serum CA199 level was elevated in 10 patients. The median tumor diameter was 2.8 cm (range, 1.1-8.7 cm). Most tumors were well-defined with a smooth or lobulated margin and showed peripheral hyperintensity and central hypointensity on T2-weighted imaging (T2WI). T2 hyperintense foci were recognized in 8 patients. In the dynamic enhanced MRI, 21 tumors demonstrated Type A enhancement pattern (rim enhancement), 10 demonstrated Type B (rapid wash-in and wash-out), and seven demonstrated Type C (rapid wash-in without wash-out). Capsular enhancement in PVP or DP was found in 22 tumors. A few patients had satellite lesions, portal vein thrombosis, bile duct dilatation, and distal metastasis. Lymph node metastases were discovered pathologically in 11 patients.

CONCLUSIONS

MRI findings of LELCC vary and are non-specific. While a majority of LELCCs exhibit typical features of intrahepatic cholangiocarcinoma (iCCA), unique findings like T2 hyperintense foci or capsular enhancement could suggest LELCC. EBV infection and elevated tumor markers can aid in differentiation. However, given the mimics of some cases of liver hypervascular lesions, histological examination remains essential for definitive diagnosis.

Lymphoepithelioma-like cholangiocarcinoma not associated with Epstein-Barr virus or hepatitis virus: case report and literature review of 100 reported cases

Lymphoepithelioma-like cholangiocarcinoma (LEL-CC) is a type of lymphoepithelioma-like carcinoma (LELC) and a rare variant of primary liver tumor. Although it is uncommon and only 100 cases have been reported thus far, the number of reports has increased in recent years. LEL-CC reportedly occurs more frequently in Asian women; Epstein-Barr virus (EBV) and hepatitis viruses are both strongly associated with tumor development. Here, we describe a 76-year-old woman who exhibited LEL-CC not associated with EBV or hepatitis virus. She was referred to our department with a 3.0-cm × 2.8-cm tumor in the left lobe of the liver. Based on computed tomography and magnetic resonance imaging findings, the tumor was preoperatively diagnosed as hepatocellular carcinoma. Thus, we performed extended left hepatectomy with caudal lobectomy. Histopathological examinations revealed columnar tumor cells with atypical nuclei that proliferated in a cord-like or glandular tubular pattern with dense lymphocytic infiltration. Immunohistochemical analysis showed negative HepPar-1 and arginase findings, indicating non-hepatocyte origin; however, the biliary-type cytokeratins CK7 and CK19 were detected. Based on these findings, the tumor was identified as LEL-CC. EBV-encoded RNA in situ hybridization findings were negative; the patient's clinical characteristics were not suggestive of hepatitis virus infection. In conclusion, we suggest that clinicians consider LEL-CC as a differential diagnosis for liver tumors in Asian women, including patients without EBV or hepatitis virus.

Epstein-Barr virus infection-associated cholangiocarcinoma: a report of one case and the review of literature

The clinical data of a patient with Epstein-barr virus (EBV) associated with cholangiocarcinoma was reported in this paper: a case of a 36-year-old female presented with abdominal pain and systemic skin yellowing combined with skin itching. Laboratory studies showed increase in alanine aminotransferase 242 U/L, aspartate aminotransferase 404 U/L, r-glutamyltransferase 1516 U/L, total bilirubin 308.2 µmol/L and CA199 (101.0 U/ml). AFP (4.5 ng/ml) was normal. CT revealed multiple space-occupying lesions in the liver. PET-CT revealed liver malignant tumor and lymph node metastasis. Liver puncture pathology revealed infiltrative growth of significant heterocyst nests in the liver tissue, which was morphologically consistent with malignant tumors, considering poorly differentiated carcinoma. Pathology suggestion: combining liver puncture with morphology, immunohistochemistry, and EBV in situ hybridization results, it was consistent with EB virus-associated poorly differentiated carcinoma, therefore, consider EBV infection-associated poorly differentiated cholangiocarcinoma (CCA) (LELC morphology). The patient underwent liver transplantation in Hangzhou Shulan Hospital on June 8, 2021 successfully. After surgery, the patient orally took tacrolimus for anti-rejection, entecavir for antiviral therapy, gemcitabine 1.2 g + cis-platinum 30 mg for chemotherapy. After following up for more than 5 months post liver transplantation, the condition of the patient deteriorated. The patient subsequently died. Based on the case of our patient and the review of existing literature, when the patient's serum CA199 increased, AFP did not change significantly, and there was no previous history of hepatitis B. CT revealed a low-density mass in the liver, ring enhancement in the arterial phase, and heterogeneous enhancement of the tumor in the delayed phase. Ring enhancement of the liver lesion mass was observed on MRI. Consider the might possibility of hepatic CCA. When patients showed recurrent tonsillitis at an early age, EBV virus infection should be vigilant and oropharyngeal tissue should persist, diagnosis of EBV-associated liver cancer should be considered. In particular, EBV infection-related liver cancer is relatively rare, the clinician should improve the recognition of the disease to strive for early diagnosis and therapy.

Lymphoepithelioma-like neoplasm of the biliary tract with 'probable low malignant potential'

AIMS

Lymphoepithelioma-like carcinomas (LELCs) are uncommon epithelial cancers characteristically showing two distinct components consisting of malignant epithelial cells and prominent dense lymphoid infiltrate. Hepatic LELCs consist of two types, the lymphoepithelioma-like hepatocellular carcinoma and lymphoepithelioma-like cholangiocarcinoma (LEL-CCA), with the latter being strongly associated with Epstein-Barr virus (EBV).

