Association of t(14;18) translocation with HCV infection in gastrointestinal MALT lymphomas

Primary hepatic lymphoma of MALT type mimicking hepatic adenoma treated by hepatectomy: a case report and literature review

Background

Primary hepatic lymphoma (PHL) is a rare malignant tumor. Extranodal marginal zone lymphoma of the mucosa-associated lymphoid tissue (MALT) is an indolent lymphoma occurring at extranodal sites. The stomach is the most common organ affected by MALT lymphoma, whereas liver-related lymphoma is rarely reported. Its atypical clinical presentation often delays the diagnosis. Owing to the rarity of PHL, identifying its optimal treatment still remains a challenge. Herein, we report a case of PHL of the MALT type mimicking hepatic adenoma that was treated by hepatectomy without chemotherapy and review the scarce literature. Our findings suggest that surgery is an alternative approach to cure patients with localized hepatic lymphoma.

Case summary

A 55-year-old woman was admitted to our hospital because of upper abdominal discomfort, and a liver lesion was detected by computed tomography. She did not have nausea, fever, fatigue, jaundice, weakness, night sweats, or weight loss before admission. And her previous medical history was unremarkable. There were no positive signs on physical examination. Based on her preoperative examination including magnetic resonance imaging, the liver lesion was suspected to be a hepatic adenoma; however, the possibility of it being a malignancy like hepatocellular carcinoma was not excluded. Therefore, a decision of resection of the lesion was made. During the operation, hepatectomy of segment 4b and cholecystectomy were performed. The patient recovered well; however, after postoperative pathological examination, the lesion was diagnosed as a hepatic lymphoma of MALT type. The patient was reluctant to undergo chemotherapy or radiotherapy. At 18-month follow-up, no significant recurrence was observed, indicating that the treatment had a curative effect.

Conclusion

Notably, primary hepatic lymphoma of MALT type is a rare, low-grade B-cell malignancy. Making an accurate preoperative diagnosis of this disease is usually difficult, and liver biopsy is an appropriate avenue to improve the diagnostic accuracy. In patients with a localized tumor lesion, hepatectomy followed by chemotherapy or radiotherapy should be considered to achieve better outcomes. Although this study describes an unusual type of hepatic lymphoma mimicking a benign tumor, it has its inherent limitations. More clinical studies are required to establish guidelines for the diagnosis and treatment of this rare disease.

Hepatitis C virus-associated B-cell lymphomas: The importance of the new direct antiviral agent therapy

Hepatitis C virus (HCV) is a hepatotropic and lymphotropic virus, responsible for both chronic hepatitis and extra-hepatic manifestations. Multiple epidemiologic, clinical, biological, and molecular studies have suggested that HCV plays a causal role also in the development of several lymphoproliferative disorders, either benign, such as mixed cryoglobulinemia, or malignant, such as B-cell non-Hodgkin lymphomas (NHL). Chronic viral antigenic stimulation of B-lymphocytes plays a fundamental basic role from the onset of lymphoma to its final steps. In the past, several studies demonstrated that the association of pegylated interferon plus ribavirin was able to eradicate HCV, with subsequent regression of indolent B-cell low-grade NHL. Other studies have demonstrated that direct antiviral agents (DAAs) therapy have some efficacy in HCV-associated NHL, particularly in patients with low-grade NHL or marginal zone-lymphoma, but these results need to be confirmed in larger studies with longer follow-up. The response rate of antiviral therapy seems favorable also in high grade NHL when DAAs therapy is administered in combination with chemotherapy and therefore antiviral therapy should be considered as a first-line approach in HCV-related NHL.

HCV-related lymphoproliferative disorders in the direct-acting antiviral era: From mixed cryoglobulinaemia to B-cell lymphoma

HCV has been shown to induce many B-cell lymphoproliferative disorders. B lymphocytes specialise in producing immunoglobulins and, during chronic HCV infection, they can cause manifestations ranging from polyclonal hypergammaglobulinaemia without clinical repercussions, through mixed cryoglobulinaemic vasculitis to B-cell non-Hodgkin lymphoma. This spectrum is supported by substantial epidemiological, pathophysiological and therapeutic data. Many, although not all, of the pathogenic pathways leading from one extreme to another have been decrypted. Chronic viral antigen stimulation of B lymphocytes has a central role until the final steps before overt malignancy. This has direct implications for treatment strategies, which always include the use of direct-acting antivirals sometimes alongside immunosuppressants. The role of direct-acting antivirals has been well established in patients with cryoglobulinaemia vasculitis. However, their positive impact on B-cell non-Hodgkin lymphoma needs to be confirmed in larger studies with longer follow-up.

