Fibrin-Associated, EBV-Negative Diffuse Large B-Cell Lymphoma Arising in Atrial Myxoma: Expanding the Spectrum of the Entity

From the archives of MD Anderson Cancer Center: EBV-positive fibrin-associated large B-cell lymphoma in an ovarian leiomyoma with cystic degeneration: A case report and discussion of differential diagnosis

Fibrin-associated large B-cell lymphoma (FA-LBCL) is a rare type of lymphoma usually associated with Epstein-Barr virus (EBV) infection. We report a case incidentally detected in a right ovarian mass of a 53-year-old woman. The patient presented with bloating and weight gain over 8 months. Imaging studies showed a 20.7 cm, complex right adnexal mass. Total abdominal hysterectomy and bilateral salpingo-oophorectomy were performed. Macroscopic examination revealed a 25 x 18.5 x 9.5 cm predominantly cystic right ovarian mass with focal solid areas. Microscopically, most of the mass was a leiomyoma with hyaline necrosis and extensive cystic degeneration. In areas, the cyst showed focally necrotic, fibrinous material associated with small aggregates of round and atypical lymphoid cells with prominent karyorrhexis and mitotic activity These large cells were confined within the cystic spaces. Immunohistochemical analysis showed that the atypical cells were positive for CD20, CD30, CD79a and MUM1/IRF4, and were negative for CD3, CD10 and BCL6, supporting B-cell lineage. In situ hybridization for Epstein-Barr virus-encoded RNA (EBER ISH) was also positive in the atypical cells supporting the diagnosis of EBV-positive fibrin-associated large B-cell lymphoma. The patient subsequently received four cycles of chemotherapy using rituximab, cyclophosphamide, doxorubicin, vincristine and prednisone (R-CHOP). Computed tomography (CT) scan of the neck, chest, abdomen and pelvis 5 months after the last chemotherapy cycle showed no evidence of disease. After a follow-up of 17 months, the patient is alive with no evidence of disease. This report is being used to discuss the salient features of this rare entity and its differential diagnosis.

Fibrin-Associated Large B-Cell Lymphoma (FA-LBCL) Involving Solid Organs as Necrotic Cystic Lesions-A Rare Entity with Potential Diagnostic Pitfalls: A Two-Case Series and Review of the Literature

Fibrin-associated large B-cell lymphoma (FA-LBCL) is a rare subtype of Epstein-Barr virus (EBV)-associated lymphoma, recognized as an independent entity per the 5th edition of the WHO classification of hematolymphoid neoplasms. It is usually associated with longstanding chronic inflammation and arises within fibrinous material in confined anatomic spaces. We report the clinicopathologic manifestations of two patients of FA-LBCL involving the adrenal gland and kidney. Both tumors were diagnosed after presenting as cystic masses on imaging studies. These lymphomas were non-invasive, with microscopic aggregates of large B-lymphoma cells along/within cystic wall and admixed with fibrinous material and without prominent inflammation. By immunohistochemistry and in-situ hybridization, lymphoma cells were positive for CD45, PAX5, CD79a, MUM1, BCL2, PD-L1, and EBV/EBER (Epstein-Barr virus encoded small RNA) with a high proliferation index. Both patients remain in remission after management with complete surgical resection and additional chemo-immunotherapy in one patient. Considering its rarity, scant tumor cells, and varied clinical presentations, FA-LBCL may pose diagnostic challenges, especially when presenting as extensively necrotic cystic lesions, needing multidisciplinary collaboration in formulating management.

[Cardiac myxoma: biological features, morphology, differential diagnosis]

Cardiac myxoma in its morphology is a typical benign tumor, meanwhile, the fact of its localization in the heart chamber, directly in the constant blood flow, largely determines the clinical behavior of this neoplasm, which is often manifested by the development of characteristics that formally determine the aggressive and even malignant nature of the course. Accordingly, the malignancy of cardiac myxoma is determined more by its clinical behavior (recurrence, multifocality of the lesion, the presence of mechanisms of spread similar to metastasis) rather than by its histological picture. In the structure of primary benign tumors of the heart, myxoma occupies a dominant position and its incidence is up to 85%. According to some authors, the tumor develops from multipotent mesenchymal stem cells of the endocardium, mainly in the area of the fossa ovale, while according to others the histogenesis of the tumor remains unclear. The obligate morphology element is the myxoma cell. The presence of so-called "ring" structures is special, regular and highly specific, and Gamna - Gandy bodies, foci of calcification and superficial thrombosis are considered characteristic secondary destructive morphological signs. The review describes the morphology features, specific clinical manifestations, immunohistochemical parameters of cardiac myxoma, and presents information available in the literature on the mechanisms of tumor spread (metastasis).