METHODS AND RESULTS

We present a series of three cases of intrahepatic biliary EBV-associated LEL tumours in which the biliary epithelial component showed a distinctly benign appearance, instead of the usual malignant epithelial features of a typical CCA or EBV-associated LEL-CCA. In the lesions, the biliary epithelium showed interconnecting glands or cords of cells. All had a very low proliferation (Ki-67) index. Immunohistochemistry for IDH1 and TP53 performed on two cases was negative and molecular tests for EGFR and KRAS gene mutations performed on one were negative. Prognosis was very good in all three cases, with patients alive with no evidence of disease 24-62 months after surgery. Intriguingly, all three cases had co-infection of HBV and EBV. These cases are also discussed in the context of the 63 cases of LEL-CCA available in the literature, with a focus on epidemiology, clinicopathological features and potential research interests.

CONCLUSIONS

Based on the distinct clinicopathological features and unique survival benefits, we believe these tumours represent the benign end of the spectrum of EBV-associated lymphoepithelial biliary carcinomas. Whether these tumours require a revision of the current nomenclature to 'lymphoepithelioma-like neoplasm of the biliary tract with probable low malignant potential' will require more detailed analysis with larger case-series.

Lymphoepithelioma-like Intrahepatic Cholangiocarcinoma Is a Distinct Entity With Frequent pTERT/TP53 Mutations and Comprises 2 Subgroups Based on Epstein-Barr Virus Infection

The molecular characteristics of lymphoepithelioma-like intrahepatic cholangiocarcinoma (LELCC) remain elusive. We examined 27 LELCC cases through next-generation sequencing using a panel of genes commonly mutated in primary liver cancers. Alterations in BAP1, ARID1A, ARID2, and PBRM1 were detected through immunohistochemistry. Fluorescence in situ hybridization was performed to analyze FGFR2 fusions and CCND1 amplification. LELCC is histologically classified as predominantly undifferentiated or glandular. Epstein-Barr virus-encoded small RNA (EBER) expression was found in 16 LELCCs. Approximately 50% of LELCCs expressed programmed death-ligand 1 strongly. Notably, recurrent pTERT and TP53 mutations were detected in 9 (38%) and 8 (33%) tumors, respectively. Only 2 LELCCs exhibited loss of expression for PBRM1. Alterations in genes typically involved in intrahepatic cholangiocarcinoma, including IDH1, IDH2, ARID1A, ARID2, and BAP1, and FGFR2 fusions, were not identified. The 2-step clustering analysis showed 2 distinct subgroups in LELCC, which were separated by EBER expression. A meta-analysis of all reported cases (n=85) has shown that EBER+ LELCC is strongly associated with the female sex, younger age, and exhibited predominantly glandular differentiation (P=0.001, 0.012, and <0.001, respectively). Patients with EBER- LELCC were more likely to have viral hepatitis and cirrhosis (P=0.003 and 0.005, respectively). Genetic analysis demonstrated that EBER- LELCC was significantly associated with pTERT and TP53 mutations (P=0.033 and 0.008, respectively). In conclusion, LELCC is genetically distinct from intrahepatic cholangiocarcinoma. EBER- LELCC may exhibit a different pathogenesis from EBER+ LELCC. High programmed death-ligand 1 expression in LELCC has implications for potential immunotherapeutic strategies.

Lymphoepithelioma-like cholangiocarcinoma with Epstein-Barr virus infection treated by radiofrequency ablation

Lymphoepithelioma-like cholangiocarcinoma (LELCC) is a rare intrahepatic tumor. There are usually no specific physical findings, and the tumors are often diagnosed incidentally and are frequently large-sized at diagnosis. The imaging findings of LELCC resemble those of hepatocellular carcinoma (HCC). Tumors are often found in large-sized and advanced at diagnosis, and the main treatment of the disease is surgical resection. Herein, we report treating a patient with early stage LELCC by radiofrequency ablation (RFA). We diagnosed this tumor in a 27-year-old Chinese female with a history of chronic hepatitis B (CHB). Based on the findings of blood examination, abdominal ultrasonography, and gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced magnetic resonance imaging (MRI), this tumor was diagnosed as suspected HCC. Ultrasound-guided percutaneous tumor biopsy and RFA were performed at the same time. The histopathological findings finally revealed the diagnosis of LELCC. To the best of our knowledge, this is the first report, in the English-language literature, of the treatment of LELCC by RFA; we suggest that RFA might be a candidate treatment for small-sized early stage LELCC.

Immune microenvironment of hepatocellular carcinoma, intrahepatic cholangiocarcinoma and liver metastasis of colorectal adenocarcinoma: Relationship with histopathological and molecular classifications

Tumor tissue is composed of tumor cells and tumor stroma. Tumor stroma contains various immune cells and non-immune stromal cells, forming a complex tumor microenvironment which plays pivotal roles in regulating tumor growth. Recent successes in immunotherapies against tumors, including immune checkpoint inhibitors, have further raised interests in the immune microenvironment of liver carcinoma. The immune microenvironment of tumors is formed because of interactions among tumor cells, immune cells and non-immune stromal cells, including fibroblasts and endothelial cells. Different patterns of immune microenvironment are observed among different tumor subtypes, and their clinicopathological significance and intertumor/intratumor heterogeneity are being intensively studied. Here, we review the immune microenvironment of hepatocellular carcinoma, intrahepatic cholangiocarcinoma and liver metastasis of colorectal adenocarcinoma, focusing on its histopathological appearance, clinicopathological significance, and relationship with histological and molecular classifications. Understanding the comprehensive histopathological picture of a tumor immune microenvironment, in addition to molecular and genetic approaches, will further potentiate the effort for precision medicine in the era of tumor-targeting immunotherapy.