From hepatitis C virus infection to B-cell lymphoma

In addition to liver disorders, hepatitis C virus (HCV) is also associated with extrahepatic immune manifestations and B-cell non-Hodgkin lymphoma (NHL), especially marginal zone lymphoma, de novo or transformed diffuse large B-cell lymphoma and to a lesser extent, follicular lymphoma. Epidemiological data and clinical observations argue for an association between HCV and lymphoproliferative disorders. The causative role of HCV in NHL has been further supported by the response to antiviral therapy. Pathophysiological processes at stake leading from HCV infection to overt lymphoma still need to be further elucidated. Based on reported biological studies, several mechanisms of transformation seem however to emerge. A strong body of evidence supports the hypothesis of an indirect transformation mechanism by which sustained antigenic stimulation leads from oligoclonal to monoclonal expansion and sometimes to frank lymphoma, mostly of marginal zone subtype. By infecting lymphocytes, HCV could play a direct role in cellular transformation, particularly in de novo large B-cell lymphoma. Finally, HCV is associated with follicular lymphoma in a subset of patients. In this setting, it may be hypothesized that inflammatory cytokines stimulate proliferation and transformation of IgH-BCL2 clones that are increased during chronic HCV infection. Unraveling the pathogenesis of HCV-related B-cell lymphoproliferation is of prime importance to optimize therapeutic strategies, especially with the recent development of new direct-acting antiviral drugs.

Advances in HCV and Cryoglobulinemic Vasculitis in the Era of DAAs: Are We at the End of the Road?

Hepatitis C Virus (HCV)-related Mixed Cryoglobulinemia (MC) is a unique condition with complex pathogenesis that involves HCV antigen-driven B-lymphocyte clonal proliferation and mutagenesis. Clinical spectrum of MC ranges from asymptomatic state to clinically-apparent vasculitis involving multiple organs. In the era of Direct-Acting Antiviral (DAA) therapy, patients with HCV-related MC achieve high rates of viral clearance that is commonly accompanied by an improvement in clinical symptoms as well as immunological profiles. Rituximab, either alone or in combination with DAA, has also been shown to be effective. Nevertheless, there have been limited and somewhat conflicting data, particularly over the long-term, regarding the rate and degree of clinical response of MC following DAA therapy. It appears that we have come quite a long way in the last decade with this condition. As with non-MC related HCV, undoubtedly long term outcome data will be forthcoming over the next few years. As we move forward successful therapy of HCV is not likely to be a challenge in contrast to access to therapy.

The risk of HCV infection among health-care workers and its association with extrahepatic manifestations (Review)

Health care workers (HCWs) are frequently exposed to different biological agents during their activities and are frequently monitored. Among these infectious agents, human hepatitis C (HCV) can infect HCWs. In this review article, the risk of HCV infection among HCWs is discussed along with extrahepatic HCV-related malignancies, such as non‑Hodgkin lymphoma. Accidental contamination, represented by percutaneous and mucocutaneous infections is the main risk factor for such infection. The compliance of the protection procedures, included in the current regulation for HCWs, is the most important issue to reduce the risk of pathogen infections that in turn may produce reduction of infection‑associated malignancies.

Absence of t(14;18) chromosome translocation in agricultural workers after short-term exposure to pesticides

Exposure to pesticides represents a potential health risk for the general population and for agricultural workers in particular. Some researchers observed that occupational exposure to pesticides is associated with risk of non‑Hodgkin's lymphoma (NHL). The chromosomal translocation t(14;18)(q32;q21) is one of the most common chromosomal abnormalities in NHL. The aim of this study was to detect the effects of pesticides on t(14;18) chromosome translocation in agricultural workers after short-term exposure. Fifty-two workers occupationally exposed to pesticides (fungicides and insecticides) and 52 non-exposed were recruited. The farm workers were on average exposed to pesticides for ~3.7 h a day for 5 years. The frequency of BCL2-IGH t(14;18) translocation in workers occupationally exposed to pesticides was 10% (5 of 52) vs. 8% (4 of 52) in the control group. Overall, these data suggest that no significant association between occupational exposure to pesticides and an increased frequency of the chromosomal translocation BCL2-IGH t(14;18) in farmers was observed. However, further studies with a higher number of subjects exposed to pesticides are necessary to confirm this observation.

