Transcriptional analysis distinguishes breast implant-associated anaplastic large cell lymphoma from other peripheral T-cell lymphomas

A comparison of the International Consensus and 5th WHO classifications of T-cell lymphomas and histiocytic/dendritic cell tumours

Since the publication in 2017 of the revised 4th Edition of the World Health Organization (WHO) classification of haematolymphoid tumours, here referred to as WHO-HAEM4, significant clinicopathological, immunophenotypic and molecular advances have been made in the field of lymphomas, contributing to refining the diagnostic criteria of several diseases, upgrading entities previously defined as provisional and identifying new entities. This process has resulted in two recent classification proposals of lymphoid neoplasms: the International Consensus Classification (ICC) and the 5th edition of the WHO classification (WHO-HAEM5). In this paper, we review and compare the two classifications in terms of diagnostic criteria and entity definition, focusing on T-cell lymphomas and histiocytic/dendritic cell tumours. Moreover, we update the genetic data of the various pathological entities. The main goal is to provide a tool to facilitate the work of the pathologists, haematologists and researchers involved in the diagnosis and treatment of these haematological malignancies.

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.

Establishment and characterization of a novel breast implant-associated anaplastic large cell lymphoma cell line and PDX model (BIA-XR1) with a unique KRAS mutation

Breast implant-associated anaplastic large cell lymphoma (BIA-ALCL) is an uncommon T-cell lymphoma type with distinct clinical, molecular and genetic features. Establishment of BIA-ALCL cell lines and patient-derived xenograft (PDX) models are essential experimental tools to investigate the molecular pathogenesis of the disease. We characterized a novel BIA-ALCL cell line and PDX model, named BIA-XR1, derived from a patient with textured breast implant who developed lymphoma. Next-generation sequencing revealed a STAT3 mutation, commonly detected in BIA-ALCL, and a unique KRAS mutation reported for the first time in this lymphoma type. Both JAK/STAT3 and RAS/MEK/ERK oncogenic pathways were activated in BIA-XR1, which are targetable with clinically available agents.

Study of the Effect of Different Breast Implant Surfaces on Capsule Formation and Host Inflammatory Response in an Animal Model

BACKGROUND

Breast implants are biomaterials eliciting a physiological and mandatory foreign body response.

OBJECTIVES

The authors designed an animal study to investigate the impact of different implant surfaces on the formation of the periprosthetic capsule, the inflammatory response, and the cellular composition.

METHODS

The authors implanted 1 scaled-down version of breast implants by different manufactures on 70 female Sprague Dawley rats. Animals were divided into 5 groups of 14 animals. Group A received a smooth implant (Ra ≈ 0.5 µm) according to the ISO 14607-2018 classification, Group B a smooth implant (Ra ≈ 3.2 µm), Group C a smooth implant (Ra ≈ 5 µm), Group D a macrotextured implant (Ra ≈ 62 µm), and Group E a macrotextured implant (Ra ≈ 75 µm). At 60 days, all animals received a magnetic resonance imaging (MRI), and 35 animals were killed and their capsules sent for histology (capsule thickness, inflammatory infiltrate) and immunohistochemistry analysis (cellular characterization). The remaining animals repeated the MRI at 120 days and were killed following the same protocol.

RESULTS

MRI showed a thinner capsule in the smooth implants (Groups A-C) at 60 days (P < .001) but not at 120 days (P = .039), confirmed with histology both at 60 days (P = .005) and 120 days (P < .001). Smooth implants (Groups A-C) presented a mild inflammatory response at 60 days that was maintained at 120 days and a high M2-Macrophage concentration (anti-inflammatory).

CONCLUSIONS

Our study confirms that smooth implants form a thinner capsule, inferior inflammatory infiltrate, and a cellular composition that indicates a mild host inflammatory response. A new host inflammatory response classification is elaborated classifying breast implants into mild, moderate, and high.

Mature T-cell and NK-cell lymphomas: updates on molecular genetic features

Mature T-cell and NK-cell lymphomas are a heterogeneous group of rare and typically aggressive neoplasms. Diagnosis and subclassification have historically relied primarily on the integration of clinical, histologic, and immunophenotypic features, which often overlap. The widespread application of a variety of genomic techniques in recent years has provided extensive insight into the pathobiology of these diseases, allowing for more precise diagnostic classification, improved prognostication, and development of novel therapies. In this review, we summarize the genomic features of the most common types of mature T-cell and NK-cell lymphomas with a particular focus on the contribution of genomics to biologic insight, classification, risk stratification, and select therapies in the context of the recently published International Consensus and updated World Health Organization classification systems.

Extranodal T- and NK-cell lymphomas

Non-cutaneous extranodal NK/T cell lymphoproliferations constitute a heterogenous group of rare neoplasms, occurring primarily in the gastro-intestinal tract, nasal area, spleen, and liver. Their nomenclature refers to their usual clinical presentation and predilection for specific anatomic sites-i.e. extranodal NK/T-cell lymphoma, nasal-type, hepatosplenic T-cell lymphoma, primary intestinal T-cell lymphomas, indolent lymphoproliferative disorders of the gastrointestinal tract, and breast implant-associated anaplastic large cell lymphoma. Extranodal tissues may also be involved by T-cell leukemias, or other entities usually presenting as nodal diseases. Primary extranodal entities range from indolent to highly aggressive diseases. Here, we will review the clinicopathologic features of the pertinent entities including the recent advances in their molecular and genetic characterization, with an emphasis on the changes introduced in the 2022 International Consensus Classification of lymphoid neoplasms, and highlight the diagnostic criteria helpful to sort out the distinction with potential mimickers.

Clinical recommendations for diagnosis and treatment according to current updated knowledge on BIA-ALCL

Shared strategies and correct information are essential to guide physicians in the management of such an uncommon disease as Breast Implant-Associated Anaplastic Large Cell Lymphoma (BIA-ALCL). A systematic review of the literature was performed to collect the most relevant evidence on BIA-ALCL reported cases. A panel of multidisciplinary experts discussed the scientific evidence on BIA-ALCL, and updated consensus recommendations were developed through the Delphi process. The lastest reported Italian incidence of BIA-ALCL is 3.5 per 100.000 implanted patients (95% CI, 1.36 to 5.78), and the disease counts over 1216 cases worldwide as of June 2022. The most common presentation symptom is a late onset seroma followed by a palpable breast mass. In the event of a suspicious case, ultrasound-guided fine-needle aspiration should be the first step in evaluation, followed by cytologic and immunohistochemical examination. In patients with confirmed diagnosis of BIA-ALCL confined to the capsule, the en-bloc capsulectomy should be performed, followed by immediate autologous reconstruction, while delayed reconstruction applies for disseminate disease or radically unresectable tumor. Nevertheless, a multidisciplinary team approach is essential for the correct management of this pathology.

