Florid Granulomatous Reaction in Epstein-Barr Virus-positive Nonendemic Burkitt Lymphomas

Tumor microenvironment of Burkitt lymphoma: different immune signatures with different clinical behavior

ABSTRACT

Burkitt lymphoma (BL) is characterized by a tumor microenvironment (TME) in which macrophages represent the main component, determining a distinct histological appearance known as "starry sky" pattern. However, in some instances, BL may exhibit a granulomatous reaction that has been previously linked to favorable prognosis and spontaneous regression. The aim of our study was to deeply characterize the immune landscape of 7 cases of Epstein-Barr virus-positive (EBV+) BL with granulomatous reaction compared with 8 cases of EBV+ BL and 8 EBV-negative (EBV-) BL, both with typical starry sky pattern, by Gene expression profiling performed on the NanoString nCounter platform. Subsequently, the data were validated using multiplex and combined immunostaining. Based on unsupervised clustering of differentially expressed genes, BL samples formed 3 distinct clusters differentially enriched in BL with a diffuse granulomatous reaction (cluster 1), EBV+ BL with typical starry sky pattern (cluster 2), EBV- BL with typical "starry sky" (cluster 3). We observed variations in the immune response signature among BL with granulomatous reaction and BL with typical "starry sky," both EBV+ and EBV-. The TME signature in BL with diffuse granulomatous reaction showed a proinflammatory response, whereas BLs with "starry sky" were characterized by upregulation of M2 polarization and protumor response. Moreover, the analysis of additional signatures revealed an upregulation of the dark zone signature and epigenetic signature in BL with a typical starry sky. Tumor-associated macrophages and epigenetic regulators may be promising targets for additional therapies for BL lymphoma, opening novel immunotherapeutic strategies.

Update: The molecular spectrum of virus-associated high-grade B-cell non-Hodgkin lymphomas

The vast spectrum of aggressive B-cell non-Hodgkin neoplasms (B-NHL) encompasses several infrequent entities occurring in association with viral infections, posing diagnostic challenges for practitioners. In the emerging era of precision oncology, the molecular characterization of malignancies has acquired paramount significance. The pathophysiological comprehension of specific entities and the identification of targeted therapeutic options have seen rapid development. However, owing to their rarity, not all entities have undergone exhaustive molecular characterization. Considerable heterogeneity exists in the extant body of work, both in terms of employed methodologies and the scale of cases studied. Presently, therapeutic strategies are predominantly derived from observations in diffuse large B-cell lymphoma (DLBCL), the most prevalent subset of aggressive B-NHL. Ongoing investigations into the molecular profiles of these uncommon virus-associated entities are progressively facilitating a clearer distinction from DLBCL, ultimately paving the way towards individualized therapeutic approaches. This review consolidates the current molecular insights into aggressive and virus-associated B-NHL, taking into consideration the recently updated 5th edition of the WHO classification of hematolymphoid tumors (WHO-5HAEM) and the International Consensus Classification (ICC). Additionally, potential therapeutically targetable susceptibilities are highlighted, offering a comprehensive overview of the present scientific landscape in the field.

Aggressive B-cell non-Hodgkin lymphomas: a report of the lymphoma workshop of the 20th meeting of the European Association for Haematopathology

Aggressive B-cell non-Hodgkin lymphomas are a heterogeneous group of diseases and our concepts are evolving as we learn more about their clinical, pathologic, molecular genetic features. Session IV of the 2020 EAHP Workshop covered aggressive, predominantly high-grade B-cell lymphomas, many that were difficult to classify. In this manuscript, we summarize the features of the submitted cases and highlight differential diagnostic difficulties. We specifically review issues related to high-grade B-cell lymphomas (HGBCLs) with MYC and BCL2 and/or BCL6 rearrangements including TdT expression in these cases, HGBCL, not otherwise specified, large B-cell lymphomas with IRF4 rearrangement, high-grade/large B-cell lymphomas with 11q aberration, Burkitt lymphoma, and pleomorphic mantle cell lymphoma. Since the workshop, the 5th edition of the WHO Classification for Haematolymphoid Tumours (WHO-HAEM5) and International Consensus Classification (ICC) 2022 were published. We endeavor to use the updated terminology.

