ALK-Negative Anaplastic Large Cell Lymphoma: Current Concepts and Molecular Pathogenesis of a Heterogeneous Group of Large T-Cell Lymphomas

EBV-Positive Nodal T- and NK-Cell Lymphoma Mimicking Anaplastic Large Cell Lymphoma: A Case Report

EBV-positive nodal T- and NK-cell lymphoma (EBV+ NT/NKCL) is a recently recognized entity in the 5th edition of the WHO Classification of Tumors of Hematopoietic and Lymphoid Tissues. Notably, CD30 positivity is frequently observed in (EBV+ NT/NKCL), creating diagnostic challenges to distinguish it from ALK-negative anaplastic large cell lymphoma (ALCL). Furthermore, cases of EBV+ ALCL have been documented in the literature, predating the inclusion of EBV+ nodal cytotoxic T-cell lymphoma as a variant of peripheral T-cell lymphoma. We present a case of a 47-year-old male presenting with multiple lymphadenopathies. The histomorphologic and immunophenotypic features of the lymph node closely resemble ALK-negative ALCL, characterized by uniform CD30 expression and a subcapsular distribution of lymphoma cells. However, the lymphoma cells exhibit diffuse positivity for EBV, consistent with EBV+ NT/NKCL. A case of ALK-negative ALCL with an immunophenotype identical to the EBV-positive case is included for comparison. Given that EBV+ NT/NKCL represents an aggressive neoplasm requiring unique clinical management compared to ALK-negative ALCL, it is critical to accurately differentiate EBV+ NT/NKCL from ALK-negative ALCL with a cytotoxic T-cell immunophenotype.

Anaplastic Large Cell Lymphoma With Intraocular or Ocular Adnexal Involvement: A Case Report and Systematic Review

PURPOSE

To review the existing literature on patients with anaplastic large cell lymphoma (ALCL) affecting the globe and/or ocular adnexa, and to present a report documenting the clinical course of a patient with ALCL that involved their globe and ocular adnexa.

METHODS

PubMed, Scopus, and Google scholar were systematically searched for all cases of ALCL involving intraocular or adnexal ocular structures from inception to May 2023. Moreover, a new reported case added to the cases found in searches.

RESULTS

The review identified 1680 studies, with 8 meeting inclusion criteria. A total of 9 patients were included with a mean age of 29.7 years (median: 30.0, range: 1.3-48). Primary ALCL was present in 5/9 (55.6%) patients. The most common ophthalmic manifestations included periorbital swelling (5/8), chemosis (5.8), and decreased vision (5/7). Misdiagnoses were initially made in 3 patients, and the lag time to correct diagnosis from 3 weeks to 3 months. CD30 expression was positive in all cases, and 6/9 patients were positive for anaplastic lymphoma kinase, resulting in 6/9 patients being diagnosed with anaplastic lymphoma kinase-positive ALCL. In terms of management modalities, chemotherapy was administered in 8/9 patients, while radiation therapy was utilized in 4/9 patients, and 2 underwent autologous stem cell transplantation. Five (55.6%) patients succumbed to ALCL while 4 (44.4%) were alive and disease-free at the last follow-up. The median times from the initial presentation of ALCL to death, ophthalmic presentation to death, and diagnosis to death were 4.12 months (range: 1.1-168.0), 2.62 months (range: 1.1-144), and 4.00 months (range: 0.10-168), respectively. The median follow-up duration was 21.0 months (range: 1.1-168.0).

CONCLUSIONS

ALCL involving the globe and ocular adnexa is a rare and highly malignant tumor that can mimic benign clinical conditions. Early biopsy and aggressive treatment with chemotherapy regimens such as CHOP and radiation therapy may be useful.

Primary cutaneous anaplastic large-cell lymphoma resembling infratemporal space infection: a case report

BACKGROUND

Primary cutaneous anaplastic large-cell lymphoma (PC-ALCL) is a rare T-cell lymphoma belonging to the CD30 + T-cell lymphoproliferative disorders. The case of PC-ALCL in the temporal region is exceedingly rare. Herein, we report a case of PC-ALCL involving the temporal region mimicking infratemporal space infection.