The International Consensus Classification of Mature Lymphoid Neoplasms: a report from the Clinical Advisory Committee

Since the publication of the Revised European-American Classification of Lymphoid Neoplasms in 1994, subsequent updates of the classification of lymphoid neoplasms have been generated through iterative international efforts to achieve broad consensus among hematopathologists, geneticists, molecular scientists, and clinicians. Significant progress has recently been made in the characterization of malignancies of the immune system, with many new insights provided by genomic studies. They have led to this proposal. We have followed the same process that was successfully used for the third and fourth editions of the World Health Organization Classification of Hematologic Neoplasms. The definition, recommended studies, and criteria for the diagnosis of many entities have been extensively refined. Some categories considered provisional have now been upgraded to definite entities. Terminology for some diseases has been revised to adapt nomenclature to the current knowledge of their biology, but these modifications have been restricted to well-justified situations. Major findings from recent genomic studies have impacted the conceptual framework and diagnostic criteria for many disease entities. These changes will have an impact on optimal clinical management. The conclusions of this work are summarized in this report as the proposed International Consensus Classification of mature lymphoid, histiocytic, and dendritic cell tumors.

Mutations Affecting Genes in the Proximal T-Cell Receptor Signaling Pathway in Peripheral T-Cell Lymphoma

Simple Summary

The advent of next-generation sequencing (NGS) has allowed rapid advances in genomic studies on the pathogenesis and biology of peripheral T-cell lymphoma (PTCL). Recurrent mutations and fusions in genes related to the proximal TCR signaling pathway have been identified and show an important pathogenic role in PTCL. In this review, we summarize the genomic alterations in TCR signaling identified in different subgroups of PTCL patients and the functional impact of these alterations on TCR signaling and downstream pathways. We also discuss novel agents that could target TCR-related mutations and may hold promise for improving the treatment of PTCL.

Abstract

Peripheral T-cell lymphoma (PTCL) comprises a heterogeneous group of mature T-cell malignancies. Recurrent activating mutations and fusions in genes related to the proximal TCR signaling pathway have been identified in preclinical and clinical studies. This review summarizes the genetic alterations affecting proximal TCR signaling identified from different subgroups of PTCL and the functional impact on TCR signaling and downstream pathways. These genetic abnormalities include mostly missense mutations, occasional indels, and gene fusions involving CD28, CARD11, the GTPase RHOA, the guanine nucleotide exchange factor VAV1, and kinases including FYN, ITK, PLCG1, PKCB, and PI3K subunits. Most of these aberrations are activating mutations that can potentially be targeted by inhibitors, some of which are being tested in clinical trials that are briefly outlined in this review. Finally, we focus on the molecular pathology of recently identified subgroups of PTCL-NOS and highlight the unique genetic profiles associated with PTCL-GATA3.

A South African Breast Implant-Associated Anaplastic Large Cell Lymphoma: Clinical Presentation and Six-Year Follow-Up

Breast augmentation is the most common surgical procedure for women globally, with 1,795,551 cases performed in 2019. Breast implant-associated anaplastic large cell lymphoma (BIA-ALCL) is highly uncommon, with 733 reported cases as of January 2020. In South Africa, there are less than 4000 breast augmentation surgeries annually. This case presents the first case report documentation of a South African woman diagnosed with BIA-ALCL. The patient was a 61-year-old woman who consulted the Breast Care Centre of Excellence in Johannesburg in 2015. She had a prior history of bilateral augmentation mammoplasty with subsequent implant exchange. The patient presented with periprosthetic fluid with a mass-like enhancement on the left breast. Aspiration of the mass-like fluid was positive for CD45, CD30, and CD68 and negative for CD20 and ALK-1, indicative of BIA-ALCL. Surgical treatment included bilateral explantation, complete capsulectomies, and bilateral mastopexy. Macroscopic examination of the left breast capsulectomy demonstrated fibrous connective tissue. The histological examination of the tumor showed extensive areas of broad coagulative necrosis with foamy histiocytes. Immunohistochemistry examination of this tumor showed CD3-, CD20-, and ALK-1-negative and CD30- and CD68-positive stains. PCR analysis for T-cell clonality showed monoclonal T-cell expansion. These findings confirm the presence of BIA-ALCL. The patient recovered well after surgery and did not require adjuvant therapy. A patient with a confirmed diagnosis of BIA-ALCL was successfully treated with explantation and complete capsulectomy. She was followed up regularly for six years, and the patient remains well and in remission.

2022 Practice Recommendation Updates From the World Consensus Conference on BIA-ALCL

BACKGROUND

Laboratory and clinical research on breast implant-associated anaplastic large cell lymphoma (BIA-ALCL) is rapidly evolving. Changes in standard of care and insights into best practice were recently presented at the 3rd World Consensus Conference on BIA-ALCL.

OBJECTIVES

The authors sought to provide practice recommendations from a consensus of experts, supplemented with a literature review regarding epidemiology, etiology, pathogenesis, diagnosis, treatment, socio-psychological aspects, and international authority guidance.

METHODS

A literature search of all manuscripts between 1997 and August 2021 for the above areas of BIA-ALCL was conducted with the PubMed database. Manuscripts in different languages, on non-human subjects, and/or discussing conditions separate from BIA-ALCL were excluded. The study was conducted employing the Delphi process, gathering 18 experts panelists and utilizing email-based questionnaires to record the level of agreement with each statement by applying a 5-point Likert Scale. Median response, interquartile range, and comments were employed to accept, reject, or revise each statement.

RESULTS

The literature search initially yielded 764 manuscripts, of which 405 were discarded. From the remaining 359, only 218 were included in the review and utilized to prepare 36 statements subdivided into 5 sections. After 1 round, panelists agreed on all criteria.

CONCLUSIONS

BIA-ALCL is uncommon and still largely underreported. Mandatory implant registries and actions by regulatory authorities are needed to better understand disease epidemiology and address initial lymphomagenesis and progression. Deviation from current diagnosis and treatment protocols can lead to disease recurrence, and research on breast implant risk factors provide insight to etiology.

