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

Characterization of lymphocyte-rich hepatocellular carcinoma and the prognostic role of tertiary lymphoid structures

BACKGROUND & AIMS

Lymphocyte-rich hepatocellular carcinoma (LR-HCC) is largely unknown and a rare subtype of HCC with immune-rich stroma. Tertiary lymphoid structures (TLS), frequently observed in LR-HCC, are known to be prognostically significant in various malignancies; however, their significance in HCC remains unevaluated.

METHODS

Clinicopathologic data of 191 cases of surgically resected conventional HCC (C-HCC, n = 160) and LR-HCC (n = 31) were retrieved. Immunohistochemistry, multiplex immunofluorescence staining, RNA sequencing and proteomic analysis were conducted. Differences between the subtypes were statistically evaluated.

RESULTS

LR-HCC was significantly correlated to larger tumour size, higher Edmondson-Steiner grade, presence of TLS and higher CD3-, CD8- and FOXP3-positive T cell, high PD-1 and PD-L1 expression (p < .001 for all) compared to C-HCC. Patients with LR-HCC exhibited significantly better overall survival (OS) (p = .044) and recurrence-free survival (RFS) (p = .025) than C-HCC. LR-HCC demonstrated TLS signatures with significantly higher proteomic-based immune scores in 14 of 17 types of tumour-infiltrating immune cells. Furthermore, C-HCC with secondary follicles, the most mature form of TLS, exhibited significantly better OS (p = .031) and RFS (p = .033) than those without. Across the global proteome, LR-HCC was well-differentiated from C-HCC and a map of protein-protein interactions between tumour-infiltrating lymphocytes and HCC in tumour microenvironment was completed.

CONCLUSION

LR-HCC is clinicopathologically and molecularly distinct and shows better prognosis compared to C-HCC. Also, the presence of secondary follicle can be an important prognostic marker for better prognosis in both LR-HCC and C-HCC.

EpsteinBarr virusassociated lymphoepitheliomalike intrahepatic cholangiocarcinoma: A report of 3 cases and literature review

Hepatic lymphoepithelioma-like carcinoma (LELC) is an extremely rare malignant tumor characterized by undifferentiated malignant epithelial cells and significant lymphatic infiltration. Hepatic LELC mainly includes lymphoepithelioma-like hepatocellular carcinoma (LEL-HCC) and lymphoepithelioma-like intrahepatic cholangiocarcinoma (LEL-CC). Epstein-Barr virus (EBV) infection is considered as an important factor in LELC carcinogenesis. Since 2005, Xiangya Hospital of Central South University has treated a total of 3 patients with EBV-associated LEL-CC, which all showed liver masses by CT scans. After surgical resection, the EBV encoded RNA (EBER) and CK19 expression in all 3 patients were positive, and pathological examination confirmed EBV-associated LEL-CC. Two patients had a good postoperative prognosis, while 1 patient received relevant immunotherapy and chemotherapy after surgery. Based on the analysis of existing literature, the author believes that hepatic LELC can be included in the classification of liver tumors, which will provide new ideas for the accurate diagnosis and treatment of hepatic LELC.

Clinicopathological characteristics and molecular analysis of lymphocyte-rich hepatocellular carcinoma

