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

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.

Inflammatory Pseudotumor of the Liver

Hepatic inflammatory pseudotumor (IPT) describes a mass lesion composed of fibroblasts or myofibroblasts with a dense inflammatory infiltrate comprising lymphocyte, plasma cells, and histiocytes. These lesions are presumed to be an exuberant response to an infectious organism, although in most cases the causative agent is unknown. In specific circumstances, pathologists should consider ancillary techniques to exclude specific infections, such as mycobacteria, Candida, or syphilis. IgG4-related disease may cause a plasma-cell rich IPT. Finally, true neoplasms can mimic IPTs and must be excluded with appropriate ancillary studies, including inflammatory myofibroblastic tumor, follicular dendritic cell tumor, inflammatory angiomyolipoma, Hodgkin lymphoma, and inflammatory hepatocellular carcinoma.

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.

Lymphoepithelioma-like Hepatocellular Carcinoma: a Case Report and Review of Literature

We report a case of hepatic lymphoepithelioma-like carcinoma-hepatocellular carcinoma subtype (LEL-HCC) in a 41-year-old man with chronic hepatitis C virus (HCV) infection. The patient presented with abdominal pain and further assessment revealed a hypoechoic mass on ultrasonography. Serum alpha-fetoprotein (AFP) was 13·6 ng/dl. The patient was diagnosed as hepatocellular carcinoma based on the established triphasic computed tomography (TCT) diagnostic criteria and he underwent a surgical resection of the mass. Microscopic examination showed sheets and cords of malignant epithelial cells intermixed with heavy lymphoid infiltrate, with more than 100 tumor-infiltrating lymphocytes (TILs) per 10 high-power-field (HPF). Based on immunohistochemical studies, the malignant cells were positive for Hep Par 1 and glypican 3, focally positive for cytokeratin 7 (CK7), and negative for cytokeratin 20 (CK20). TILs were diffusely positive for cluster of differentiation 3 CD3 with an approximately equal CD4/CD8 ratio. The patient was recurrence free at 25 months after surgery, as evident by CT and serum alpha-fetoprotein level. LEL-HCC is a rare variant of HCC with a relatively better prognosis. Exploring the potential for immune modulator-based therapy in this subset of tumors is highly recommended.

Programmed cell death ligand 1 expression in a case of poorly differentiated lymphocyte-rich hepatocellular carcinoma

Our pathological study of a case of poorly differentiated lymphocyte-rich hepatocellular carcinoma suggested that immune checkpoint inhibitor may be an effective therapy. The histological type is an important factor in determining treatment choices.

Rare Histological Variants of Liver Cancer and Their Management: A Single-Institution Experience

Primary liver malignancies, including hepatocellular carcinoma (HCC) and cholangiocarcinoma, are a major cause of cancer-related morbidity and mortality worldwide. There are several histologically and biologically distinct subtypes of liver cancer that have previously been reported. However, literature regarding the nonsurgical management of these patients upon disease recurrence remains limited. These variants include combined HCC-cholangiocarcinoma (cHCC-CC), Epstein–Barr virus- (EBV-) associated carcinoma, undifferentiated carcinoma, and clear cell or thyroid-like variants of HCC. Here, we aim to highlight the pathologic features, clinical course, and outcomes of five patients with these unusual hepatic tumors and explain the rationale behind the choice of their systemic therapies upon disease recurrence. All patients underwent surgical resection as the standard of care for localized disease, and upon relapse, they were treated with either chemotherapy, targeted therapy, immunotherapy, or active surveillance based on the clinical context and tumor histology. These rare variants are important to recognize as they have prognostic and therapeutic implications, and there are currently insufficient data in the literature to guide further therapy.

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.

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.

Hepatocellular carcinoma: a review of diagnostic challenges for the pathologist

Histopathologists retain a critical role in the diagnosis and management of hepatocellular carcinoma (HCC). HCC arises usually but not exclusively in a background of advanced-stage chronic liver disease. The histological diagnosis of HCC poses many challenges particularly when dealing with liver biopsy specimens due to the heterogeneity of HCC and the difficulty to confirm hepatocellular differentiation in some instances. Primary liver tumors should be considered as a continuum with typical hepatocellular and cholangiocarcinoma at the two ends and a whole range of tumors showing both hepatocellular and cholangiocellular differentiation with or without an associated progenitor/stem cell component in the middle. Characterization of combined (or mixed) hepatocellular-cholangiocarcinoma can be very challenging. In advanced-stage chronic liver disease, the main challenge for the histopathologist is still to differentiate between HCC and its precursors, although this is rarely critical in the clinical setting at present. HCC originating in non-cirrhotic livers needs to be differentiated from other primary and extrahepatic tumors and from hepatocellular adenoma, bearing in mind that progression to malignancy is more through a continuum that watertight histological categories.