Hepatitis C virus-associated B-cell non-Hodgkin's lymphomas: what do we know?

Epidemiological studies have shown an increased risk of developing B-cell lymphomas in patients with chronic hepatitis C virus (HCV) infection. There is, however, a great geographic variability and it remains unclear whether additional environmental and genetic factors are involved or whether the international discrepancies represent simply a consequence of the variable prevalence of HCV infection in different countries. Other confounding factors may affect the comparability of the different studies, including the method of HCV assessment, the selection of normal controls, the lymphoma classification used and the year of publication. The most convincing evidence for a causal relationship comes from the observation, mainly limited to some indolent subtypes, of B-cell lymphoma regressions after successful HCV eradication with antiviral treatment. Yet, the molecular mechanism of HCV-induced lymphomagenesis are mainly hypothetical. According to most plausible models, lymphoma growth is a consequence of continuous antigenic stimulation induced by the chronic viral infection. This review will summarize the current knowledge on HCV-associated lymphomas and their management.

Colonic mucosa-associated lymphoid tissue lymphoma identified by chromoendoscopy

Colonic mucosa-associated lymphoid tissue (MALT) lymphomas are a rare occurrence and the definitive treatment has not been established. Solitary or multiple, elevated or polypoid lesions are the usual appearances of MALT lymphoma in the large intestine and sometimes the surface may reveal abnormal vascularity. Herein, we report a case of MALT lymphoma and review the relevant literature. Upon colonoscopy, a suspected pathologic lesion was observed in the proximal transverse colon. The lesion could be distinguished more prominently after using narrow-band imaging mode and indigo carmine-dye spraying chromoendoscopy. Histopathologic examination of this biopsy specimen revealed lymphoepithelial lesions with diffuse proliferation of atypical lymphoid cells effacing the glandular architecture and centrocyte-like cells infiltrating the lamina propria. Immunohistochemical analyses showed that tumor cells were positive for CD20 and Bcl-2e, and negative for CD10, CD23, and Bcl-6. According to Ann-Arbor staging system, the patient had stage II_E. A partial colectomy with dissection of the paracolic lymph nodes was performed. Until now, there is no recurrence of lymphoma at follow-up.

A clinical perspective on the role of chronic inflammation in gastrointestinal cancer

Chronic inflammation has been identified as an important risk factor for the development of malignancy, and knowledge about its molecular and cellular mechanisms is increasing. Several chronic inflammatory diseases of the gastrointestinal tract are important as risk factors for malignancy and have been studied in detail. In this review, we summarize important molecular mechanisms in chronic inflammation and highlight established and potential links between chronic inflammation and gastrointestinal cancer. In addition, we present the role of chronic inflammation in numerous tumors within the gastrointestinal tract as well as the relevant pathways or epidemiologic observations linking the pathogenesis of these tumors to inflammation.

Hepatitis C-associated B-cell non-Hodgkin lymphomas. Epidemiology, molecular signature and clinical management

There is ample epidemiologic evidence for an association of chronic hepatitis C virus (HCV) infection with B-cell non-Hodgkin lymphoma (B-NHL). B-NHL subtypes most frequently associated with HCV are marginal zone lymphoma and diffuse large B-cell lymphoma. The most convincing evidence for a causal relationship between HCV infection and lymphoma development is the observation of B-NHL regression after HCV eradication by antiviral therapy (AVT). In fact, for indolent HCV-associated B-NHL, first-line AVT instead of standard immune-chemotherapy might be considered. Molecular mechanisms of HCV-NHL development are still poorly understood. Three general theories have emerged to understand the HCV-induced lymphomagenesis: (1) continuous external stimulation of lymphocyte receptors by viral antigens and consecutive proliferation; (2) HCV replication in B cells with oncogenic effect mediated by intracellular viral proteins; (3) permanent B-cell damage, e.g., mutation of tumor suppressor genes, caused by a transiently intracellular virus ("hit and run" theory). This review systematically summarizes the data on epidemiology, interventional studies, and molecular mechanisms of HCV-associated B-NHL.