Lymphocyte-rich hepatocellular carcinoma (LR-HCC), a newly proposed subtype of HCC, is characterized with abundant lymphocyte infiltration in the tumor. LR-HCC has a relatively good prognosis and is quite rare (<1% of all HCC). We examined LR-HCC clinicopathological and molecular characteristics by analyzing 451 surgically resected HCC cases without any prior treatment history at our hospital between 2012 and 2021. Clinicopathological features of LR-HCC and other HCCs (non-LR-HCC) were compared. Neoplastic and nonneoplastic hepatocytes from LR-HCC (n = 4) were collected with a laser microdissection system; RNA was extracted, followed by microarray analysis to examine lymphocytic infiltration-related molecular targets. Immunohistochemical staining of identified molecular target was performed in LR-HCC and non-LR-HCC. CD3, CD20, and CD8 immunostaining was also performed in LR-HCCs. There were 28 cases of LR-HCC (6%). No statistically significant differences were found in clinicopathological features, except for gross type, between LR-HCC and non-LR-HCC cases. The LR-HCC 5-year survival rate was >90%. Microarray analysis revealed high CCL20 expression in LR-HCC cases; immunohistochemical study showed significantly higher CCL20 expression in LR-HCC (P < 0.01) than in non-LR-HCC. CCR6, the only CCL20 receptor, was observed in infiltrating lymphocytes and HCC cells in LR-HCC. There were significantly more CD3-positive cells than CD20-positive cells (P < 0.0001) in tumor-infiltrating lymphocytes, most of which were CD8-positive T cells. In conclusion, there were no significant differences in clinicopathological characteristics between LR-HCC and non-LR-HCC, except for gross and LR microscopic features. CCL20 expression in LR-HCC may contribute to infiltration of large numbers of CD8-positive lymphocytes.

Frequent expression of PD-L1 in lymphocyte-rich hepatocellular carcinoma: A report of 4 cases

BACKGROUND

Programmed death ligand 1 (PD-L1) is an immune checkpoint inhibitor. PD-L1 binds to its receptor programmed death receptor (PD-1) expressed by immune cells and plays a key role in regulating immune responses. Engagement of PD-L1 on cancer cells and PD-1 on immune cells avoid destruction of tumour cells by immune cells. Immunostaining with PD-L1 has been suggested as a biomarker predictive of antiPD-L1 immunotherapy. Lymphocyte-rich hepatocellular carcinoma (LrHCC) is a rare histological HCC subtype which is characterised by neoplastic epithelial cells intermixed with numerous immune cells.

METHODS

Here in we investigated immunohistochemical PD-L1 expression in 4 cases of LrHCC. Tumour proportion score (TPS) and immune cell score was recorded. Immunophenotypic characterization of the tumour and inflammatory cells was also done. Epstein-Barr encoding region (EBER) in situ hybridization (ISH) assay as performed in all four tumours.

RESULTS

Expression of PD-L1 was demonstrated in tumour epithelial cells and immune cells in all four cases. Incomplete to membranous staining was demonstrated in the tumour cells. Tumour proportion score (TPS) was 1.2-20 %. Immune cells demonstrated membranous and cytoplasmic immunostaining. Immune cell score was ≥1 % to >10 %.

CONCLUSION

PD-L1 expression in both tumour and immune cells suggests distinct immunogenic feature and potential role of antiPD-L1 therapies in cases with inoperable disease.

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.

CK5/6-positive, P63-positive lymphoepithelioma-like hepatocellular carcinoma: A case report and literature review

BACKGROUND

Lymphoepithelioma-like carcinoma (LELC), a rare and unique variant of liver cancer, can be divided into lymphoepithelioma-like hepatocellular carcinoma and lymphoepithelioma-like intrahepatic cholangiocarcinoma. Dense lymphocytic infiltration is its characteristic pathological feature. In recent years, the number of reported cases of this type has increased each year. Studies have shown that lymphoepithelioma-like cholangiocarcinoma occurs more frequently in Asian women; LELC is associated with Epstein–Barr virus infection of liver cells of epithelial origin. Existing research shows that the prognosis of this tumour is good.

CASE SUMMARY

A 38-year-old female patient was hospitalized after 3 mo of abdominal pain and nausea. She had been infected with hepatitis B virus more than 10 years prior. The patient was hospitalized on January 21, 2022. Magnetic resonance imaging showed a 36 mm × 28 mm mass under the envelope of the left inner lobe of the liver. No metastasis of lymph nodes or other organs was observed. After left hemihepatectomy, biopsy and immunohistochemistry yielded a final diagnosis of lymphoepithelial hepatocellular carcinoma. After 12 mo of outpatient follow-up and chemotherapy, no tumour metastases were found on the latest computed tomography examination.