Lymphoepithelioma-like hepatocellular carcinoma: A case report and brief review of literature

RATIONAL

Lymphoepithelioma-like hepatocellular carcinoma (LEL-HCC) is a rare variant of hepatocellular carcinoma (HCC). To date, few cases have been reported in the literature, and almost no report in analyzing the different features of LEL-HCC.

PATIENT CONCERNS

We describe a 37-year-old female patient with a 32 × 30 mm mass in the right liver.

INTERVENTIONS

Complete surgical resection of the lesion was performed.

DIAGNOSES

Histopathological examination of the resected tumor revealed undifferentiated HCC cells with significant lymphocytes infiltration. Immunohistochemically, the tumor cells were positive for AFP (alpha fetoprotein), hepatocyte, CK8, and glypican-3. The patient was diagnosed with LEL-HCC.

OUTCOMES

The patient had a favorable clinical outcome, and was free from tumor recurrence after a 52-months follow-up.

LESSONS

Our case was the youngest patient of all the reported cases, and the third case who was infected with both hepatitis B virus (HBV) and hepatitis C virus (HCV). LEL-HCC is a rare variant of HCC, with a relatively favorable prognosis. Further research recruiting more patients is required to determine the accurate causes and mechanism of LEL-HCC.

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.

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.

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.

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.

Hepatoid carcinoma of the pancreas with lymphoid stroma: first description of the clinical, morphological, immunohistochemical, and molecular characteristics of an unusual pancreatic carcinoma

We report a case of tumour in the head of the pancreas observed in a 57-year-old man with a history of worsening jaundice and elevated alpha-fetoprotein (AFP) serum level, who underwent Whipple pancreatoduodenectomy. Histologically, the tumour was predominantly composed of solid sheets of large eosinophilic cells with a prominent lymphoid infiltration without association neither with DNA microsatellite instability nor Epstein-Barr virus infection. The tumour was diffusely and strongly positive for hepatocyte paraffin-1 (Hep Par-1) and glypican-3 leading to the diagnosis of hepatoid carcinoma. Strong cytoplasmic staining for AFP was focally observed. Moreover, tumour cells showed countless cytoplasmic eosinophilic globules immunoreactive for the stress protein p62. A primary hepatocellular carcinoma of the liver was ruled out by careful clinical analysis. Hepatoid carcinoma is an extremely rare pancreatic neoplasm, and here, we describe the first case of such variant associated with lymphoid stroma. The characteristic histologic features and the immunophenotypic profile help in distinguishing this carcinoma from other pancreatic tumours, notably from medullary carcinoma.

Lymphoepithelioma-like hepatocellular carcinoma: an uncommon variant of hepatocellular carcinoma with favorable outcome

Lymphoepithelioma-like hepatocellular carcinoma (LEL-HCC) is an uncommon variant of HCC with only 22 cases reported in the literature. To better determine the incidence, clinicopathologic features, prognostic significance, and molecular pathogenesis of LEL-HCC, we presented the largest series of LEL-HCC from a 9-year retrospective cohort of patients with HCC undergoing surgical resection. LEL-HCC was identified in 20 patients (4.9%). Compared with patients having HCC without significant tumor-infiltrating lymphocyte (TIL), patients with LEL-HCC had a relatively lower frequency of male sex (P=0.022), tended to present at early-stage disease (80.0% vs. 56.3% as AJCC stage I, P=0.037; 100% vs. 77.3% as BCLC stage 0/A, P=0.010), and all harbored a solitary tumor only (P=0.006). There was no significant difference in the age at presentation, underlying chronic liver disease, cirrhotic background, serum α-fetoprotein level, tumor size, histologic grade, and frequencies of vascular invasion. Most of the TILs in LEL-HCC were cytotoxic T lymphocytes. None of the LEL-HCCs was associated with Epstein-Barr virus. LEL-HCC was associated with better overall (5-y survival: 94.1% vs. 63.9%; P=0.007) and progression-free (5-y survival: 87.8% vs. 46.6%; P=0.002) survivals compared with HCC without significant TIL. The multivariate analysis revealed that LEL-HCC was an independent prognostic factor for overall and progression-free survivals. The adjusted hazard ratio of cancer death and tumor progression for LEL-HCC was 0.12 (P=0.037) and 0.14 (P=0.002), respectively. LEL-HCC did not differ in frequencies of microsatellite instability, BRAF mutation, and DNA hypermethylation. In brief, LEL-HCC is a distinct uncommon variant of HCC characterized by dense cytotoxic T-cell infiltration and favorable prognosis.