Classic Hodgkin lymphoma with marked granulomatous reaction: A clinicopathologic study of 20 cases

Granulomatous reactions can be associated with various types of lymphoma, most commonly classic Hodgkin lymphoma (CHL). In some cases, the granulomatous reaction is extensive, obscuring the presence of neoplastic cells and potentially leading to delayed diagnosis and treatment. It is unknown if this subgroup of CHL has any unique clinicopathologic features. Here, we assessed the clinical and pathological features of 20 cases of CHL with a marked granulomatous reaction, defined in this study as granulomas representing ≥50% of the total cellularity/space of the specimen. This cohort of patients showed a male predominance (M:F ratio = 1.9:1) and 75% of patients were older than 40 years. Nineteen (95%) patients presented with lymphadenopathy with the neck/supraclavicular areas being most commonly involved (11/19; 58%). Advanced stage (III-IV) disease and B symptoms were present in 69% and 64% of patients, respectively. The morphologic features of these neoplasms fit best with mixed cellularity type. The Hodgkin and Reed-Sternberg (HRS) cells were positive for CD30, PAX5 (weak), pSTAT3 (80%), CD15 (70%), PD-L1 (67%), EBV-encoded small RNA (EBER)/LMP1 (50%) and CD20 (42%), and were negative for CD3, CD5, CD45, ALK and pERK. The histiocytes of the granulomas were positive for PD-L1 (67%), pSTAT3 (50%), and were negative for pERK and cyclin D1. Next generation sequencing using a 162-gene panel was negative for mutations in 4 cases. With a median follow-up of 58.9 months (range, 3.4-199.2 months), the median overall survival was 111 months and the 5-year overall survival was 78%. In summary, patients with CHL and a marked granulomatous reaction can present a diagnostic challenge and the pathologist must be alert to the possible presence of CHL to avert potential misdiagnosis. The histiocytes in the granulomas frequently express PD-L1, likely through the activation of the JAK/STAT pathway, suggesting a potential role for PD-1 blockade therapy in these patients.

Diagnostic approaches and future directions in Burkitt lymphoma and high-grade B-cell lymphoma

Since the 2016 WHO update, progress has been made in understanding the biology of Burkitt lymphoma (BL) and the concept of high-grade B-cell lymphomas (HGBCL) that allows some degree of refinement. The summary presented here reviews in detail the discussions of the Clinical Advisory Committee and expands upon the newly published 2022 International Consensus Classification for lymphoid malignancies (Campo et al. Blood, 2022). BL remains the prototypic HGBCL and diagnostic criteria are largely unchanged. HGBCL with MYC and BCL2 and HGBCL with MYC and BCL6 rearrangements are now separated to reflect biologic and pathologic differences. HGBCL, NOS remains a diagnosis of exclusion that should be used only in rare cases. FISH strategies for diffuse large B-cell lymphoma (DLBCL) and HGBCL are discussed in detail for these diseases. Advances in integrative analysis of mutations, structural abnormalities, copy number, and gene expression signatures allow a more nuanced view of the heterogeneity of DLBCL, NOS as well as definitions of HGBCL and point to where the future may be headed for classification of these diseases.