CASE PRESENTATION

A 78-year-old woman presented to maxillofacial surgery service with a 6-month history of swelling and pain in the left side of her face. Laboratory investigations found an elevated C-reactive protein (CRP). Imaging findings showed enlarged lymph nodes and extensive thickening of subcutaneous tissue of the left temples. Based on these findings, the infratemporal space infection was suspected initially. The patient underwent incision and drainage, and we unexpectedly found no pus in the lesion area. Incisional biopsy showed necrosis and extensive involvement of the left temples by a diffuse infiltrate containing large, atypical cells. The tumor cells were positive for CD30, CD3, Ki67. They were negative for ALK (SP8), CD5, CD8, CD20 and PAX5. After considering these findings, a diagnosis of PC-ALCL was rendered. The patient was admitted to the lymphoma department for systemic chemotherapy and no relapse occurred during a follow-up period of six months.

CONCLUSIONS

This report suggests that if there are suspicious intraoperative manifestations, carrying out a biopsy simultaneously, using Hematoxylin and eosin (HE) staining, and a comprehensive Immunohistochemistry (IHC) panel are essential to diagnosing PC-ALCL to prevent misdiagnosis.

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.

Case Report: A recurrent case of ALK-ALCL after autologous transplantation was successfully treated with BV + a modified CHEP chemotherapy containing mitoxantrone hydrochloride liposome with the addition of chidamide maintenance therapy

Background

ALK-negative anaplastic large cell lymphoma (ALK-ALCL) is a rare heterogeneous malignancy of T-cell origin.ALK- ALCL has a poor prognosis, with more patients experiencing relapses and refractory to treatment, and its treatment remains challenging. We report a case with bone involvement as the main clinical manifestation of recurrent, and the patient achieved significant partial remission after brentuximab vedotin(BV) combined with a modified CHEP chemotherapy containing mitoxantrone hydrochloride liposome (PLM60) with the addition of chidamide maintenance therapy and received regular follow-up, with a disease-free survival of 16 months to date. A literature review of the clinical presentation and treatment of ALCL was also conducted to identify strategies for its diagnosis and management.

Conclusions

ALK-ALCL with bone involvement as the main manifestation of recurrent is relatively rare. Here, BV combined a modified CHEP chemotherapy containing mitoxantrone hydrochloride liposome was applied for the first time in a patient with relapsed ALK-ALCL, inducing remission and extending survival. However, further prospective studies with many patients are needed to determine the biological characteristics of this rare type of ALK-ALCL and relevant treatment strategies.

When Lymphoma Strikes the Pancreas: A Rare Presentation of Systemic Anaplastic Lymphoma Kinase-Negative Anaplastic Large Cell Lymphoma in a Human Immunodeficiency Virus-Positive Patient

Anaplastic lymphoma kinase (ALK)-negative anaplastic large cell lymphoma (ALCL) is an uncommon subtype of non-Hodgkin lymphoma, with pancreatic involvement being exceedingly rare and documented in only a handful of case reports. We present a unique case of a 31-year-old human immunodeficiency virus (HIV)-positive male with multisite ALK-negative ALCL, who initially presented with a buttock ulcer, leading to a suspicion of primary cutaneous ALCL or lymphomatoid papulosis. However, the discovery of multiple extracutaneous sites, including an atypical pancreatic head involvement, confirmed the diagnosis of systemic ALK-negative ALCL with cutaneous manifestation. The patient received six cycles of brentuximab vedotin + cyclophosphamide-doxorubicin-prednisone (BV + CHP) treatment, achieving a substantial reduction in the size of the pancreatic head mass and no detectable fluorodeoxyglucose (FDG) uptake on positron emission tomography (PET) scan. This case underscores the diagnostic challenges of ALK-negative ALCL in HIV-positive patients with extranodal presentations and demonstrates the potential effectiveness of targeted therapeutic strategies for such cases.