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.

Hepatocellular carcinoma: histologic considerations: pure, mixed, and motley

Hepatocellular carcinoma (HCC) is the most common primary malignant liver tumor seen in adults. The histopathologic diagnosis of classic or conventional differentiated HCC is seldom challenging, however, HCC is a particularly heterogeneous tumor. HCC often has a medley of morphologic features that are either challenging to recognize as hepatocellular, or represents components that are of complex histogenesis. This review focuses on the heterogeneous nature of HCC, with discussion of the histologic variants, some of which the clinical significance is unknown. In some cases, a lack of numbers precludes elucidating the clinical significance of these variants. Ultimately, larger studies are needed to determine the diagnostic and prognostic relevance of the phantasmagoria within HCC.

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.

Surgicopathological classification of hepatic space-occupying lesions: A single-center experience with literature review

Accompanying rapid developments in hepatic surgery, the number of surgeries and identifications of histological types of primary hepatic space-occupying lesions (PHSOLs) have increased dramatically. This has led to many changes in the surgicopathological spectrum of PHSOLs, and has contributed to a theoretical basis for modern hepatic surgery and oncological pathology. Between 1982 and 2009 at the Eastern Hepatobiliary Surgery Hospital (EHBH) in Shanghai, 31 901 patients underwent surgery and were diagnosed as having a PHSOL. In this paper, we present an analysis of the PHSOL cases at the EHBH for this time period, along with results from a systematic literature review. We describe a surgicopathological spectrum comprising more than 100 types of PHSOLs that can be stratified into three types: tumor-like, benign, and malignant. We also stratified the PHSOLs into six subtypes derived from hepatocytes; cholangiocytes; vascular, lymphoid and hemopoietic tissues; muscular, fibrous and adipose tissues; neural and neuroendocrine tissues; and miscellaneous tissues. The present study provides a new classification system that can be used as a current reference for clinicians and pathologists to make correct diagnoses and differential diagnoses among various PHSOLs.

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.

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

Lymphoepithelioma is a particular form of undifferentiated carcinoma, characterized by a prominent lymphoid stroma, originally described in the nasopharynx. Lymphoid stroma-rich carcinomas arising in other organs have been termed lymphoepithelioma-like carcinoma (LELC). In the liver, primary LELCs are very rare, and the majority has been identified as cholangiocarcinomas. Here a rare case of lymphoepithelioma-like hepatocellular carcinoma (HCC) is described. A 47-year old woman presented with abdominal pain. Ultrasonography revealed a liver nodule, 2.2 cm in diameter, localized in the right lobe, adjacent to the gallbladder. Viral markers for hepatic B virus (HBV), hepatic C virus (HCV) and Epstein-Barr virus (EBV) were negative. The nodule was hypoechogenic. The patient underwent surgery, with resection of the nodule. Histology showed hepatocellular carcinoma, characterized by a prominent lymphoid infiltrate. At immunocytochemistry, tumor cells were reactive for Hep Par1 and glypican 3. Immunophenotyping of tumor infiltrating lymphocytes evidenced the predominance of CD8+ cytotoxic suppressor T cells. The postoperative clinical outcome was favorable and the patient was recurrence-free 15 mo after resection. This case, to the best of our knowledge, is the first reported non EBV and non cirrhosis-associated lymphoepithelioma-like hepatocellular carcinoma. The association between the lack of EBV infection, the absence of cirrhosis, a “cytotoxic profile” of the inflammatory infiltrate and a good prognosis could identify a variant of lymphoepithelioma-like HCC with a favorable clinical outcome.