Burkitt lymphoma

Burkitt lymphoma (BL) is an aggressive form of B cell lymphoma that can affect children and adults. The study of BL led to the identification of the first recurrent chromosomal aberration in lymphoma, t(8;14)(q24;q32), and subsequent discovery of the central role of MYC and Epstein-Barr virus (EBV) in tumorigenesis. Most patients with BL are cured with chemotherapy but those with relapsed or refractory disease usually die of lymphoma. Historically, endemic BL, non-endemic sporadic BL and the immunodeficiency-associated BL have been recognized, but differentiation of these epidemiological variants is confounded by the frequency of EBV positivity. Subtyping into EBV⁺ and EBV^- BL might better describe the biological heterogeneity of the disease. Phenotypically resembling germinal centre B cells, all types of BL are characterized by dysregulation of MYC due to enhancer activation via juxtaposition with one of the three immunoglobulin loci. Additional molecular changes commonly affect B cell receptor and sphingosine-1-phosphate signalling, proliferation, survival and SWI-SNF chromatin remodelling. BL is diagnosed on the basis of morphology and high expression of MYC. BL can be effectively treated in children and adolescents with short durations of high dose-intensity multiagent chemotherapy regimens. Adults are more susceptible to toxic effects but are effectively treated with chemotherapy, including modified versions of paediatric regimens. The outcomes in patients with BL are good in high-income countries with low mortality and few late effects, but in low-income and middle-income countries, BL is diagnosed late and is usually treated with less-effective regimens affecting the overall good outcomes in patients with this lymphoma.

Burkitt lymphoma with a granulomatous reaction: an M1/Th1-polarised microenvironment is associated with controlled growth and spontaneous regression

AIMS

Burkitt lymphoma (BL) is an aggressive B-cell lymphoma that, in some instances, may show a granulomatous reaction associated with a favourable prognosis and occasional spontaneous regression. In the present study, we aimed to define the tumour microenvironment (TME) in four such cases, two of which regressed spontaneously.

METHODS AND RESULTS

All cases showed aggregates of tumour cells with the typical morphology, molecular cytogenetics and immunophenotype of BL surrounded by a florid epithelioid granulomatous reaction. All four cases were Epstein-Barr virus (EBV)-positive with type I latency. Investigation of the TME showed similar features in all four cases. The analysis revealed a proinflammatory response triggered by Th1 lymphocytes and M1 polarised macrophages encircling the neoplastic cells with a peculiar topographic distribution.

CONCLUSIONS

Our data provide an in-vivo picture of the role that specific immune cell subsets might play during the early phase of BL, which may be capable of maintaining the tumour in a self-limited state or inducing its regression. These novel results may provide insights into new potential therapeutic avenues in EBV-positive BL patients in the era of cellular immunotherapy.

Diffuse Large B-Cell Lymphoma With a Background of Extensive Granulomatous Inflammation: A Potential Pitfall for Misdiagnosis

Granulomatous inflammation has been reported to be associated with Hodgkin and non-Hodgkin lymphomas. Here, we report a case of recurrent diffuse large B-cell lymphoma (DLBCL) with extensive granulomatous inflammation that was initially misdiagnosed as granulomatous lymphadenitis. In 2019, a 75-year-old Caucasian male presented to our hospital with an enlarged right supraclavicular lymph node. He had a medical history of prostate cancer (in 2004), DLBCL (initially diagnosed in 2009), and rectal adenocarcinoma (in 2017), all of which responded well to treatment. In 2018, the patient had experienced right axillary adenopathy, weight loss, and intermittent night sweats. An excisional biopsy of a right axillary lymph node, performed at another institution, was diagnosed as granulomatous lymphadenitis. In 2019, at our hospital, an excisional biopsy of a right supraclavicular lymph node showed DLBCL in a background of granulomatous inflammation. A review of the prior right axillary lymph node biopsy also showed DLBCL with a background of extensive granulomatous inflammation. Chemotherapy was initiated and the patient’s follow-up showed a good response. We report this case to raise awareness that granulomatous inflammation may obscure the diagnosis of some neoplasms, such as DLBCL, which are less commonly known to have granulomatous inflammation. This may result in delayed treatment and may ultimately affect outcomes.