LEVEL OF EVIDENCE: 4

Integrated analysis of 14 lymphoma datasets revealed high expression of CXCL14 promotes cell migration in mantle cell lymphoma

Lymphoma is accompanied by the impairment of multiple immune functions. Cytokines play an important role in a variety of immune-related functions and affect the tumor microenvironment. However, the exact regulatory mechanisms between them remain unclear. This study aimed to explore the cytokines expression and function in Hodgkin's lymphoma (HL), diffuse large B-cell lymphoma (DLBCL), and mantle cell lymphoma (MCL). We performed a transcriptome integration analysis of 14 lymphoma datasets including 240 Hodgkin's lymphoma, 891 diffuse large B-cell lymphoma, 216 mantle cell lymphoma, and 64 health samples. The results showed that multiple immune functions and signal pathway damage were shared by all three types of lymphoma, and these functions were related to cytokines. Furthermore, through co-expression network and functional interaction network analysis, we identified CXCL14 as a key regulator and it affects cell chemotaxis and migration functions. The functional experiment showed that CXCL14 knockdown inhibited cell migration in MCL cell lines. This study suggested that high expression of CXCL14 may aggravate MCL via promoting cell migration. Our findings provide novel insights into the biology of this disease and would be helpful for the pathogenesis study and drug discovery of lymphomas.

Invasive stage III breast implant-associated anaplastic large cell lymphoma successfully treated with incomplete resection

A woman with history of bilateral breast augmentation 15 years prior presented with right breast swelling, peri-implant effusion and a palpable inferomedial mass. Effusion aspiration demonstrated pleiomorphic cells consistent with breast implant-associated anaplastic large cell lymphoma (BIA-ALCL). Further diagnostic studies confirmed stage III disease with a 4.7 cm right breast mass and fluorodeoxyglucose uptake in an internal mammary chain lymph node. The patient underwent surgery with incomplete resection due to invasion of the chest wall followed by chemotherapy and radiation therapy. BIA-ALCL typically presents as an indolent effusion, however advanced disease carries a worse prognosis. This case highlights successful treatment without recurrence past the one-year mark as well as the need for multidisciplinary management when dealing with advanced disease.

CD30+ Lymphoproliferative Disorders as Potential Candidates for CD30-Targeted Therapies

CONTEXT.—

In the early 1980s, a monoclonal antibody termed Ki-1 was developed against a cell line derived from a patient with Hodgkin lymphoma. This antibody detected a limited number of benign activated lymphocytes in lymphoid tissue, whereas in Hodgkin lymphoma it appeared to be nearly specific for Reed-Sternberg cells and their mononuclear variants. Subsequent studies showed that Ki-1 expression defined a new type of lymphoma that was later designated anaplastic large cell lymphoma with or without anaplastic large cell kinase expression/translocation. In the past 30 years, numerous new lymphoma entities have been defined, many of which are variably positive for CD30. Many virally transformed lymphoproliferative disorders are also frequently positive for CD30.

OBJECTIVE.—

To illustrate the broad spectrum of CD30+ hematologic malignancies and to provide an update of CD30-targeted therapies.

DATA SOURCES.—

Personal experiences and published works in PubMed.

CONCLUSIONS.—

Because of its low expression in normal tissue, CD30 was studied as a therapeutic target for many years. However, the first functional humanized antibody against CD30 was developed only about 10 years ago. Brentuximab vedotin is a humanized anti-CD30 antibody linked to a cytotoxin, and was approved by the US Food and Drug Administration in 2012 for treating refractory Hodgkin lymphoma and anaplastic large cell lymphoma. Since then, the list of Food and Drug Administration-approved CD30-targeted hematologic malignancies has grown. Recently, the therapies using tumor antigen-specific chimeric antigen receptor T cells targeting CD30 have incited a great deal of enthusiasm and are studied in clinical trials.

Genetic profiling and biomarkers in peripheral T-cell lymphomas: current role in the diagnostic work-up

Peripheral T-cell lymphomas are a heterogeneous, and usually aggressive, group of mature T-cell neoplasms with overlapping clinical, morphologic and immunologic features. A large subset of these neoplasms remains unclassifiable with current diagnostic methods ("not otherwise specified"). Genetic profiling and other molecular tools have emerged as widely applied and transformative technologies for discerning the biology of lymphomas and other hematopoietic neoplasms. Although the application of these technologies to peripheral T-cell lymphomas has lagged behind B-cell lymphomas and other cancers, molecular profiling has provided novel prognostic and diagnostic markers as well as an opportunity to understand the biologic mechanisms involved in the pathogenesis of these neoplasms. Some biomarkers are more prevalent in specific T-cell lymphoma subsets and are being used currently in the diagnosis and/or risk stratification of patients with peripheral T-cell lymphomas. Other biomarkers, while promising, need to be validated in larger clinical studies. In this review, we present a summary of our current understanding of the molecular profiles of the major types of peripheral T-cell lymphoma. We particularly focus on the use of biomarkers, including those that can be detected by conventional immunohistochemical studies and those that contribute to the diagnosis, classification, or risk stratification of these neoplasms.

Current Progress in Breast Implant-Associated Anaplastic Large Cell Lymphoma

Breast implant-associated anaplastic large-cell lymphoma (BIA-ALCL) is an uncommon type of T-cell lymphoma. Although with a low incidence, the epidemiological data raised the biosafety and health concerns of breast reconstruction and breast augmentation for BIA-ALCL. Emerging evidence confirms that genetic features, bacterial contamination, chronic inflammation, and textured breast implant are the relevant factors leading to the development of BIA-ALCL. Almost all reported cases with a medical history involve breast implants with a textured surface, which reflects the role of implant surface characteristics in BIA-ALCL. With this review, we expect to highlight the most significant features on etiology, pathogenesis, diagnosis, and therapy of BIA-ALCL, as well as we review the physical characteristics of breast implants and their potential pathogenic effect and hopefully provide a foundation for optimal choice of type of implant with minimal morbidity.

RNA Sequencing of Primary Cutaneous and Breast-Implant Associated Anaplastic Large Cell Lymphomas Reveals Infrequent Fusion Transcripts and Upregulation of PI3K/AKT Signaling via Neurotrophin Pathway Genes

Simple Summary

Cutaneous and breast implant-associated anaplastic large-cell lymphomas are usually localized neoplasms with an indolent clinical course compared to systemic ALCL. However comparative analyses of the molecular features of these two entities have not yet been reported. We performed targeted RNA sequencing, which revealed that fusion transcripts, although infrequent, might represent additional pathogenetic events in both diseases. We also found that these entities display upregulation of the PI3K/Akt pathway and show enrichment in genes of the neurotrophin signaling pathway. These findings advance our knowledge regarding the pathobiology of cALCL and BI-ALCL and point to additional therapeutic targets.