The CT and MRI Features of Primary Intrahepatic Lymphoepithelioma-Like Cholangiocarcinoma

OBJECTIVE. The purpose of our study was to retrospectively characterize the CT and MRI features of primary intrahepatic lymphoepithelioma-like cholangiocarcinoma (LELCC). MATERIALS AND METHODS. Eleven patients (10 women and one man; age range, 30-63 years) with 11 pathologically proven LELCCs were enrolled retrospectively from April 2016 to December 2018. Triphasic enhanced images were obtained of all patients: MR images of five patients, CT images of five patients, and both CT and MR images of one patient. The clinical data and CT and MRI findings were reviewed. RESULTS. All LELCC cases were associated with Epstein-Barr virus (EBV) infection. Eight of the 11 patients had hepatitis B virus (HBV) infection. The tumor diameter ranged from 1.1 to 8.7 cm. All tumors were well defined with a smooth or lobulated margin. A cystic area was noted in two of the 11 tumors. After the administration of contrast material, the tumors showed homogeneous (n = 7) or heterogeneous (n = 4) hypervascular arterial enhancement and gradual washout, delayed central scar or irregular enhancement (n = 9), delayed circular thin or incomplete pseudocapsule enhancement (n = 7), and homogeneous hypointensity in the hepatobiliary phase (n = 2). No cirrhosis, focal dilatation of intrahepatic ducts, or satellite nodules were detected. Lymphadenopathy were detected in four patients, appearing as hypervascular enhancement and no necrosis (even in multiple nodes > 3 cm) or as moderate peripheral enhancement and necrosis. CONCLUSION. A liver mass in a middle-aged woman with EBV and HBV infection that appears on CT and MRI to have a well-defined boundary and a combination of hypervascularity, washout, delayed intratumoral enhancement, or pseudocapsule enhancement may suggest an imaging diagnosis of primary LELCC. More cases are needed to better understand this disease.

Lymphoepithelioma-like carcinoma in liver not associated with Epstein-Barr virus: a report of 3 cases and literature review

Background

Lymphoepithelioma-like carcinoma is a rare distinctive variant of liver cancer with unique epidemiological and pathological characteristics, characterized by dense lymphocyte infiltration. It can be divided into lymphoepithelioma-like hepatocellular carcinoma and lymphoepithelioma-like intrahepatic cholangiocarcinoma. Existing research shows that the prognosis of this tumor is good. To date, only 101 cases have been reported.

Case presentation

The first patient was a 62-year-old Chinese man with hepatitis B virus infection who presented with a single lesion in the liver. The patient underwent surgical treatment and was discharged on the 4th day. The patient was diagnosed with combined lymphoepithelioma-like hepatocellular carcinoma and cholangiocarcinoma; he has been alive for 15 months. The second patient was a 63-year-old Chinese woman with right upper abdominal pain and hepatitis B virus infection. The imaging examination revealed a single lesion in the liver. The patient underwent surgical treatment and was discharged 1 week later. The patient was diagnosed with lymphoepithelioma-like hepatocellular carcinoma and was considered to have recurrence in the lymph nodes approximately 2 years after the operation. The patient underwent local radiotherapy; she has been alive for 60 months. The third patient was a 50-year-old Chinese man with hepatitis B virus infection who presented with a single lesion in the liver and two enlarged lymph nodes. The patient received liver puncture before surgery to indicate lymph node metastasis and experienced local recurrence after liver resection. The patient underwent chemotherapy and radiotherapy. The patient was diagnosed with lymphoepithelioma-like hepatocellular carcinoma. The patient was deceased at 24-month follow-up.

Conclusions

This article reports 3 cases without Epstein-Barr virus and reviews the current literature, which suggests even mixed pathological type or locally advanced cases of LELC with lymph node metastasis and postoperative recurrence should be actively treated for a longer survival period.

The tumour microenvironment and immune milieu of cholangiocarcinoma

Tumour microenvironment is a complex, multicellular functional compartment that, particularly when assembled as an abundant desmoplastic reaction, may profoundly affect the proliferative and invasive abilities of epithelial cancer cells. Tumour microenvironment comprises not only stromal cells, mainly cancer-associated fibroblasts, but also immune cells of both the innate and adaptive system (tumour-associated macrophages, neutrophils, natural killer cells, and T and B lymphocytes), and endothelial cells. This results in an intricate web of mutual communications regulated by an extensively remodelled extracellular matrix, where the tumour cells are centrally engaged. In this regard, cholangiocarcinoma, in particular the intrahepatic variant, has become the focus of mounting interest in the last years, largely because of the lack of effective therapies despite its rising incidence and high mortality rates worldwide. On the other hand, recent studies in pancreatic cancer, which similarly to cholangiocarcinoma, is highly desmoplastic, have argued against a tumour-promoting function of the tumour microenvironment. In this review, we will discuss recent developments concerning the role of each cellular population and their multifaceted interplay with the malignant biliary epithelial counterpart. We ultimately hope to provide the working knowledge on how their manipulation may lead to a therapeutic gain in cholangiocarcinoma.

Ultrasonographic findings of intrahepatic lymphoepithelioma-like cholangiocarcinoma associated with Epstein-Barr virus: Two cases report

RATIONALE

Epstein-Barr virus (EBV)-related lymphoepithelioma-like cholangiocarcinoma (LELCC) is an extremely rare primary liver tumor with nonspecific clinical manifestations. The clinicopathological features of EBV-associated LELCC have been reported in a few cases. But reports of the tumor's imaging characteristics, particularly ultrasonographic findings, are very rare.