Prognostic Significance of Granuloma and Amyloid Deposition in Nasopharyngeal Carcinoma

The significance of granuloma and amyloid deposition in primary nasopharyngeal carcinoma (NPC) has yet to be investigated. This study aimed to evaluate their clinicopathologic associations. The histopathologic findings of 747 consecutive patients with primary NPC were retrospectively reviewed between January 2001 and December 2015. The presence of granulomas and amyloid deposits was observed in 68 (9.1%) and 62 (8.3%) patients, respectively. Granulomas were significantly associated with lower T classification, N classification, and overall TNM stage (p = 0.014, p = 0.006, and p = 0.001, respectively). Their presence was an independent predictor of overall survival (p = 0.033), disease-free survival (p = 0.034), and recurrence-free survival (p = 0.040). Conversely, amyloid deposition was not a predictor in any survival analyses. The present study demonstrated the prevalence of granuloma and amyloid deposition in the largest single institution cohort of primary NPC patients so far. Our results provide evidence that granulomas are significantly associated with better prognosis and treatment outcome. Further studies are needed to elucidate the mechanism of action of granuloma formation on the anti-tumor immunity of NPC.

The Formation and Function of Granulomas

Granulomas are organized aggregates of macrophages, often with characteristic morphological changes, and other immune cells. These evolutionarily ancient structures form in response to persistent particulate stimuli-infectious or noninfectious-that individual macrophages cannot eradicate. Granulomas evolved as protective responses to destroy or sequester particles but are frequently pathological in the context of foreign bodies, infections, and inflammatory diseases. We summarize recent findings that suggest that the granulomatous response unfolds in a stepwise program characterized by a series of macrophage activations and transformations that in turn recruit additional cells and produce structural changes. We explore why different granulomas vary and the reasons that granulomas are protective and pathogenic. Understanding the mechanisms and role of granuloma formation may uncover new therapies for the multitude of granulomatous diseases that constitute serious medical problems while enhancing the protective function of granulomas in infections.

Concomitant Epstein-Barr Virus-associated smooth muscle tumor and granulomatous inflammation of the liver

Epstein-Barr Virus-associated smooth muscle tumor (EBV-SMT) is a rare mesenchymal tumor typically seen in immunocompromised patients. Here, we report a case of EBV-SMT and associated granulomatous inflammation in the liver of a 32-year-old man with history of human immunodeficiency virus/acquired immune deficiency syndrome (HIV/AIDS). To our knowledge, an association of these two lesions has not been previously reported. We review the literature and discuss pathogenesis, differential diagnosis and immunohistochemical (IHC) stains helpful for the diagnosis of this rare entity. Finally, we consider possible explanations for the concomitant presence of these lesions.

ALK-positive anaplastic large cell lymphoma undiagnosed in a patient with tuberculosis: a case report and review of the literature

Background

Due to a similarity between the features of lymphoma and the features of tuberculosis, lymphoma may go unrecognized and undiagnosed in patients with tuberculosis.

Case presentation

A 33-year-old Thai man presented to our center with typical clinical manifestations of tuberculous lymphadenitis, with negative tests for both acid-fast bacilli and fungi, and negative polymerase chain reaction for Mycobacterial tuberculosis complex. The disease was not responding to anti-tuberculosis treatment and he developed both pericardial effusion and progressive lymphadenopathy. Large lymphoma cells were evident in the pericardial effusion, and a review of the previous lymph node biopsies confirmed the existence of ALK-positive anaplastic large cell lymphoma and tuberculous lymphadenitis. Moreover, when the tests were repeated, he was found to be positive for both acid-fast bacilli and Mycobacterial tuberculosis complex. The presence of typical morphology of tuberculous lymphadenitis and inattentional blindness may explain why the presence of large lymphoma cells was overlooked in one of the previous lymph node biopsies. Our patient developed severe pneumonia with profound septic shock due to carbapenem-resistant Enterobacteriaceae and died within days.

Conclusions

Given that tuberculosis and lymphoma can share common features, this case highlights the importance of thoroughly reviewing all foregoing relevant patient data (most notably pathology samples) in order to rule out the presence of lymphoma that may exist within the shadow of typical morphology of tuberculous lymphadenitis.