Abstract

Cutaneous and breast implant-associated anaplastic large-cell lymphomas (cALCLs and BI-ALCLs) are two localized forms of peripheral T-cell lymphomas (PTCLs) that are recognized as distinct entities within the family of ALCL. JAK-STAT signaling is a common feature of all ALCL subtypes, whereas DUSP22/IRF4, TP63 and TYK gene rearrangements have been reported in a proportion of ALK-negative sALCLs and cALCLs. Both cALCLs and BI-ALCLs differ in their gene expression profiles compared to PTCLs; however, a direct comparison of the genomic alterations and transcriptomes of these two entities is lacking. By performing RNA sequencing of 1385 genes (TruSight RNA Pan-Cancer, Illumina) in 12 cALCLs, 10 BI-ALCLs and two anaplastic lymphoma kinase (ALK)-positive sALCLs, we identified the previously reported TYK2-NPM1 fusion in 1 cALCL (1/12, 8%), and four new intrachromosomal gene fusions in 2 BI-ALCLs (2/10, 20%) involving genes on chromosome 1 (EPS15-GNG12 and ARNT-GOLPH3L) and on chromosome 17 (MYO18A-GIT1 and NF1-GOSR1). One of the two BI-ALCL samples showed a complex karyotype, raising the possibility that genomic instability may be responsible for intra-chromosomal fusions in BI-ALCL. Moreover, transcriptional analysis revealed similar upregulation of the PI3K/Akt pathway, associated with enrichment in the expression of neurotrophin signaling genes, which was more conspicuous in BI-ALCL, as well as differences, i.e., over-expression of genes involved in the RNA polymerase II transcription program in BI-ALCL and of the RNA splicing/processing program in cALCL.

An Update on the Current Genomic Landscape of Breast Implant-Associated Anaplastic Large Cell Lymphoma

Simple Summary

Breast implant-associated lymphoma is a unique entity that arises in the setting of breast prostheses due to a complex interplay of external and internal factors. Understanding of the mechanisms of pathogenesis is yet to be fully elucidated but recurrent mutations in signalling pathways, tumour suppressors and epigenetic regulators have been reported. This article summarises the key studies to date that have described these genetic aberrancies, which have provided an insight into potential pathways to lymphogenesis.

Abstract

Breast implant-associated lymphoma (BIA-ALCL) is a rare subtype of anaplastic large-cell lymphoma associated with breast prostheses. Most patients present with a localised periprosthetic effusion and are managed with removal of the implant and surrounding capsule. Less commonly, the lymphoma can form a mass associated with the capsule and rarely can present with disseminated disease. Recent series characterising the genomic landscape of BIA-ALCL have led to insights into the mechanisms of lymphomagenesis. Constitutive JAK/STAT pathway activation has emerged as a likely key component while, more recently, aberrancies in epigenetic regulators have been reported. This review describes the genomic characterisation reported to date and the insight these findings have provided into this rare entity.

Metabolic Switch and Cytotoxic Effect of Metformin on Burkitt Lymphoma

Altered cellular energetic metabolism has recently emerged as important feature of neoplastic cells. Indeed, interfering with cancer cell metabolism might represent a suitable therapeutic strategy. In this study, we aimed to assess glucose metabolism activation in human lymphomas and evaluate how metformin can exert its action on lymphoma cells. We studied a large series of human lymphomas (N = 252) and an in vitro model of Burkitt lymphoma (BL) cells. We combined molecular biology techniques, including global gene expression profiling (GEP) analysis, quantitative PCR (qPCR) and Western blotting, and biochemical assays, aimed to assess pentose phosphate pathway, tricarboxylic acid (TCA) cycle, and aerobic glycolysis rates. We found that glucose metabolism is overall enhanced in most lymphoma subtypes, based on gene expression profiling (GEP), with general shift to aerobic glycolysis. By contrast, normal B cells only showed an overall increase in glucose usage during germinal center transition. Interestingly, not only highly proliferating aggressive lymphomas but also indolent ones, like marginal zone lymphomas, showed the phenomenon. Consistently, genes involved in glycolysis were confirmed to be overexpressed in BL cells by qPCR. Biochemical assays showed that while aerobic glycolysis is increased, TCA cycle is reduced. Finally, we showed that metformin can induce cell death in BL cells by stressing cellular metabolism through the induction of GLUT1, PKM2, and LDHA. In conclusion, we unveiled glucose metabolism abnormalities in human lymphomas and characterized the mechanism of action of metformin in Burkitt lymphoma model.

Update on the Classification and Diagnostic Approaches of Mature T-Cell Lymphomas

CONTEXT.—

In the 2017 revised World Health Organization classification of tumors of hematopoietic and lymphoid tissues, some mature T-cell lymphomas are reclassified and a few new provisional entities are established based on new data from clinical and laboratory studies. T follicular helper cell lymphoma is identified by T follicular helper cell markers. Anaplastic large cell lymphoma, ALK negative, is a better-defined entity based on genetic abnormalities, and breast implant-associated anaplastic large cell lymphoma is recognized as a provisional entity. The gastrointestinal T-cell lymphomas are reclassified, with addition of a new provisional entity, indolent T-cell lymphoproliferative disorder of the gastrointestinal tract, characterized by an indolent clinical course.

OBJECTIVE.—

To review the diagnostic approaches of reclassified and newly established entities of mature T-cell lymphomas, focusing on significant immunophenotypic features and molecular genetic abnormalities. Relevant new discoveries after the publication of the 2017 World Health Organization classification are included.

DATA SOURCES.—

Information from the literature most relevant to 2017 World Health Organization revised classification and publications after 2016.

CONCLUSIONS.—

Incorporating clinical, morphologic, and immunophenotypic features usually provides sufficient evidence to reach a preliminary diagnosis of mature T-cell lymphoma. Molecular genetic studies can be very helpful for the final diagnosis and classification, especially in challenging cases. Some molecular genetic features have been found in breast implant-associated anaplastic large cell lymphoma, distinct from anaplastic large cell lymphoma, ALK negative. Immunohistochemical staining of 4 markers may enable further subtyping of peripheral T-cell lymphomas.

Cytokines, Genetic Lesions and Signaling Pathways in Anaplastic Large Cell Lymphomas

ALCL is a tumor of activated T cells and possibly innate lymphoid cells with several subtypes according to clinical presentation and genetic lesions. On one hand, the expression of transcription factors and cytokine receptors triggers signaling pathways. On the other hand, ALCL tumor cells also produce many proteins including chemokines, cytokines and growth factors that affect patient symptoms. Examples are accumulation of granulocytes stimulated by IL-8, IL-17, IL-9 and IL-13; epidermal hyperplasia and psoriasis-like skin lesions due to IL-22; and fever and weight loss in response to IL-6 and IFN-γ. In this review, we focus on the biology of the main ALCL subtypes as the identification of signaling pathways and ALCL-derived cytokines offers opportunities for targeted therapies.