A tailored health surveillance program unveils a case of MALT lymphoma in an HCV-positive health-care worker

Non-Hodgkin lymphoma (NHL) may occur among hepatitis C virus (HCV)-infected individuals. HCV is one of the most common blood-borne pathogens transmitted from patients to health-care workers (HCWs). The development of NHL among HCV-infected HCWs has recently been shown. To investigate this issue further a tailored health surveillance program was applied to 3,138 HCWs from four Medical Institutions. To this aim, all employees were screened for both anti-HCV antibodies and HCV-related extrahepatic manifestations. The HCV prevalence rate, similar among all the HCW subgroups, was 7.3%. The occurrence of a gastric mucosa-associated lymphoma tissue (MALT) lymphoma, diagnosed in a physician following a long history of HCV chronic infection, was observed. Molecular characterization of MALT tissue indicated that immunoglobuline gene combinations were those usually found among HCV-associated lymphomas. Furthermore, B-cell expansion exhibited t(14;18) translocation, as a genetic abnormality associated with the development of MALT lymphomas from HCV-positive patients. Overall, these findings support the hypothesis that HCV viral infection potentially affects the pathway of transformation and progression of lymphoma cells. The occurrence of B-cell NHL, among HCV-positive HCWs, is an additional reason to apply the standard precautions to reduce the risk of blood-borne pathogen transmission.

Molecular signature in HCV-positive lymphomas

Hepatitis C virus (HCV) is a positive, single-stranded RNA virus, which has been associated to different subtypes of B-cell non-Hodgkin lymphoma (B-NHL). Cumulative evidence suggests an HCV-related antigen driven process in the B-NHL development. The underlying molecular signature associated to HCV-related B-NHL has to date remained obscure. In this review, we discuss the recent developments in this field with a special mention to different sets of genes whose expression is associated with BCR coupled to Blys signaling which in turn was found to be linked to B-cell maturation stages and NF-κb transcription factor. Even if recent progress on HCV-B-NHL signature has been made, the precise relationship between HCV and lymphoma development and phenotype signature remain to be clarified.

Hepatitis C virus infection in the immunocompromised host: a complex scenario with variable clinical impact

The relationship between Hepatitis C Virus (HCV) infection and immunosuppression is complex and multifaceted. Although HCV-related hepatocytolysis is classically interpreted as secondary to the attack by cytotoxic T lymphocytes against infected cells, the liver disease is usually exacerbated and more rapidly evolutive in immunosuppressed patients. This generally occurs during the immunosuppression state, and not at the reconstitution of the host response after immunosuppressive therapy discontinuation. The field of immunosuppression and HCV infection is complicated both by the different outcome observed in different situations and/or by contrasting data obtained in the same conditions, with several still unanswered questions, such as the opportunity to modify treatment schedules in the setting of post-transplant follow-up. The complexity of this field is further complicated by the intrinsic tendency of HCV infection in itself to lead to disorders of the immune system. This review will briefly outline the current knowledge about the pathogenesis of both hepatic and extrahepatic HCV-related disorders and the principal available data concerning HCV infection in a condition of impairment of the immune system. Attention will be especially focused on some conditions - liver or kidney transplantation, the use of biologic drugs and cancer chemotherapy - for which more abundant and interesting data exist.

Hepatitis C and non-Hodgkin lymphoma: the clinical perspective

Hepatitis C virus (HCV) is a commonly transmitted infection that has both hepatic and extrahepatic repercussions. These range from the inflammatory to the oncologic with an undisputed link to hepatitis, liver cirrhosis, and hepatocellular carcinoma. Its role in the development of B cell non-Hodgkin lymphoma (B-NHL) is becoming better understood, leading to opportunities for research, therapy, and even prevention. Research in the field has progressed significantly over the last decade, with the number of patients diagnosed with HCV and B-NHL rising incrementally. It is therefore becoming crucial to fully understand the pathobiologic link of HCV in B cell lymphomagenesis and its optimal management in the oncologic setting.

The transcription factor YY1 is a substrate for Polo-like kinase 1 at the G2/M transition of the cell cycle

Yin-Yang 1 (YY1) is an essential multifunctional zinc-finger protein. It has been shown over the past two decades to be a critical regulator of a vast array of biological processes, including development, cell proliferation and differentiation, DNA repair, and apoptosis. YY1 exerts its functions primarily as a transcription factor that can activate or repress gene expression, dependent on its spatial and temporal context. YY1 regulates a large number of genes involved in cell cycle transitions, many of which are oncogenes and tumor-suppressor genes. YY1 itself has been classified as an oncogene and was found to be upregulated in many cancer types. Unfortunately, our knowledge of what regulates YY1 is very minimal. Although YY1 has been shown to be a phosphoprotein, no kinase has ever been identified for the phosphorylation of YY1. Polo-like kinase 1 (Plk1) has emerged in the past few years as a major cell cycle regulator, particularly for cell division. Plk1 has been shown to play important roles in the G/M transition into mitosis and for the proper execution of cytokinesis, processes that YY1 has been shown to regulate also. Here, we present evidence that Plk1 directly phosphorylates YY1 in vitro and in vivo at threonine 39 in the activation domain. We show that this phosphorylation is cell cycle regulated and peaks at G2/M. This is the first report identifying a kinase for which YY1 is a substrate.