CONCLUSION

Herein, the patient was treated surgically and then followed up as an outpatient for 12 mo. This case will further expand our overall knowledge of the diagnosis and treatment of this rare tumor.

Single-center experience in the diagnosis and treatment of lymphoepithelioma-like hepatic carcinoma

PURPOSE

Lymphoepithelioma-like hepatic carcinoma (LELC) is a rare malignant liver tumor and its preoperative diagnosis is challenging. The aim of this study was to optimize the diagnosis and treatment of LELC in a single large center.

METHODS

We conducted this retrospective analysis of 16 patients diagnosed with LELC in the First Affiliated Hospital of Zhejiang University between 2010 and 2022. Thirty-two cases of cholangiocarcinoma (ICC) and 48 cases of hepatocellular carcinoma (HCC) served as controls.

RESULTS

Most of the 16 patients with LELC included in this study had no specific symptoms. Histologically, 9 patients had lymphoepithelioma-like hepatocellular carcinoma (LEL-HCC), 5 had lymphoepithelioma-like cholangiocarcinoma (LEL-ICC) and 2 had LEL-HCC-ICC. LEL-HCC was usually accompanied by hepatitis B virus infection, while LEL-ICC was often accompanied by Epstein Barr virus (EBV) infection. During the follow-up period, no complication and deaths were observed and only one patient experienced recurrence. These results were obviously better than those in patients with HCC and ICC.

CONCLUSION

LELC is a rare malignant hepatic tumor. There are no specific symptoms or imaging modalities for accurate preoperative diagnosis of LELC. The diagnosis can be confirmed by pathology; however, the prognosis of LELC after resection is promising.

Combined NK-CIK and PD-1 inhibitor (nivolumab), an effective immunotherapy for treating intrahepatic lymphoepithelioma-like cholangiocarcinoma unassociated with EBV infection: Two case reports and a literature review

Intrahepatic lymphoepithelioma-like cholangiocarcinoma (LELCC) is a very rare malignant tumor arising from the biliary epithelium. To date, there has been a lack of evidence on the radiographical features, clinicopathological features, and treatment modalities of LELCC, with less than 28 cases of LELCC without Epstein-Barr virus (EBV) infection having been reported worldwide. The treatment of LELCC remains unexplored. Here, we present two cases of patients with LELCC without EBV infection who were treated by liver resection, chemotherapy, and immunotherapy and who achieved long survival time. The patients received surgery to remove the tumors and then adjuvant chemotherapy using the GS regimen and combined immunotherapy involving natural killer-cytokine-induced killer (NK-CIK) and nivolumab were performed. Both patients had a good prognosis with a survival time of more than 100 months and 85 months.

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.

Lymphoepithelioma‑Like Cholangiocarcinoma with Hepatitis C Virus Infection Treated by Microwave Ablation: A Literature Review and Case Report

Background

Lymphoepithelioma-like cholangiocarcinoma (LELCC) is a rare type of intrahepatic tumor that is poorly understood. It is not associated with specific physical findings and is usually diagnosed incidentally, resulting in tumors that are often large-sized at diagnosis. At present, the main treatment approach is surgical resection.

Case Presentation

Here, we report the case of a patient with LELCC treated with microwave ablation (MWA). Our patient was a Chinese man with chronic hepatitis C and a 51 mm-diameter intrahepatic tumor. Despite blood testing, gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid-enhanced magnetic resonance imaging, and abdominal ultrasound, the tumor was not well diagnosed. However, the histopathological findings of ultrasound-guided percutaneous tumor biopsy led to a diagnosis of LELCC. The patient was treated with MWA, and no new lesions had occurred at 9 months after treatment.