PATIENT CONCERNS

The first patient was a 64-year-old man with left upper quadrant pain and no nausea and dizziness for about 3 months. The second patient was a 40-year-old man, had an incidental finding of a hepatic tumor in a routine health checkup at a local hospital.

DIAGNOSES

In the first patient, the abdominal ultrasound demonstrated a slightly heterogeneous hypoechoic nodule in segment 3 of the liver. The nodule was about 2.0 cm × 1.7 cm in size, with a clear margin and regular shape. Color Doppler flow imaging (CDFI) revealed no blood flow signals in this nodule. According to the clinical information and imaging features, it was difficult to determine the diagnosis of the nodule. In the second patient, gray-scale ultrasound revealed a slightly heterogeneous hypoechoic mass measuring 3.5 cm × 2.5 cm with well-defined margin and regular shape at the superior segment of the left hepatic lateral lobe. There was a blurrily hypoechoic halo around the mass. In contrast-enhanced ultrasound (CEUS), the mass was homogeneous hyperenhancement in the arterial phase. In the portal phase and late phase, the center enhancement of the mass washed out gradually, presenting hypoenhancement, Therefore, the tumor was diagnosed as malignancy.

INTERVENTION

Finally, a laparoscopic left hepatic lateral lobectomy was performed in the first patient. The second patient underwent a left hepatectomy with cholecystectomy.

OUTCOMES

The first patient has been alive without recurrence or distant metastases for 11 months since the surgery. The second patient received routine follow-up after surgery. Until now, he has been tumor-free for 32 months.

LESSONS

We mainly focus on the ultrasound characteristics of EBV-associated LELCC, especially its enhancement patterns on CEUS, which may provide valuable information for diagnosis of the LELCC. When a liver tumor with typical CEUS patterns of malignancy is found in middle-aged adults with EBV positive, the possibility of EBV-related LELCC should be considered.

Programmed death-ligand 1 is upregulated in intrahepatic lymphoepithelioma-like cholangiocarcinoma

Intrahepatic lymphoepithelioma-like cholangiocarcinoma (LELCC) is a rare variant of cholangiocarcinoma. Here, we report the largest single series of LELCC cases yet studied (n = 13). We retrospectively analyzed the clinical data of the 13 patients and measured the expression of programmed death-ligand 1 (PD-L1) in tumors using immunohistochemical staining. We also analyzed 15 cases of conventional intrahepatic cholangiocarcinoma (IHCC) for comparison. We found that eight patients with LELCC were infected with Epstein-Barr Virus (EBV), and EBV infection correlated with poor prognosis in LELCC. Four patients among the five (80.0%) without EBV had a history of chronic viral hepatitis B. None of the 15 cases of conventional cholangiocarcinoma were positive for EBV. PD-L1 was expressed in both the tumor cells and tumor-infiltrating immune cells in LELCC patients at higher levels than in IHCC patients (P < 0.05). These observations suggest that EBV infection may promote the development of LELCC, and that PD-L1 may be a potential therapeutic target for treatment of EBV-associated LELCC.

Lymphoepithelioma-Like Carcinoma in Liver

Liver cancer, primarily encompassing hepatocellular carcinoma and intrahepatic cholangiocarcinoma, has become the second leading cause of worldwide cancer-related death during the past two decades. Lymphoepithelioma-like carcinomas (LELCs) are defined as tumors composed of undifferentiated epithelial cells with a prominent lymphoid infiltrate, and can arise in the liver as hepatocellular or cholangiocarcinoma forms. Patients with liver LELC display distinctive demographics and tumor characteristics. LELCs also appear to be associated with strikingly better outcomes compared to typical liver cancers, with 5-year survival rates of 57% to 100% versus 12% to 68%, respectively. Liver LELCs represent a unique model of immune response in liver cancer. Data on LELCs of the liver remain limited, and future comprehensive studies are needed to further elucidate this disease, which could ultimately offer precious insights for immunotherapeutic strategies in liver cancer.

Lymphoepithelioma-Like Cholangiocarcinoma Associated With HCV: A Case Report and a Review of the Literature

Lymphoepithelioma-like carcinoma is a particular form of undifferentiated carcinoma characterized by a prominent lymphoid stroma that was originally described in the nasopharynx. We present a case of hepatitis C virus (HCV)–associated lymphoepithelioma-like cholangiocarcinoma (LEL-CC), located at the liver, in a patient with history of malignancy. A 79-year-old man underwent partial hepatectomy with lymphadenectomy for a suspected metastasis of colon cancer 2.5 years after hemicolectomy for advanced colon cancer followed by adjuvant chemotherapy. The resected tumor was diagnosed as LEL-CC via a distinct histologic pattern with dense lymphoplasma cell infiltration. According to the available literature, our report describes a rare cases of HCV-associated LEL-CC that coexisted with other malignancy and that was associated with survival for more than 3 years after surgery, suggesting that surgical resection may be the recommended therapeutic option for LEL-CC to provide a definitive diagnosis as well as obtain a good prognosis, even in advanced stages of LEL-CC.