The management of breast implant-associated anaplastic large cell lymphoma in the setting of pregnancy: seeking for clinical practice guidelines

Breast implant-associated anaplastic large cell lymphoma (BIA-ALCL) is a recently described form of T-cell non-Hodgkin lymphoma now formally recognized by the World Health Organization classification of lymphoid neoplasms. The aim of this paper is to report the first case of BIA-ALCL diagnosed in a pregnant patient. It is well known that BIA-ALCL appears as an indolent lymphoma with a good prognosis when diag-nosed at early stages and clinical guidelines for its management have been clearly published. Nevertheless, they lack a standardized approach for BIA-ALCL during pregnancy. With limited experience in our case, treatment has been safely postponed after term without affecting patient’s overall prognosis and without fetal complication. The fact that the disease was diagnosed at an early stage (stage I) undoubtedly influenced the course of treatment. A multidisciplinary approach weighing the risks and benefits of treatment is of paramount importance in order to ensure the best possible outcome for both the mother and her child and clinical update guidelines should be issued.

Chronic T cell receptor stimulation unmasks NK receptor signaling in peripheral T cell lymphomas via epigenetic reprogramming

Peripheral T cell lymphomas (PTCLs) represent a significant unmet medical need with dismal clinical outcomes. The T cell receptor (TCR) is emerging as a key driver of T lymphocyte transformation. However, the role of chronic TCR activation in lymphomagenesis and in lymphoma cell survival is still poorly understood. Using a mouse model, we report that chronic TCR stimulation drove T cell lymphomagenesis, whereas TCR signaling did not contribute to PTCL survival. The combination of kinome, transcriptome, and epigenome analyses of mouse PTCLs revealed a NK cell-like reprogramming of PTCL cells with expression of NK receptors (NKRs) and downstream signaling molecules such as Tyrobp and SYK. Activating NKRs were functional in PTCLs and dependent on SYK activity. In vivo blockade of NKR signaling prolonged mouse survival, demonstrating the addiction of PTCLs to NKRs and downstream SYK/mTOR activity for their survival. We studied a large collection of human primary samples and identified several PTCLs recapitulating the phenotype described in this model by their expression of SYK and the NKR, suggesting a similar mechanism of lymphomagenesis and establishing a rationale for clinical studies targeting such molecules.

Molecular profiling reveals a hypoxia signature in breast implant-associated anaplastic large cell lymphoma

Breast implant-associated anaplastic large cell lymphoma (BIAALCL) is a recently characterized T-cell malignancy that has raised significant patient safety concerns and led to worldwide impact on the implants used and clinical management of patients undergoing reconstructive or cosmetic breast surgery. Molecular signatures distinguishing BIA-ALCL from other anaplastic large cell lymphomas have not been fully elucidated and classification of BIA-ALCL as a World Health Organization entity remains provisional. We performed RNA sequencing and gene set enrichment analysis comparing BIA-ALCL to non-BIAALCL and identified dramatic upregulation of hypoxia signaling genes including the hypoxia-associated biomarker CA9 (carbonic anyhydrase- 9). Immunohistochemistry validated CA9 expression in all BIA-ALCL, with only minimal expression in non-BIA-ALCL. Growth induction in BIA-ALCL-derived cell lines cultured under hypoxic conditions was proportional to upregulation of CA9 expression, and RNA sequencing demonstrated induction of the same gene signature observed in BIAALCL tissue samples compared to non-BIA-ALCL. CA9 silencing blocked hypoxia-induced BIA-ALCL cell growth and cell cycle-associated gene expression, whereas CA9 overexpression in BIA-ALCL cells promoted growth in a xenograft mouse model. Furthermore, CA9 was secreted into BIA-ALCL cell line supernatants and was markedly elevated in human BIA-ALCL seroma samples. Finally, serum CA9 concentrations in mice bearing BIA-ALCL xenografts were significantly elevated compared to those in control serum. Together, these findings characterize BIA-ALCL as a hypoxia-associated neoplasm, likely attributable to the unique microenvironment in which it arises. These data support classification of BIA-ALCL as a distinct entity and uncover opportunities for investigating hypoxia-related proteins such as CA9 as novel biomarkers and therapeutic targets in this disease.

The State of the Art about Etiopathogenetic Models on Breast Implant Associated-Anaplastic Large Cell Lymphoma (BIA-ALCL): A Narrative Review

Background: Breast-implant-associated anaplastic large cell lymphoma is a rare malignancy linked to texturized breast implants. Although many researchers focus on its etiopathogenesis, this topic is affected by a lack of evidence. Materials and Methods: A literature review about BIA-ALCL was made. Results and conclusions: Although the incidence is reported between 1:355–1:30,000, there is great attention to BIA-ALCL. The incidence is uncertain due to many reasons. It may well be lower, due to inclusion in multiple databases as pointed out by the FDA and undiagnosed cases. The role of chronic inflammation, bacterial contamination, and mechanical forces was discussed. Clarification is needed to understand the mechanisms underlying the progression of alterations and mutations for BIA-ALCL; new molecular analysis and pathogenetic models should be investigated.

Breast Implant-Associated Anaplastic Large Cell Lymphoma: Defining Future Research Priorities

Breast implant-associated anaplastic large cell lymphoma (BIA-ALCL) is an emerging cancer of the immune system that is exclusively associated with textured-surface breast implants. This clinical review provides an update on the diagnosis and management of BIA-ALCL with an emphasis on major advances. The epidemiology and pathophysiology of the disease are also reviewed, focusing on current paradigm shifts and highlighting current controversies related to disease classification and risk mitigation. Finally, the authors conclude by discussing medicolegal and ethical issues surrounding BIA-ALCL while establishing a future basic science and clinical research agenda that is central to improving patient safety.

Cellular and Molecular Mechanisms of Breast Implant-Associated Anaplastic Large Cell Lymphoma

SUMMARY

Breast implant-associated anaplastic large cell lymphoma (BIA-ALCL) is an emerging and highly treatable cancer of the immune system that can form around textured-surface breast implants. Although the underlying cause has yet to be elucidated, an emerging theme-linking pathogenesis to a chronic inflammatory state-continues to dominate the current literature. Specifically, the combination of increasing mutation burden and chronic inflammation leads to aberrant T-cell clonal expansion. However, the impetus remains largely unknown. Proposed mechanisms include a lipopolysaccharide endotoxin response, oncogenic transformation related to viral infection, associated trauma to the breast pocket, particulate matter digestion by capsular macrophages, chronic allergic inflammation, and genetic susceptibility. The Janus kinase-signal transducer and activator of transcription 3 (JAK-STAT3) pathway is a major signaling pathway that regulates a variety of intracellular growth and survival processes. Constitutive activation of JAK-STAT3 has been implicated in several malignancies, including lymphomas, and has recently been identified as a potential key mediator in BIA-ALCL. The purpose of this article is to review the cellular and molecular mechanisms of BIA-ALCL with a focus on the role of oncogenic JAK-STAT3 signaling in BIA-ALCL tumorigenesis and progression. Selected experimental work from the authors' group on aberrant JAK-STAT3 signaling in BIA-ALCL is also included. The authors discuss how an inflammatory microenvironment may facilitate malignant transformation through the JAK-STAT3 pathway-highlighting its potential mechanistic role. The authors' hope is that further investigation of this signaling pathway will reveal avenues for using JAK-STAT3 signaling as a prognostic indicator and novel therapeutic target in the case of advanced disease.