EBV-negative Fibrin-Associated Large B-Cell Lymphoma Arising in Thyroid Hyperplastic Nodule: Report of a Case and Literature Review

Fibrin-associated large B-cell lymphoma is a rare microscopic-sized tumor, typically representing an unexpected finding at sites rich in chronic fibrin deposition. It is associated with Epstein-Barr virus, and has been reported to occur in a wide variety of anatomic sites and clinical scenarios. We report a case arising in a thyroid hyperplastic nodule, only the second case reported in this location. Notably, this is only the fourth case of fibrin-associated large B-cell lymphoma that is not associated with Epstein-Barr virus. We provide a literature review on the clinico-pathological characteristics and outcome of this newly characterized indolent lymphoma type, which has only recently been separated out from the pathologically similar but highly aggressive large B-cell lymphoma associated with chronic inflammation.

Cavity-based lymphomas: challenges and novel concepts. A report of the 2022 EA4HP/SH lymphoma workshop

The 2022 European Association for Haematopathology/Society for Hematopathology lymphoma workshop session on cavity-based lymphomas included sixty-eight cases in seven sections. The disease entities discussed include primary effusion lymphomas (PEL), extracavitary primary effusion lymphomas and confounding entities (ECPEL), HHV8-negative B-lineage lymphomas-effusion based (EBV-negative, EBV-positive, and plasmablastic types), diffuse large B-cell lymphoma associated with chronic inflammation, fibrin-associated diffuse large B-cell lymphoma (FA-DLBCL), breast implant-associated anaplastic large cell lymphoma (BIA-ALCL), and other lymphomas presenting as an effusion. All entities above are discussed; however, three are delved into greater detail given the challenges with classification: ECPEL, HHV8-negative effusion-based lymphomas, and FA-DLBCL. Cases exemplifying the diagnostic difficulty in differentiating ECPEL from HHV8-positive diffuse large B-cell lymphoma and germinotropic lymphoproliferative disorder were discussed. The more recently recognized effusion-based HHV8-negative large B-cell lymphoma is explored, with several cases submitted raising the question if this subset should be carved out as a specific entity, and if so, what should be the refining diagnostic criteria. Case submissions to the FA-DLBCL section yielded one of the largest case series to date, including classic cases, cases furthering the discussion on disease sites and prognosis, as well as novel concepts to be considered in this entity. The 2022 EA4HP/SH workshop cases allowed for further confirmation of the characteristics of some of the more historically accepted cavity-based lymphomas, as well as further inquiry and debate on relatively new or evolving entities.

Visual analysis based on CiteSpace software: a bibliometric study of atrial myxoma

Objective

To use CiteSpace and VOSviewer visual metrology to analyze the research status, frontier hotspots, and trends in research on atrial myxoma.

Methods

The Web of Science core collection database was used to retrieve relevant literature on atrial myxoma from 2001 to 2022. CiteSpace software was used to analyze keywords with a co-occurrence network, co-polymerization class, and burst terms, and a corresponding visual atlas was drawn for analysis.

Results

A total of 893 valid articles were included. The country with the highest number of articles was the United States (n = 186). The organization with the highest number of articles was the Mayo Clinic (n = 15). The author with the highest number of articles was Yuan SM (n = 12). The highest cited author was Reynen K (n = 312). The highest cited journal was Annals of Thoracic Surgery (n = 1,067). The most frequently cited literature was published in the New England Journal of Medicine in 1995, which was cited 233 times. The keywords co-occurrence, copolymerization analysis, and Burst analysis revealed that the main research focuses were surgical methods, case reports, and genetic and molecular level studies on the pathogenesis of myxoma.

Conclusions

This bibliometric analysis revealed that the main research topics and hotspots in atrial myxoma included surgical methods, case reports, genetic and molecular studies.

Large B-Cell Lymphomas in the 5th Edition of the WHO-Classification of Haematolymphoid Neoplasms-Updated Classification and New Concepts

The family/class of the large B-cell lymphomas (LBCL) in the 5th edition of the World Health Organization (WHO) classification of haematolymphoid tumors (WHO-HAEM5) features only a few major changes as compared to the 4th edition. In most entities, there are only subtle changes, many of them only representing some minor modifications in diagnostic terms. Major changes have been made in the diffuse large B-cell lymphomas (DLBCL)/high-grade B-cell lymphomas (HGBL) associated with MYC and BCL2 and/or BCL6 rearrangements. This category now consists of MYC and BCL2 rearranged cases exclusively, while the MYC/BCL6 double hit lymphomas now constitute genetic subtypes of DLBCL, not otherwise specified (NOS) or of HGBL, NOS. Other major changes are the conceptual merger of lymphomas arising in immune-privileged sites and the description of LBCL arising in the setting of immune dysregulation/deficiency. In addition, novel findings concerning underlying biological mechanisms in the pathogenesis of the different entities are provided.