Japanese case of follicular lymphoma of ocular adnexa diagnosed by clinicopathologic, immunohistochemical, and molecular genetic techniques

Background

Follicular lymphomas of the ocular adnexa are very rare in Japan, with only two reported cases.

Case

A 44-year-old woman visited our clinic for treatment of ocular adnexal tumors in both eyes.

Findings

Histologic examination showed that the neoplastic lesions consisted of atypical lymphoid cells, and the tentative diagnosis was malignant lymphoma. Immunophenotypic analyses by flow cytometry and immunohistochemistry showed that the atypical lymphoid cells expressed CD45, bcl-2, CD10, CD19, CD20, IgM, and kappa light chains. The cells were negative for CD5 and other T, natural killer, or myelomonocyte antigens. Southern blot hybridization demonstrated gene rearrangement bands in the immunoglobulin JH region. Fluorescence in situ hybridization studies showed a translocation at t(14,18)(q32,q21). Systemic evaluations detected enlargements of both the inguinal lymph nodes and parabronchial lymph nodes.

Conclusion

Our results show that flow cytometry, molecular genetic analyses, and chromosomal examination can be useful in differentiating follicular lymphoma from marginal zone B cell lymphoma of mucosa-associated lymphoid tissue and reactive lymphoid hyperplasia.

Hepatitis C virus-induced cryoglobulinemia

In this review we discuss the clinical manifestations, pathogenesis, and treatment of hepatitis C virus (HCV)-related cryoglobulinemia. HCV is a major cause of liver-related morbidity and is increasingly recognized as an instigator of B-cell lymphoproliferative disorders such as mixed cryoglobulinemia and non-Hodgkin lymphoma. Cryoglobulinemia is characterized by the clonal expansion of rheumatoid factor-expressing B cells in the liver, lymph nodes, and peripheral blood, resulting in the presence of cryoglobulins in the circulation. Cryoglobulins are cold-insoluble immune complexes containing rheumatoid factor, polyclonal IgG, and HCV RNA that precipitate and deposit on vascular endothelium, causing vasculitis in organs such as the skin, kidneys, and peripheral nerves. A subset of patients develops a low-grade lymphoma composed of B cells that are immunophenotypically similar to the expanded B cells seen in cryoglobulinemia. HCV-related B-cell lymphoproliferative disorders likely comprise a spectrum of disease, ranging from asymptomatic clonal B-cell expansions to pathogenic cryoglobulinemia and lymphoma. It is unclear how B cells become dysregulated during the course of chronic HCV infection, and continued patient-centered research is necessary to elucidate the pathogenesis of HCV-related B-cell dysregulation.

Characterization of the light chain-restricted clonal B cells in peripheral blood of HCV-positive patients

To investigate the association between hepatitis C virus (HCV) and B cell proliferation, we searched for the clonal B cells by flow cytometric analysis of the surface immunoglobulin kappa (kappa):lambda (lambda) light chain ratios of the circulating B (CD19+) cells in 240 HCV-positive patients and 150 negative controls with liver diseases. Clonal B cells with light chain restriction (kappa:lambda ratio >3:1 or <1:2) were analyzed for CD5 expression and the presence of monoclonal immunoglobulin heavy-chain (IGH) gene rearrangements and the t(14;18) chromosomal translocation. Clonal B cells were detected in 7 cases with HCV (2.9%), but was never detected in the controls (p < 0.05). Of the 7 cases, all had monoclonal IGH gene rearrangements and one had the t(14;18) chromosomal translocation. These HCV-related clonal B cells are not uniform in the intensity of CD5 expression and showed no increase in the frequencies of CD5+ population compared with non-clonal B cells. No "chronic lymphocytic leukemia-phenotype" cells were found. The loss of clonality was observed in 2 cases treated with interferon and in one case treated with splenectomy. The longitudinal study is required to determine whether these circulating clonal B cells progress to lymphoproliferative disorders in future or not.