Anaplastic Large-cell Lymphoma Involving Gastrointestinal Tract: A Clinicopathologic Study of 25 Cases of a Rare Tumor at a Rare Site

Background. Anaplastic large-cell lymphoma (ALCL) is an uncommon lymphoma divided into anaplastic lymphoma kinase (ALK) positive, ALK negative, and breast implant-associated (BIA) ALCL. Gastrointestinal tract involvement is very rare and may be difficult to diagnose. Its recognition is crucial as prognostic ramifications are different. Objectives. To describe clinicopathological features of ALCL involving the gastrointestinal tract. Materials and Methods. Slides were reviewed. Diagnosis was confirmed. Histological and immunohistochemical features were described. Results.Twenty-five tumors were diagnosed during the study period. Ages ranged from 14 to 65 years (mean 41 years). Mean age for ALK-negative and ALK-positive patients were 49 and 17 years, respectively. Twenty-one were males and 4 were females. Eighteen involved small intestine. Mean tumor size was 4.2 cm. All showed diffuse sheets of large anaplastic cells with pleomorphic nuclei, abundant pink cytoplasm, and strong positivity for CD30. Epithelial membrane antigen was positive in 17 tumors and keratin was negative in all. Eighteen tumors were ALK negative. Out of 14 patients with follow-up, 12 died within a few months of diagnosis. Seven had stage IE, 5 had stage IIE, and 2 had stage IV disease. Two patients were alive at 35 and 60 months. Twelve received chemotherapy. Conclusion. A marked male predominance was noted. Small intestine was the commonest site of involvement. Majority were ALK negative. ALK-negative tumors occurred in older patients and ALK positive in younger patients. Prognosis was poor. ALCL should be included in the differential diagnosis of anaplastic epithelioid cell neoplasms in the gastrointestinal tract.

Constant small-cell changes and variable LEF1 expression in DUSP22-rearranged primary cutaneous anaplastic large-cell lymphoma: Analysis of the repeated biopsies of three patients

DUSP22-rearranged primary cutaneous anaplastic large-cell lymphoma (pcALCL) has a biphasic histological pattern defined by large dermal atypical lymphocytes and epidermotropic small lymphocytes resembling pagetoid reticulosis, but the positivity rate of the biphasic pattern in DUSP22-rearranged pcALCL is unknown. Immunohistochemically, LEF1 expression in >75% of tumor cells is associated with DUSP22-rearrangement (DUSP22-R) in systemic ALCL. However, whether this association applies to pcALCL remains unclear. To analyze these pathological clues for screening DUSP22-R, we reviewed 11 skin biopsies from three patients with DUSP22-rearranged pcALCL. All specimens showed a biphasic pattern, of which three showed nonpagetoid infiltration of the epidermis. In all lesions, small-cell changes of tumor cells were observed not only within the epidermis but also under the epidermis. LEF1 positivity rates varied by lesion (range: 30%-90%, mean: 59.6%) with only three patients expressing LEF1 in more than 75% of tumor cells. In conclusion, the biphasic pattern was a constant finding in DUSP22-rearranged pcALCL, but it was not always pagetoid reticulosis-like. The recognition of small-cell change outside the epidermis may be helpful in diagnosing DUSP22-rearranged pcALCL. However, LEF1 expression was variable and its diagnostic usefulness may be limited.

Primary Cutaneous Anaplastic Large Cell Lymphoma-A Review of Clinical, Morphological, Immunohistochemical, and Molecular Features

Primary cutaneous anaplastic large cell lymphoma (ALCL) is the second most common cutaneous T-cell lymphoma after mycosis fungoides and belongs to the spectrum of cutaneous CD30+ T-cell lymphoproliferative disorders. Although primary cutaneous ALCL usually presents as a localized nodule or papule with or without ulceration, multifocal lesions may occur in up to 20% of cases. Histologically, primary cutaneous ALCL consists of a diffuse dermal infiltrate of medium to large anaplastic/pleomorphic cells with abundant amphophilic-to-eosinophilic cytoplasm, horseshoe-shaped nuclei, strong and diffuse expression of CD30, and with focal or no epidermotropism. The neoplastic infiltrate may show angiocentric distribution and may extend to the subcutis. Patients with localized or multifocal disease have a similar prognosis with a 10-year overall survival rate of 90%. Approximately 30% of primary cutaneous ALCLs harbor a DUSP22 (6p25.3) gene rearrangement that results in decreased expression of this dual-specific phosphatase, decreased STAT3 activation, and decreased activity of immune and autoimmune-mediated mechanisms regulated by T-cells.