Analysis of the Molecular Signature of Breast Implant-Associated Anaplastic Large Cell Lymphoma in an Asian Patient

Breast implant-associated anaplastic large cell lymphoma (BIA-ALCL)—a new category of anaplastic large cell lymphoma associated with textured breast implants—has a distinct variation in incidence and is especially rare in Asia. We report the first case of BIA-ALCL in Korea and present its histological and genetic characteristics. A 44-year-old female patient presented with a typical clinical course and symptoms, including breast augmentation with textured breast implants, late-onset peri-implant effusion, and CD30⁺ALK⁻ histology, followed by bilateral implant removal and total capsulectomy. For histological analysis, we performed immunohistochemistry of the bilateral breast capsules. For transcriptome analysis, we identified highly upregulated gene sets employing RNA-sequencing and characterized the lymphoma immune cell components. In the lymphoma-associated capsule, CD30⁺ cells infiltrated not only the lymphoma lesion but also the peritumoral lesion. The morphologies of the myofibroblasts and vessels in the peritumoral lesion were similar to those in the tumoral lesion. We observed strong activation of the JAK/STAT3 pathway and expression of programmed death ligand-1 in the lymphoma. Unlike the molecular profiles of BIA-ALCL samples from Caucasian patients—all of which contained activated CD4⁺ T cells—the Asian patient’s profile was characterized by more abundant CD8⁺ T cells. This study contributes to a better understanding of the pathogenesis and molecular mechanisms of BIA-ALCL in Asian patients that will ultimately facilitate the development of clinical therapies.

Level of Evidence: 5

Breast Implant-Associated Anaplastic Large Cell Lymphoma: A Clinical Update

ABSTRACT

Breast implant-associated anaplastic large cell lymphoma (BIA-ALCL) is a recently recognized malignancy of T-lymphocytes that is linked to certain types of textured breast implants. Although rare, the increasing awareness of the disease is resulting in more case reports and heightened anxiety in patients with textured breast implants. This review aims to summarize the available BIA-ALCL data, including the existing theories of etiopathogenesis, the diagnostic work-up for BIA-ALCL patients, BIA-ALCL treatment recommendations, the epidemiologic challenges, and the current opinions surrounding the use of textured breast implants.

Breast Implant-associated Anaplastic Large Cell Lymphoma: An Evidence-based Systematic Review

OBJECTIVE

This evidence-based systematic review synthesizes and critically appraises current clinical recommendations and advances in the diagnosis and treatment of BIA-ALCL. This review also aims to broaden physician awareness across diverse specialties, particularly among general practitioners, breast surgeons, surgical oncologists, and other clinicians who may encounter patients with breast implants in their practice.

BACKGROUND

BIA-ALCL is an emerging and treatable immune cell cancer definitively linked to textured-surface breast implants. Although the National Comprehensive Cancer Network (NCCN) consensus guidelines and other clinical recommendations have been established, the evidence supporting these guidelines has not been systematically studied. The purpose of this evidence-based systematic review is to synthesize and critically appraise current clinical guidelines and recommendations while highlighting advances in diagnosis and treatment and raising awareness for this emerging disease.

METHODS

This evidence-based systematic review evaluated primary research studies focusing on the diagnosis and treatment of BIA-ALCL that were published in PubMed, Google Scholar, and other scientific databases through March 2020.

RESULTS AND CONCLUSIONS

The clinical knowledge of BIA-ALCL has evolved rapidly over the last several years with major advances in diagnosis and treatment, including en bloc resection as the standard of care. Despite a limited number of high-quality clinical studies comprised mainly of Level III and Level V evidence, current evidence aligns with established NCCN consensus guidelines. When diagnosed and treated in accordance with NCCN guidelines, BIA-ALCL carries an excellent prognosis.

Etiology of Breast Implant-Associated Anaplastic Large Cell Lymphoma (BIA-ALCL): Current Directions in Research

Simple Summary

The first report of breast implant-associated anaplastic large cell lymphoma (BIA-ALCL) was in 1997. Although BIA-ALCL develops around breast implants, it is considered a cancer of the immune system and not a cancer of the breast ducts or lobules. Nearly all confirmed cases to date have been associated with textured surface (versus smooth surface) breast implants. As physicians have become more aware of BIA-ALCL, so has the number of reported cases, although the number of cases remains low. In most instances, patients have an excellent prognosis following removal of the breast implant and its surrounding fibrous capsule. Many theories on factors that trigger the development of BIA-ALCL, such as the presence of bacteria, have been proposed. However, the sequence(s) of events that follow the initial triggering event(s) have not been fully determined. This article summarizes the current scientific knowledge on the development of BIA-ALCL.

Abstract

Breast implant-associated anaplastic large cell lymphoma (BIA-ALCL) is a CD30-positive, anaplastic lymphoma kinase-negative T-cell lymphoma. Where implant history is known, all confirmed cases to date have occurred in patients with exposure to textured implants. There is a spectrum of disease presentation, with the most common occurring as a seroma with an indolent course. A less common presentation occurs as locally advanced or, rarely, as metastatic disease. Here we review the immunological characteristics of BIA-ALCL and potential triggers leading to its development. BIA-ALCL occurs in an inflammatory microenvironment with significant lymphocyte and plasma cell infiltration and a prominent Th1/Th17 phenotype in advanced disease. Genetic lesions affecting the JAK/STAT signaling pathway are commonly present. Proposed triggers for the development of malignancy include mechanical friction, silicone implant shell particulates, silicone leachables, and bacteria. Of these, the bacterial hypothesis has received significant attention, supported by a plausible biologic model. In this model, bacteria form an adherent biofilm in the favorable environment of the textured implant surface, producing a bacterial load that elicits a chronic inflammatory response. Bacterial antigens, primarily of Gram-negative origin, may trigger innate immunity and induce T-cell proliferation with subsequent malignant transformation in genetically susceptible individuals. Although much remains to be elucidated regarding the multifactorial origins of BIA-ALCL, future research should focus on prevention and treatment strategies, recognizing susceptible populations, and whether decreasing the risk of BIA-ALCL is possible.