Does Every Necrotizing Granulomatous Inflammation Identified by NSCLC Resection Material Require Treatment?

Background

Lung cancer and tuberculosis (TB) are two major public health problems. They can coexist or appear sequentially. In patients with TB, lung cancer risk is increased. However, vice versa is not crystal clear. In this study, we aimed to determine the development of TB in patients with resectabled non-small cell lung cancer (NSCLC) in a 2-year postoperative follow-up period.

Material/Methods

We conducted a retrospective cohort study at three university hospitals. Patients who had NSCLC surgery between 2009 and 2013 were included and patient records were reviewed for the presence of necrotizing granulomatous inflammation (NGI) in resected specimens. Demographic properties, tumor type, stage, location, type of surgery, tuberculosis history, and thorax CT findings were recorded. We searched for the development of tuberculosis within a 2-year period after surgery.

Results

A total of 1027 patient cases were reviewed, of which 48 patients had NGI. The median age was 63 years. The most common type of cancer was squamous carcinoma; and lobectomy was the preferred operation (70.8%). Cancer involvement most commonly included the right lung (61.8%) and upper lobes (47,9%). Only 11 patients had anti-TB treatment postoperatively, which was based on radiological findings. Prior tuberculosis or anti-TB history, type, stage or localization of cancer, and adjuvant/neoadjuvant therapy were not found to be related to TB treatment. None of the study population had TB during the two-year follow-up period.

Treatment decisions appeared mostly related to physician experience. There was no difference in the risk of developing TB between patients with or without treatment. This finding may change the management of our patients.

Conclusions

Every NGI discovered in NSCLC resected material does not always require anti-TB treatment.

Granulomatous interstitial nephritis secondary to chronic lymphocytic leukemia/small lymphocytic lymphoma

Granulomatous interstitial nephritis (GIN) is an uncommon pathologic lesion encountered in 0.5% to 5.9% of renal biopsies. Drugs, sarcoidosis, and infections are responsible for most cases of GIN. Malignancy is not an established cause of GIN. Here, we report a series of 5 patients with GIN secondary to chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL). Patients were mostly elderly white males with an established history of CLL/SLL who presented with severe renal impairment (median peak serum creatinine, 7.3 mg/dL), leukocyturia, and mild proteinuria. One had nephromegaly. In 2 patients, the development and relapse of renal insufficiency closely paralleled the level of lymphocytosis. Kidney biopsy in all patients showed GIN concomitant with CLL/SLL leukemic interstitial infiltration. Granulomas were nonnecrotizing and epithelioid and were associated with giant cells. One biopsy showed granulomatous arteritis. One patient had a granulomatous reaction in lymph nodes and skin. Steroids with/without CLL/SLL-directed chemotherapy led to partial improvement of kidney function in all patients except 1 who had advanced cortical scarring on biopsy. In conclusion, we report an association between CLL/SLL and GIN. Patients typically present with severe renal failure due to both GIN and leukemic interstitial infiltration, which tends to respond to steroids with/without CLL/SLL-directed chemotherapy. The pathogenesis of GIN in this clinical setting is unknown but may represent a local hypersensitivity reaction to the CLL/SLL tumor cells.

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.

Granulomatous reaction in mediastinal B-cell non-Hodgkin lymphoma and intracardiac thrombosis

Epithelioid cell granulomas may be associated with several neoplasms. Lymphomas may mimic or are associated with epithelioid granulomas. In this article the authors report a child with granulomatous reaction in B cell non-Hodgkin lymphoma and intracardiac thrombosis. Although cancer alone is a risk factor for thromboembolism, thrombosis is a multifactorial disorder with both hereditary and acquired risk factors. This is the first reported case of intracardiac thrombosis with MTHFR A1298C and factor XIII V34L mutations together with granulomatous reaction in non-Hodgkin lymphoma.