Conclusion

To our knowledge, this is the first patient with LELCC treated using MWA. Our experience suggests that MWA is an effective new therapeutic method for this disease.

High PD-L1 Level of Advanced Hepatic Lymphoepithelioma-like Carcinoma Response Favorably to Lenvatinib plus Toripalimab

Lymphoepithelioma‐like carcinoma (LELC) is an uncommon subtype of primary liver cancer with predominant lymphocyte infiltration and a relatively favorable outcome. However, no standard treatment for advanced hepatic LELC has been established. Here, we give a first report of a 60‐year‐old man with advanced hepatic LELC who had a high expression of PD‐L1 in tumor cells and a high level of tumor‐infiltrating leukocytes (TILs) in the tumor microenvironment (TME). After receiving six cycles of multiple receptor tyrosine kinase inhibitor (rTKI) with lenvatinib plus PD‐1 inhibitor toripalimab treatment, the patient achieved persistent partial response (PR). Our report indicates that advanced hepatic LELC with high expression of PD‐L1 may benefit from the combination of rTKI and PD‐L1/PD‐1 blockade. Therefore, this potential strategy should be considered when treating those rare liver cancers.

Variant Hepatocellular Carcinoma Subtypes According to the 2019 WHO Classification: An Imaging-Focused Review

The 2019 5th edition of the WHO Classification of Digestive System Tumors estimates that up to 35% of hepatocellular carcinomas (HCCs) can be classified as one of eight subtypes defined by molecular characteristics: steatohepatitic, clear cell, macrotrabecular massive, scirrhous, chromophobe, fibrolamellar, neutrophil-rich, and lymphocyte-rich HCC. Due to their distinct cellular and architectural characteristics, these subtypes may not display the classic MRI features of HCC of arterial phase hyperenhancement (APHE) and washout appearance, creating challenges in noninvasively diagnosing such lesions as HCC. Moreover, certain subtypes with atypical imaging features have a worse prognosis than other HCCs. A range of distinguishing imaging features may help raise suspicion that a liver lesion represents one of these HCC subtypes. In this review, we describe the MRI features that have been reported in association with various HCC subtypes according to the 2019 WHO classification, with attention to current understanding of these subtypes' pathologic and molecular bases and relevance to clinical practice. Imaging findings that differentiate the subtypes from benign liver lesions and non-HCC malignancies are highlighted. Familiarity with these subtypes and their imaging features may allow the radiologist to suggest their presence, though histologic analysis remains needed to establish the diagnosis.

Human Papillomavirus-Associated Lymphoepithelioma-Like Carcinoma of the Anal Canal: A Case Report and Literature Review

Lymphoepithelioma-like carcinoma is a rare type of tumor that is histologically identical to lymphoepithelial carcinoma of the nasopharynx. Lymphoepithelioma-like carcinomas (LELCs) are closely associated with viral infections. Human papillomavirus (HPV)-associated LELCs have been reported in a variety of anatomic sites. We reported an extremely rare case of a 25-year-old woman with LELC derived from the anal canal, which is the second case reported at this site. The tumor was diffusely positive for p16 staining, and was correlated with high-risk HPV-16; Epstein-Barr virus-encoded small RNA was negative; PD-L1 positivity and abundant CD8+ T cell infiltration were observed, indicating a “hot” immune microenvironment. In reporting this case, we highlight the potential for misdiagnosis and suggested an association of HPV infection with LELC in the anal canal.

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.