Chromosome 20 loss is characteristic of breast implant-associated anaplastic large cell lymphoma

Breast implant-associated anaplastic large cell lymphoma (BIA-ALCL) is a very rare type of T-cell lymphoma that is uniquely caused by a single environmental stimulus. Here, we present a comprehensive genetic analysis of a relatively large series of BIA-ALCL (n = 29), for which genome-wide chromosomal copy number aberrations (CNAs) and mutational profiles for a subset (n = 7) were determined. For comparison, CNAs for anaplastic lymphoma kinase (ALK)- nodal anaplastic large cell lymphomas (ALCLs; n = 24) were obtained. CNAs were detected in 94% of BIA-ALCLs, with losses at chromosome 20q13.13 in 66% of the samples. Loss of 20q13.13 is characteristic of BIA-ALCL compared with other classes of ALCL, such as primary cutaneous ALCL and systemic type ALK+ and ALK- ALCL. Mutational patterns confirm that the interleukin-6-JAK1-STAT3 pathway is deregulated. Although this is commonly observed across various types of T-cell lymphomas, the extent of deregulation is significantly higher in BIA-ALCL, as indicated by phosphorylated STAT3 immunohistochemistry. The characteristic loss of chromosome 20 in BIA-ALCL provides further justification to recognize BIA-ALCL as a separate disease entity. Moreover, CNA analysis may serve as a parameter for future diagnostic assays for women with breast implants to distinguish seroma caused by BIA-ALCL from other causes of seroma accumulation, such as infection or trauma.

A Cautionary Tale and Update on Breast Implant-Associated Anaplastic Large Cell Lymphoma (BIA-ALCL)

Breast implant-associated anaplastic large T-cell lymphoma (BIA-ALCL) was first recognized by the World Health Organization in 2016. The total number of cases worldwide continues to increase, with >800 cases confirmed through a combination of Food and Drug Administration data, verified reports, and registries. To date, 33 deaths have been reported. Typical presentation includes a late seroma containing monoclonal T cells that are CD30 positive and anaplastic lymphoma kinase negative. We present a review of the current literature and report on 3 cases of BIA-ALCL at our institution, which serve to illustrate our approach to diagnosis and management of this disease. In 2 cases, the diagnosis of BIA-ALCL was not initially confirmed due to an incomplete workup but was recognized upon explantation. The seroma fluid was sent for flow cytometry. Initially, the cells were reported as morphologically suspicious for malignancy with phenotypically normal T cells based on standard CD3+ T-cell gating. Subsequent cytology specimens were reported as consistent with recurrent adenocarcinoma. However, upon regating of flow-cytometry data, a population of CD30+, CD3- T cells was noted and the diagnosis of BIA-ALCL was confirmed by immunohistochemical stains of the excised breast capsule specimen. Given the increasing incidence of this disease, as plastic surgeons we must stay informed to order the correct workup to avoid misdiagnosis and be prepared to appropriately refer affected patients to centers with multidisciplinary teams experienced in the management of BIA-ALCL.

LEVEL OF EVIDENCE: 4

IL-10, IL-13, Eotaxin and IL-10/IL-6 ratio distinguish breast implant-associated anaplastic large-cell lymphoma from all types of benign late seromas

Breast implant-associated anaplastic large-cell lymphoma (BI-ALCL) is an uncommon peripheral T cell lymphoma usually presenting as a delayed peri-implant effusion. Chronic inflammation elicited by the implant has been implicated in its pathogenesis. Infection or implant rupture may also be responsible for late seromas. Cytomorphological examination coupled with CD30 immunostaining and eventual T-cell clonality assessment are essential for BI-ALCL diagnosis. However, some benign effusions may also contain an oligo/monoclonal expansion of CD30 + cells that can make the diagnosis challenging. Since cytokines are key mediators of inflammation, we applied a multiplexed immuno-based assay to BI-ALCL seromas and to different types of reactive seromas to look for a potential diagnostic BI-ALCL-associated cytokine profile. We found that BI-ALCL is characterized by a Th2-type cytokine milieu associated with significant high levels of IL-10, IL-13 and Eotaxin which discriminate BI-ALCL from all types of reactive seroma. Moreover, we found a cutoff of IL10/IL-6 ratio of 0.104 is associated with specificity of 100% and sensitivity of 83% in recognizing BI-ALCL effusions. This study identifies promising biomarkers for initial screening of late seromas that can facilitate early diagnosis of BI-ALCL.

A Novel JAK1 Mutant Breast Implant-Associated Anaplastic Large Cell Lymphoma Patient-Derived Xenograft Fostering Pre-Clinical Discoveries

Breast implant-associated lymphoma (BIA-ALCL) has recently been recognized as an independent peripheral T-cell lymphoma (PTCL) entity. In this study, we generated the first BIA-ALCL patient-derived tumor xenograft (PDTX) model (IL89) and a matching continuous cell line (IL89_CL#3488) to discover potential vulnerabilities and druggable targets. We characterized IL89 and IL89_CL#3488, both phenotypically and genotypically, and demonstrated that they closely resemble the matching human primary lymphoma. The tumor content underwent significant enrichment along passages, as confirmed by the increased variant allele frequency (VAF) of mutations. Known aberrations (JAK1 and KMT2C) were identified, together with novel hits, including PDGFB, PDGFRA, and SETBP1. A deep sequencing approach allowed the detection of mutations below the Whole Exome Sequencing (WES) sensitivity threshold, including JAK1G1097D, in the primary sample. RNA sequencing confirmed the expression of a signature of differentially expressed genes in BIA-ALCL. Next, we tested IL89’s sensitivity to the JAK inhibitor ruxolitinib and observed a potent anti-tumor effect, both in vitro and in vivo. We also implemented a high-throughput drug screening approach to identify compounds associated with increased responses in the presence of ruxolitinib. In conclusion, these new IL89 BIA-ALCL models closely recapitulate the primary correspondent lymphoma and represent an informative platform for dissecting the molecular features of BIA-ALCL and performing pre-clinical drug discovery studies, fostering the development of new precision medicine approaches.

Breast implant-associated anaplastic large cell lymphoma: A comprehensive review

Breast implant-associated anaplastic large cell lymphoma (BIA-ALCL) is a recently recognized non-Hodgkin lymphoma of T-cell origin. Despite the low incidence of this new disease, the increasing use of breast implants for cosmetic or post-mastectomy reconstruction purposes places BIA-ALC as an emerging and compelling medical challenge. The real BIA-ALCL pathogenesis has not been fully uncovered so far, while different putative causal factors have been proposed. Breast implants with textured surfaces seem to be associated with nearly all cases of BIA-ALCL, while the real the risk of disease development has not been well estimated so far. Late onset, persistent seroma around breast implant represents the classical clinical presentation. Most of the BIA-ALCL patients presents with localized disease, which confers an excellent prognosis. Unlike other non-Hodgkin lymphomas, surgical excision of the mass has a key role in the treatment. For patients with advanced and disseminated diseases, the treatment did not differ from other types of T-cell lymphoma. For these reasons, BIA-ALCL represents an emerging disease which requires multidisciplinary team approach to well define diagnostic workup and treatment for each patient. This review article aims to summarize available data on BIA-ALCL. First, we will outline available data on BIA-ALCL epidemiology, pathogenesis, diagnostic work-up, and treatment. Second, we will point out the potential psychological implications as well as the risk of perception distortion for women with breast implants, especially for those with previous breast cancer. Lastly, we will summarize the current national recommendations regarding textured breast implants and discuss the diagnostic-therapeutic algorithm for BIA-ALCL management.