Intrahepatic Cholangiocarcinoma With Lymphoepithelioma-like Carcinoma Components Not Associated With Epstein-Barr Virus: Report of a Case

A carcinoma displaying undifferentiated features with dense lymphoplasmacytic infiltration is defined as lymphoepithelioma-like carcinoma (LELC). Intrahepatic cholangiocarcinoma (ICC) with LELC components is rare, and most LELCs are associated with Epstein-Barr virus (EBV). We report here on a case of ICC with LELC components not associated with EBV. A 65-year-old woman was incidentally found to have a hepatic tumor in the caudate lobe. An extended right hepatectomy with lymphadenectomy was performed. Histologically, the tumor was mainly composed of large undifferentiated epithelial cells with vesicular nuclei, prominent nucleoli, indistinct cell borders, and heavy small lymphocytic infiltration, which are the characteristic features of LELC. Immunohistochemical studies revealed that the tumor cells were positive for cytokeratin 19 but were negative for glypican 3. In situ hybridization using EBV-encoded RNA was negative. Therefore, a diagnosis of ICC with LELC components not associated with EBV was made. Because there is limited information available regarding the prognosis and treatment of ICC with LELC components because of the limited number of reported cases, additional studies will be needed to clarify the clinicopathologic features of this disease.

Clinicopathological features of 11 Epstein-Barr virus-associated intrahepatic cholangiocarcinoma at a single center in China

To date, only 20 cases of Epstein-Barr virus (EBV)-associated intrahepatic cholangiocarcinomas (IHCCs) have been reported in the literature.Pathology records of IHCC from January 1, 2007 to December 31, 2013 were retrieved from our hospital. Clinical information related to EBV-associated IHCC were also obtained, including gender, age at initial diagnosis, tumor size, tumor-node-metastasis stage, and follow-up duration. Surgically resected stage-matched EBV-negative IHCCs with full follow-up were selected for comparison. All liver specimens were fixed in 10% neutral-buffered formalin and paraffin-embedded tissue blocks containing cholangiocarcinoma and nonneoplastic liver tissue. Hematoxylin and eosin-stained sections were present in all cases.Among 329 primary IHCC patients, intranuclear expression of EBV was only found in 11 patients (3.3%), with an age range of 30 to 67 years (mean, 53.2 years; median, 54 years). The group consisted of 4 male and 7 female patients (M:F ratio 1:1.8). Histopathological analysis showed 1 case (9.1%) belonged to the typical lymphoepithelioma-like carcinoma (LELC), primarily composed of undifferentiated tumor cells intimately admixed with abundant lymphoplasmacytic cells. Two cases (18.2%) belonged to the conventional-type IHCCs, showing irregularly shaped neoplastic glands and scattered lymphoplasmacytic infiltration. The remaining 8 cases (72.7%) belonged to the lymphoepithelioma-like cholangiocarcinomas (LELCCs), showing varied glandular differentiation and dense lymphoplasmacytic infiltration. The overall survival of EBV-positive IHCCs was not significantly different from that of EBV-negative IHCCs (P = 0.512).Our data demonstrate that EBV-associated IHCC is very rare and may be subclassified into 3 different pathological types including LELC, conventional-type IHCC and LELCC on the basis of the tumor cellular differentiation, and host cellular immune responses in the tumors. The etiological, clinical, pathological, and molecular features are needed to be future studied by multicentric efforts in recruiting more EBV-associated IHCC patients.

Lymphoepithelioma-like cholangiocarcinoma: A mimic of hepatocellular carcinoma on imaging features

Primary lymphoepithelioma-like carcinoma in the liver is extremely rare. A few cases of lymphoepithelioma-like cholangiocarcinoma have been reported, but few radiologic features were described. We reviewed 23 cases of lymphoepithelioma-like cholangiocarcinoma reported between 1996 and 2014 and describe a rare case of a 35-year-old woman in our hospital who was diagnosed with lymphoepithelioma-like cholangiocarcinoma of the liver and was a hepatitis B carrier. The tumor (1.6 cm) in our patient appeared to be hypoechoic in sonographic images and hypodense in computed tomography (CT) images. In addition, it was homogeneous hypointense in T1-weighted magnetic resonance (MR) images (MRI) and hyperintense in T2-weighted MRI. Dynamic gadolinium-enhanced MRI showed typical image pattern of hepatocellular carcinoma (HCC). The patient underwent a laparoscopic left hepatic lobectomy, and the resected tumor consisted of well-differentiated glandular cells with extensive lymphocytic infiltration that were immunoreactive to CK (AE1/AE3), CD3, and CD20. In addition, the tumor was positive for Epstein-Barr virus-encoded RNA in situ hybridization. Finally, lymphoepithelioma-like cholangiocarcinoma was diagnosed. In previous studies, the incidence is highest among middle-aged people. Most tumors appeared to be hypodense with either hypovascular or hypervascular patterns in CT images. This case report is the first study to address sonography, CT, and MRI observations and delineate pathologic correlations. We suggest that the imaging pattern of lymphoepithelioma-like cholangiocarcinoma, either the typical cholangiocarcinoma pattern or a mimic of HCC, should be considered in the differential lists for HCC.

Pathologic classification of cholangiocarcinoma: New concepts

Herein, we propose a new pathologic classification of cholangiocarcinoma (CCA) based on recent progress in studies of preinvasive CCA lesions and the relationship of CCA to hepatic progenitor cells, as well as a new concept with respect to the pathologic similarities between biliary and pancreatic neoplasms. Depending on anatomical location, CCA is classifiable as intrahepatic (iCCA), perihilar (pCCA), and distal CCA (dCCA). iCCA is classifiable as the conventional type and the bile ductular type, whereas pCCA and dCCA mainly present as conventional adenocarcinoma. In addition, these three CCAs may present as the intraductal neoplasm type or rare variants. Bile ductular CCA resembles proliferating bile ductules and expressing hepatic progenitor cell phenotypes. Four types of preinvasive lesions are proposed: flat, papillary, tubular lesion, and cystic lesion. These lesions are eventually followed by invasive CCA. Interestingly, these preinvasive lesions have pancreatic counterparts. This CCA classification may introduce a new field of CCA research.