Thymic Lymphoepithelial Carcinoma Associated with Epstein-Barr Virus: Experiences and Literature Review

Thymic lymphoepithelial carcinoma (TLEC) is a primary thymic carcinoma that accounts for about 14% of all thymic epithelial tumors and is classified into 14 types. The histological morphology is similar to lymphoepithelioma, a type of undifferentiated nasopharyngeal carcinoma. It has been reported that squamous carcinoma accounts for approximately 80% of thymic carcinoma, followed by TLEC, which accounts for 6%. TLEC has been reported to be associated with Epstein-Barr virus (EBV), with EBV infection in TLEC tumor cells first noted by Lyvraz et al. in 1985. Tumors shown to be EBV-positive are classified as TLEC if lymphoplasmacytic infiltration is lacking. However, only about 50% of the cases are positive for EBV, which is lower compared to nasopharyngeal lymphoepithelioma. Instances of EBV infection in other types of thymic epithelial tumor have been reported at lower rates, which suggests that EBV infection may have an important influence on the carcinogenesis of TLEC, though the etiology is unknown. TLEC is a highly malignant tumor with poor prognosis, as affected patients have a median survival time of 22 months, according to 58 cases from the literature, while the 5-year survival rate is 34.4%. Presently, prognosis is not considered to be affected by the presence or absence of EBV positivity.

Checkpoint Inhibition in the Treatment of Unresectable, Advanced Lymphoepithelioma-like Hepatocellular Carcinoma

Lymphoepithelioma-like hepatocellular carcinoma (LEL-HCC) is a very rare neoplasm, with distinct epidemiologic, morphologic and clinical characteristics. Molecular mechanistic insight into the pathogenesis of this carcinoma suggests a pivotal role for the host immune system in the proliferation and progression of this tumor. However, while detailed genomic profiling of these hepatic tumors have revealed an intra-tumoral inflammatory mutational signature that may predispose to immune checkpoint inhibitor efficacy, no published report has described their use in this tumor type. Unfortunately, with near 100 cases of LEL-HCC reported in the literature to date and the majority of cases confined to localized and resectable disease, current evidence-based practices in the unresectable setting are lacking, with unknown benefit of chemotherapy or immunotherapy. We report on the case of a 68 year-old man with unresectable, advanced LEL-HCC who had evidence of disease stability after starting on the immune checkpoint inhibitor nivolumab. His disease response persisted off therapy for over a year and was potentially augmented by radiotherapy at the site of local progression. For this extremely rare tumor subtype, this case highlights the potential efficacy and safety of immune checkpoint blockade in LEL-HCC and reinforces the need for more robust, large-scale analysis of patients with these rare tumors to better evaluate treatment strategies and outcomes.

Pathologic and molecular features of hepatocellular carcinoma: An update

Morphological diversity and several new distinct pathologic subtypes of hepatocellular carcinoma (HCC) are now well-recognized. Recent advances in tumor genomics and transcriptomics have identified several recurrent somatic/genetic alterations that are closely related with histomorphological subtypes and have therefore, greatly improved our understanding of HCC pathogenesis. Pathologic subtyping allows for a diagnosis which is clinically helpful and can have important implication in patient prognostication as some of these subtypes are extremely aggressive with vascular invasion, early recurrence, and worst outcomes. Several targeted treatments are now being considered in HCC, and the reporting of subtypes may be quite useful for personalized therapeutic purpose. This manuscript reviews the recently identified histomorphological subtypes and molecular alterations in HCC.

A Case of Lymphocyte-Rich Hepatocellular Carcinoma in a Patient Who Was Treated for Colon Cancer

Hepatocellular carcinoma (HCC) primarily originates in the liver with hepatic differentiation. However, HCCs are not homogenous, and approximately 35% of HCC cases are classified as histopathological variants that present distinct pathologic characteristics. In particular, the lymphocyte-rich variant is the rarest subtype accounting for less than 1% of HCCs, which is not well known to date about molecular features and pathophysiology. Herein, we present a case of a patient who was suspected of metastatic liver cancer and confirmed as lymphocyte-rich HCC pathologically. A 78-year-old woman who underwent a right hemicolectomy for colon cancer was referred to our hospital for a newly detected liver mass. We could not make a decision because of insufficient evidence for diagnosis from imaging studies. After resection, we found that it was a lymphocyte-rich HCC. The pathologic features and prognostic trends of this subtype are also discussed.