Spontaneous Regression of Diffuse Large B-Cell Lymphoma Harbouring Epstein-Barr Virus: A Case Report and Review of the Literature

We report an elderly patient with diffuse large B cell lymphoma harbouring Epstein-Barr virus that showed spontaneous regressions with subsequent relapses three times. The patient died of aspiration pneumonia without any anti-neoplastic treatment 5 years 10 months after the initial onset of lymph node swelling. In the literature, there are several reports of aggressive non-Hodgkin's lymphoma cases that showed spontaneous regressions without relapse till the last observation. Over half of the cases were the extra-nodal type. The tendency toward regression of swollen lymph nodes detected by clinicians occurs within 2 weeks after biopsy. If the remaining lymph nodes show a tendency to decrease in size after biopsy without any anti-tumor therapies, the patient may develop spontaneous regression.

Burkitt's lymphoma: clinicopathologic features and differential diagnosis

Burkitt's lymphoma is a highly aggressive lymphoma identified and described in the last century by Denis Burkitt in Africa, in areas endemic for malaria. Since its description in African children, it has been recognized outside areas with endemic malaria, frequently also in children as well as among individuals with an underlying immunodeficiency. Since its initial designation as Burkitt's lymphoma, this type of lymphoma and lymphomas closely resembling it have received a variety of names in different classifications of lymphomas and leukemias: undifferentiated lymphoma, Burkitt's and non-Burkitt's type in the modified Rappaport Classification, malignant lymphoma, small non-cleaved cell, Burkitt's type in the Working Formulation, Burkitt's lymphoma and high-grade B-cell lymphoma, Burkitt-like in the REAL Classification, and acute lymphoblastic leukemia, L3 type in the FAB Classification. With the publication of the WHO Classification of Haematopoietic and Lymphoid Tumors, the nomenclature of this lymphoma has come full circle, and it is once again known simply as Burkitt's lymphoma. In recent years, efforts have focused on improving therapy for this rapidly proliferating neoplasm while minimizing, to the extent possible, treatment-associated toxicity. These efforts have led to the development of high-intensity, short-duration combination chemotherapy that has proven extremely effective for a high proportion of Burkitt's lymphoma patients. The differential diagnosis of Burkitt's lymphoma is broad, and precise diagnosis based on histologic, immunophenotypic, and genetic features remains the critical first step in planning appropriate therapy.

Granulomatous reactions cause symptoms or clinically imitate treatment resistance in small lymphocytic lymphoma/chronic lymphocytic leukaemia more frequently than in other non-Hodgkin lymphomas

AIMS

The electronic database of the institute of pathology, Medical University of Innsbruck, was reviewed and patient histories studied to analyse systematically the coincidence of granulomatous reactions and lymphomas in a large patient collective, and to find distinct clinicopathological correlations. Five cases of small lymphocytic lymphoma/chronic lymphocytic leukaemia (CLL) associated with granulomatous reactions in lymph nodes and bone marrow were identified, all clinically associated with signs of progressive disease.

METHODS

Cases were acquired by reviewing an electronic database comprising approximately 715,000 patients diagnosed between 1993 and 2003. Histochemical, immunohistochemical, and molecular techniques were used to verify diagnosis and associated infectious diseases. Clinical data were obtained from reviewing the charts.

RESULTS

Of 2044 bone marrow and 411 lymph node non-Hodgkin lymphoma biopsy samples, CLL was most frequently associated with bone marrow (two cases) and lymph node granulomas (three cases). These granulomas were mostly composed of epithelioid cells, with or without giant cells, and in all but one case did not show necrosis. All patients with CLL had clinical symptoms primarily caused by the granulomatous disease: two suffered from acid fast bacilli infections (Mycobacterium tuberculosis and mycobacteria other than tuberculosis) and three presented with clinical manifestations of sarcoidosis (the reason a diagnostic biopsy was performed).

CONCLUSIONS

Granulomatous reactions in patients with CLL might obscure diagnosis and imitate disease progression and Richter's transformation. Careful histological examination, exclusion of infectious agents, and a detailed clinical history are essential for correct diagnosis.