Lessons from rare tumors: Hepatic lymphoepithelioma-like carcinomas

In this review we focus on lymphoepithelioma-like hepatocellular carcinomas (LEL-HCC) and lymphoepithelioma-like cholangiocarcinomas (LEL-ICC). Despite their rarity, these tumors are of general interest because of their epidemiological and clinical features, and because they represent a distinct model of interaction between the immune system and neoplastic cells. Approximately half of LEL-HCC arise in the context of chronic hepatitis C virus (HCV) infection and have been described both in Eastern and Western patients. By contrast, LEL-ICC is associated in almost all cases with Epstein-Barr virus (EBV) infection and exhibits the same epidemiological features of EBV related malignancies. Compared with classical hepatocellular carcinoma and intrahepatic cholangiocarcinoma of corresponding stage, both LEL-HCC and LEL-ICC are characterized by lower rates of recurrence after surgery and better overall survival. How this behavior is related to distinct genetic alterations and tumor microenvironment is unclear. The pathophysiological mechanisms of lymphoid infiltrations seem to be different among the two groups of tumors. In fact, LEL-HCC frequently arises in the context of inflammatory changes driven by HCV infection, and has been recognized as a variant of classical hepatocellular carcinoma. At variance, lymphocyte recruitment of LEL-ICC is similar to that described in nasopharyngeal carcinoma and gastric LEL, and possibly depends on the expression pattern of latent EBV infection.

Characterization of inflammatory (lymphoepithelioma-like) hepatocellular carcinoma: a study of 8 cases

CONTEXT

The World Health Organization has recently recognized lymphoepithelioma-like carcinoma, or inflammatory hepatocellular carcinoma, as a variant of hepatocellular carcinoma.

OBJECTIVE

To identify and characterize the inflammatory hepatocellular carcinomas in our institution from 1988 to the present.

DESIGN

All cases of hepatocellular carcinoma in our institution from 1988 to the present were reviewed and reclassified as lymphoepithelioma-like carcinoma and were studied in comparison to appropriately matched controls.

RESULTS

Among the 8 cases of lymphoepithelioma-like carcinoma identified, the male to female ratio was 1:3, the mean age was 68.5 years (range, 57-78 years), and all of the cases were seen in noncirrhotic livers. The average numbers of lymphocytes were significantly higher in the cases than in the controls. T cells were predominant, with a uniform distribution of CD4 and CD8 positive cells. Cholangiolar differentiation was seen by K19 positivity as focal in 1 case and diffuse in 2 cases. In situ hybridization for Epstein-Barr virus was negative in all of the cases. Diffuse overexpression of p16 (>75% of cells) was seen in 2 cases, both of which were negative for the presence of transcriptionally active human papilloma virus by in situ hybridization. In our series, 3 of 8 cases (37.5%) showed local recurrence, which was similar to the controls (6 of 18; 33%), P > .99. Although the rate of distant metastases was lower among the cases (12.5%) than the controls (22.2%), the difference was not statistically significant (P > .99).

CONCLUSION

We present the first series of 8 cases of lymphoepithelioma-like carcinoma of the liver occurring in patients without cirrhosis and with a female preponderance and the absence of Epstein-Barr virus. Although clinical outcomes were similar to those of controls in our small series, additional data may be required for confirmation.

Epstein-Barr virus-associated lymphoepithelioma-like cholangiocarcinoma: a rare variant of intrahepatic cholangiocarcinoma with favourable outcome

AIMS

Lymphoepithelioma-like cholangiocarcinoma (LELCC) is a rare variant of intrahepatic cholangiocarcinoma (IHCC). Only 16 cases have reported previously in the literature, and about 62.5% of these cases were associated with Epstein-Barr virus (EBV).

METHODS AND RESULTS

We present the largest series (seven cases) of LELCC with descriptions of clinical and pathological characteristics, investigations of aberrant DNA methylation and mutation analyses of EGFR and KRAS. The evaluation also included 11 cases of stage-matched conventional IHCC for comparison.

RESULTS

All seven patients of LELCC were female and had stage I disease. LELCC had significantly better 2- and 5-year overall survival than IHCC (100% versus 52.8%, and 100% versus 13.2%, respectively, P = 0.003). All seven LELCCs were EBV-associated and composed exclusively of adenocarcinoma with varied glandular differentiation, dense lymphoplasmacytic infiltrate, and variable expression of biliary-type cytokeratins (CK7 and CK19) and stemness markers (CD133 and EpCAM). Gene hypermethylation was more frequent in LELCC than IHCC. CRBPI (85.7% versus 9.1%, P < 0.003) and CRBPIV (85.7% versus 0%, P < 0.001) showed statistically higher methylation frequencies in LELCC than IHCC. No LELCC harboured any EGFR or KRAS mutation.

CONCLUSION

Epstein-Barr virus-associated LELCC is a variant of IHCC, characterized by marked female predominance, favourable overall survival and distinctively frequent DNA hypermethylation.