Lymphomas arising in immune-privileged sites: insights into biology, diagnosis, and pathogenesis

Session 2 of the 2018 European Association of Hematopathology/Society for Hematopathology Workshop focused on lymphomas arising in immune-privileged sites: both lymphomas arising in the traditionally described "immune sanctuary" sites of the central nervous system (CNS) and testes, as well as those arising at sites of local immune privilege. Primary CNS large B cell lymphoma and primary testicular large B cell lymphoma were discussed, and the biology of these unique tumors was highlighted by several cases showing the classic mutation profile including MYD88 L265P and CD79B. The tendency of these tumors to involve both the CNS and testis was also reinforced by several cases. Four cases of low-grade B cell lymphomas (LGBCL) of the CNS were discussed. Two were classic Bing-Neel syndrome associated with LPL, and two were LGBCL with plasmacytic differentiation and amyloid deposition without systemic disease. Rare examples of systemic T and NK cell lymphomas involving the CNS were also discussed. Several cases of breast implant-associated anaplastic large cell lymphoma (BI-ALCL) were submitted showing the typical clinicopathologic features. These cases were discussed along with a case with analogous features arising in a patient with a gastric band implant, as well as large B cell lymphomas arising alongside foreign materials. Finally, large B cell lymphomas arising in effusions or localized sites of chronic inflammation (fibrin-associated diffuse large B cell lymphoma [DLBCL] and DLBCL associated with chronic inflammation) were described. The pathogenesis of all of these lymphomas is believed to be related to decreased immune surveillance, either innate to the physiology of the organ or acquired at a local site.

Finding Consensus After Two Decades of Breast Implant-Associated Anaplastic Large Cell Lymphoma

Breast implant-associated anaplastic large cell lymphoma (BIA-ALCL) is an emerging and indolent, but potentially fatal cancer of the immune system that can develop around textured-surface breast implants. The World Health Organization first recognized BIA-ALCL as a unique clinical entity in 2016. To date, over 600 confirmed cases have been reported worldwide. BIA-ALCL most commonly presents with disease confined to the capsule, as a seroma or a mass adjacent to the implant. While BIA-ALCL has a fairly indolent clinical course, with an excellent prognosis in early stage disease, disseminated cancer and death have also been reported. In this review, the authors focus on the early diagnosis and treatment, including reconstructing the breast following BIA-ALCL, and also discuss recently updated National Comprehensive Cancer Network guidelines. They also review the current epidemiology and risk factors associated with BIA-ALCL. Finally, they discuss important medicolegal considerations and the bioethics surrounding the continued use of textured-surface breast implants.

Cell of Origin and Immunologic Events in the Pathogenesis of Breast Implant-Associated Anaplastic Large-Cell Lymphoma

Breast implant–associated anaplastic large-cell lymphoma (BIA-ALCL) is a CD30-positive, anaplastic lymphoma kinase–negative T-cell lymphoma. Nearly all cases have been associated with textured implants. Most cases are of effusion-limited, indolent disease, with an excellent prognosis after implant and capsule removal. However, capsular invasion and tumor mass have a more aggressive course and a fatal outcome risk. This review summarizes the current knowledge on BIA-ALCL cell of origin and immunologic factors underlying its pathogenesis. Cytokine expression profiling of BIA-ALCL cell lines and clinical specimens reveals a predominantly type 17 helper T-cell (Th17)/Th1 signature, implicating this as its cell of origin. However, a Th2 allergic inflammatory response is suggested by the presence of IL-13, with infiltration of eosinophils and IgE-coated mast cells in clinical specimens of BIA-ALCL. The microenvironment-induced T-cell plasticity, a factor increasingly appreciated, may partially explain these divergent results. Mutations resulting in constitutive Janus kinase (JAK)–STAT activation have been detected and associated with BIA-ALCL pathogenesis in a small number of cases. One possible scenario is that an inflammatory microenvironment stimulates an immune response, followed by polyclonal expansion of Th17/Th1 cell subsets with release of inflammatory cytokines and chemokines and accumulation of seroma. JAK-STAT3 gain-of-function mutations within this pathway and others may subsequently lead to monoclonal T-cell proliferation and clinical BIA-ALCL. Current research suggests that therapies targeting JAK proteins warrant investigation in BIA-ALCL.

Update on the classification of T-cell lymphomas, Hodgkin lymphomas, and histiocytic/dendritic cell neoplasms

Introduction: The classification of lymphomas is based on the postulated normal counterparts of lymphoid neoplasms and currently constitutes over 100 definite or provisional entities. As this number of entities implies, lymphomas show marked pathological, genetic, and clinical heterogeneity. Recent molecular findings have significantly advanced our understanding of lymphomas. Areas covered: The World Health Organization (WHO) classification of lymphoid neoplasms was updated in 2017. The present review summarizes the new findings that have been gained in the areas of mature T-cell neoplasms, Hodgkin lymphomas, and histiocytic/dendritic cell neoplasms since the publication of the 2017 WHO classification. Expert opinion: Although formal revisions to the WHO classification are published only periodically, our understanding of the pathologic, genetic, and clinical features of lymphoid neoplasms is constantly evolving, particularly in the age of -omics technologies and targeted therapeutics. Even in the relatively short time since the publication of the 2017 WHO classification, many significant findings have been identified in the entities covered in this review.

Achieving Reliable Diagnosis in Late Breast Implant Seromas: From Reactive to Anaplastic Large Cell Lymphoma

Late onset of fluid collection surrounding breast implants may represent a serious issue when considering the possibility of breast implant-associated anaplastic large cell lymphoma, a newly recognized type of T-cell malignancy. However, many other factors, including trauma and infections, may be implicated in the formation of non-neoplastic periprosthetic delayed effusions. An appropriate management of late seromas, consisting of ultrasound-guided fluid drainage, cultures, cytology, and immunocytochemical and T-cell clonality studies, should be performed to achieve a correct and prompt diagnosis of breast implant-associated anaplastic large cell lymphoma. Criticisms in the diagnosis of late peri-implant effusions are here discussed in detail.