Lymphoepithelioma-like hepatocellular carcinoma: a case report and a review of the literature

We report a rare case of lymphoepithelioma-like hepatocellular carcinoma. A 79-year-old Japanese man had undergone curative resection of extrahepatic bile ducts because of bile duct cancer 9 years prior. The bile duct cancer was diagnosed as mucosal adenocarcinoma, and the patient had been followed up every 6 months for the last 9 years. A recent computed tomography examination revealed a tumor, 4.2 cm in size, in the lateral segment of the liver. Based on the imaging findings, the tumor was diagnosed as hepatocellular carcinoma. Serology tests were negative for hepatitis B and C viruses. Chest and abdominal image analyses showed no evidence of metastasis, but a swollen lymph node was noted around the abdominal aorta. The patient subsequently underwent extended lateral segmentectomy and resection of the swollen lymph node. Microscopically, the tumor had the characteristic appearance of poorly differentiated hepatocellular carcinoma. Moreover, an abundant infiltration of inflammatory cells was observed in the tumor. Therefore, we diagnosed the tumor as lymphoepithelioma-like hepatocellular carcinoma. The resected para-aortic lymph node also had a carcinoma with features similar to those of the main tumor. The patient has been alive for 20 months since performance of the surgery. Since the first report of lymphoepithelioma-like hepatocellular carcinoma in 2000, only nine cases have been reported in the medical literature, and the clinicopathological features of the disease have not been well documented. Herein, we describe the clinicopathological features of this case for further understanding of the disease and review past cases in the literature.

Transplantation for cholangiocarcinoma

Cholangiocarcinoma (CCA) is a primary hepatic neoplasm that arises from malignant transformation of the biliary epithelium. Chronic biliary tree inflammation as occurs in primary sclerosing cholangitis (PSC) is a risk factor for the development of CCA. Surgical resection and liver transplantation following neoadjuvant therapy in patients with early extrahepatic CCA are the only potentially curative modalities. Biliary stenting, chemotherapy, radiation therapy, and photodynamic therapy are palliative treatment options for patients who are not surgical candidates. Liver transplantation following neoadjuvant therapy is an effective therapy for patients with hilar cholangiocarcinoma that is unresectable or arising in the setting of PSC.

Non-Epstein-Barr virus associated lymphoepithelioma-like carcinoma of the inferior common bile duct

A carcinoma displaying undifferentiated features with dense lymphoplasmacytic infiltration is defined as a lymphoepithelioma-like carcinoma (LEC), and some of LEC is associated with Epstein-Barr virus (EBV). All of the 13 previously reported cases of LEC of the biliary system were intrahepatic in location. Herein, we describe the first case of LEC of the inferior common bile duct. A 68-year-old Japanese man, who had been previously treated for hepatocellular carcinoma using microwave coagulation therapy, was found to have tumors of the common bile duct and pancreas head. Histopathological study of the resected tumor showed solid or cohesive nests of large undifferentiated cells with irregular large vesicular nuclei and nucleoli. Around the tumor cell nests, dense lymphoplasmacytic infiltration was observed. Focal glandular differentiation (approximately 5%) was also present. These histopathological features corresponded morphologically to LEC. Immunohistochemically, the tumor cells were positive for cytokeratin (CK) 7, CK 19 and CA19-9, but negative for CK 20 and Hep Par 1. In situ hybridization for Epstein Barr virus early small RNAs disclosed no nuclear signal in tumor cells. Therefore, a diagnosis of non-EBV-associated LEC of the inferior common bile duct was made. Although the prognosis of the biliary LEC is thought to be better than that of conventional cholangiocarcinoma, the differences in prognosis between EBV-positive and -negative cases have not yet been established. Therefore, additional case studies will be needed to clarify the clinicopathological features of LEC of the biliary tract.

Intrahepatic lymphoepithelioma-like cholangiocarcinoma not associated with epstein-barr virus: a case report

Lymphoepithelioma-like cholangiocarcinomas are rare tumors and most of them are related with Epstein-Barr virus (EBV) infection. Here, a case of a patient with lymphoepithelioma-like cholangiocarcinoma not associated with EBV infection is presented. In a 79-year-old man with hepatitis B virus-associated cirrhosis, a liver mass was detected on abdominal CT. Macroscopically, the resected tumor was pale gray, rubbery and well defined. Histologically, the tumor was composed of two components: an adenocarcinoma that formed irregular small glands and a lymphoepithelioma-like carcinoma that exhibited sheets of undifferentiated epithelial cells with lymphoid stroma. Lymphoplasmacytic infiltrates were more predominant in the lymphoepithelioma-like carcinoma than in the adenocarcinoma. Both components were roughly divided, but they gradually merged. Immunohistochemically, the adenocarcinoma component was diffusely positive for AE1/AE3, cytokeratin 7, cytokeratin 19 and epithelial membrane antigen, while the lymphoepithelioma-like carcinoma component was focally positive for them. However, both components were diffusely positive for p53 protein, and in situ hybridization using EBV-encoded RNA 1 was negative in both components as well. Examination of a resected para-aortic lymph node revealed metastasis exclusively of the lymphoepithelioma-like carcinoma component.

Pathological classification of intrahepatic cholangiocarcinoma based on a new concept

Intrahepatic cholangiocarcinoma (ICC) arises from the lining epithelium and peribiliary glands of the intrahepatic biliary tree and shows variable cholangiocytic differentiation. To date, ICC was largely classified into adenocarcinoma and rare variants. Herein, we propose to subclassify the former, based on recent progress in the study of ICC including the gross classification and hepatic progenitor/stem cells and on the pathological similarities between biliary and pancreatic neoplasms. That is, ICC is classifiable into the conventional (bile duct) type, the bile ductular type, the intraductal neoplasm type and rare variants. The conventional type is further divided into the small duct type (peripheral type) and large bile duct type (perihilar type). The former is a tubular or micropapillary adenocarcinoma while the latter involves the intrahepatic large bile duct. Bile ductular type resembles proliferated bile ductules and shows a replacing growth of the hepatic parenchyma. Hepatic progenitor cell or stem cell phenotypes such as neural cell adhesion molecule expression are frequently expressed in the bile ductular type. Intraductal type includes papillary and tubular neoplasms of the bile duct (IPNBs and ITNBs) and a superficial spreading type. IPNB and ITNB show a spectrum from a preneoplastic borderline lesion to carcinoma and may have pancreatic counterparts. At invasive sites, IPNB is associated with the conventional bile duct ICC and mucinous carcinoma. Biliary mucinous cystic neoplasm with ovarian-like stroma in its wall is different from IPNB, particularly IPNB showing cystic dilatation of the affected ducts. Rare variants of ICC include squamous/adenosquamous cell carcinoma, mucinous/signet ring cell carcinoma, clear cell type, undifferentiated type, neuroendocrine carcinoma and so on. This classification of ICC may open up a new field of research of ICC and contribute to the clinical approach to ICC.

Gastric carcinoma with osteoclast-like giant cells. Lymphoepithelioma-like carcinoma with Epstein-Barr virus infection is the predominant type

Osteoclast-like giant cells (OGC) are rare in gastric carcinomas. Histopathological study of seven gastric carcinomas with OGC demonstrated three distinct types: lymphoepithelioma-like carcinoma (LELC), non-LELC, and giant cell tumor (GCT) types. LELC is a poorly differentiated adenocarcinoma with prominent lymphoid stroma. The LELC type (n = 4) showed similar histology to LELC of the stomach, except that they were accompanied by OGC and granulomatous reaction. Epstein-Barr virus (EBV) infection was demonstrated by EBV-encoded RNA (EBER) in situ hybridization (ISH) in all the neoplastic cells. The non-LELC type (n = 2) consisted of EBV-negative carcinoma cells with inflammatory infiltrates. OGC and granulomas were frequently observed in the glandular lumens with accumulated mucus. The GCT type (n = 1) was a neuroendocrine carcinoma, containing many OGC with metaplastic bone formation, which showed typical morphological features of OGC in GCT of the bone. In all three types, OGC expressed CD68, but not cytokeratin, indicating that OGC had a reactive histiocytic lineage. Both LELC and non-LELC types are included in the differential diagnosis of isolated granulomatous gastritis, and EBER-ISH was useful for the identification of LELC type. Both LELC and no-LELC types were also suggested to have better prognoses, but the behavior of the GCT type needs to be further characterized.

Lymphoepithelioma-like cholangiocarcinoma not associated with EBV

Reported herein is an unusual case of intrahepatic cholangiocarcinoma with lymphoepithelioma-like appearance in a 64-year-old man who was found to have an intrahepatic mass without cirrhosis. The tumor had two distinct histological patterns with dense lymphoplasmacytic infiltrate. The first was similar to nasopharyngeal undifferentiated carcinoma; the second pattern was a well-differentiated adenocarcinoma. Transition between the two components was observed in the same duct. Immunohistochemistry indicated that the tumor was immunoreactive with AE1/AE3 and cytokeratin (CK) 7, but negative for CEA and CK20. Stromal inflammatory infiltrate primarily consisted of plasma cells and lymphocytes. Immunohistochemical examination and in situ hybridization for EBV showed no integration of the virus in the tumor cells. Intrahepatic lymphoepithelioma-like carcinoma is rare, and most are associated with EBV. Only three cases were not associated with EBV. The authors would like to add one more example of the tumors not associated with EBV.

Hepatocellular lymphoepithelioma-like carcinoma associated with epstein barr virus: a hitherto unrecognized entity

OBJECTIVE

Lymphoepithelioma-like carcinoma (LELC) is an undifferentiated carcinoma with a dense lymphoid stroma. It has been reported in diverse organs and shows variable association with Epstein-Barr virus (EBV). Only a few EBV positive cases have been observed in the hepatobiliary system, all of which were considered to be cholangiocarcinomas. We report a unique case of hepatocellular LELC arising in a cirrhotic liver with EBV demonstrated in the tumor cells.

METHODS AND RESULTS

A 39-year-old Hispanic female underwent an orthotopic liver transplant for end stage liver disease secondary to chronic hepatitis C. A high-grade hepatocellular carcinoma with a dense lymphocytic infiltrate was found in the explant as well as in a portal lymph node. Three months posttransplant, the patient developed numerous hepatic nodules with enlarged periaortic and portacaval lymph nodes. Biopsy of the hepatic nodules showed a recurrent hepatocellular carcinoma devoid of a dense lymphocytic infiltrate. Both the primary and recurrent tumors were positive for EBV by molecular studies. The patient eventually expired from liver failure over a 6-week period.

CONCLUSION

This case represents the first report of EBV-positive hepatocellular LELC. It is particularly interesting given the precipitous clinical outcome, which was possibly related to immunosuppresive therapy.

An approach to the surgical pathology of tumours and tumour-like conditions of the liver

Hepatic masses are increasingly being found, often as a result of more frequent and sophisticated imaging. Lesions can be detected during screening for primary and metastatic tumours, or as an incidental finding. Although some have distinctive radiological appearances allowing for a confident diagnosis, histological assessment of biopsy and resection specimens remains the cornerstone for the correct identification of many lesions. This broadsheet describes the distinctive features of common and uncommon hepatic tumours and outlines diagnostic problems and pitfalls, particularly for the benign and malignant tumours of hepatocytes and bile ducts. Tumour-like lesions that mimic malignancy are also discussed. Finally, an approach to the assessment of biopsies from probable metastatic tumours is presented, as this is one of the most common indications for liver mass biopsy for the practising pathologist.