Nodal peripheral T-cell lymphoma: Chemotherapy-free management, are we there yet?

Peripheral T-cell lymphomas (PTCLs) are a diverse and uncommon type of lymphoid malignancies with a dismal prognosis. Recent advances in genomic studies have shown recurring mutations that are changing our knowledge of the disease's molecular genetics and pathogenesis. As such, new targeted therapies and treatments to improve disease outcomes are currently being explored. In this review, we discussed the current understanding of the nodal PTCL biology with potential therapeutic implications and gave our insights on the promising novel therapies that are currently under study such as immunotherapy, chimeric antigen receptor T-cell therapy, and oncolytic virotherapy.

ALK-positive Large B-Cell Lymphoma With Multiple Epithelial Antigen Expression and PABPC1::ALK Fusion: A Novel Molecular Alteration

Anaplastic lymphoma kinase (ALK)-positive large B-cell lymphoma (LBCL) is a very rare type of LBCL with an aggressive clinical course and poor prognosis. This diagnosis can be challenging given the varied morphology (immunoblastic, plasmablastic, or anaplastic), frequent lack of B-cell antigens, and especially in cases with expression of epithelial antigens. Here, we report a case of ALK-positive LBCL with unusual expression of 4 epithelial-associated markers (AE1/AE3, CK8/18, EMA, and GATA3) and novel poly(A) binding protein cytoplasmic 1 (PABPC1)::ALK fusion which has not been previously reported in this entity. This case also emphasizes the use of comprehensive immunophenotyping that includes multiple lineage-specific antibodies when faced with a malignancy without a clear differentiation to avoid misdiagnosis. This case only achieved partial response to combination chemotherapy, radiation, and ALK inhibitor regimens, and furthers our understanding of this uncommon lymphoma.

Soft-Tissue Anaplastic Lymphoma Kinase-Positive Anaplastic Large Cell Lymphoma in a Child Unmasked by COVID-19

Anaplastic large cell lymphoma (ALCL) is children's most common mature T-cell neoplasm. The majority is positive for anaplastic lymphoma kinase (ALK). Initial presentation as a soft-tissue pelvic mass without nodal involvement is rare and can be easily misdiagnosed. We report a case of a 12-year-old male presenting with pain and movement restriction in the right extremity. Computed tomography (CT) scan revealed a solitary pelvic mass. Initial biopsy examination concluded rhabdomyosarcoma. After developing pediatric multisystemic inflammatory syndrome due to coronavirus disease 2019 (COVID-19), central and peripheral lymph node enlargement appeared. New cervical adenopathy and pelvic mass biopsies were performed. Immunohistochemistry concluded an ALK-positive ALCL with a small-cell pattern. The patient was treated with brentuximab-based chemotherapy and eventually improved. Differential diagnosis of pelvic masses in children and adolescents must include ALCL. An inflammatory trigger may promote the appearance of a typical nodal disease, previously absent. Attention is warranted during histopathological examination to avoid diagnostic errors.

Systemic ALK-negative anaplastic large cell lymphoma with distinctive myxoid change and DUSP22 rearrangement

Systemic anaplastic lymphoma kinase-negative (ALK-) anaplastic large cell lymphoma (ALCL) comprises a genomically heterogeneous disease that is considered a distinct entity by the 2016 World Health Organization Classification of Tumours of Haematopoietic and Lymphoid Tissues. Other than lymph nodes, systemic ALK- ALCL may affect extranodal tissues, sites where the inflammatory background may be especially prominent. In this scenario, myxoid change is exceptional in systemic ALK- ALCL. We describe a rare case of systemic ALK- ALCL with distinctive myxoid changes, carrying specific chromosomal aberrations that affect the clinical outcome. Careful morphological, immunohistochemical, and molecular workup is mandatory because a myxoid background should not be a reason to ignore the possibility of a lymphoma. Finally, extensive correlation with staging and the detection of prognostic biomarkers such as DUSP22 and TP63 rearrangements are essential for the diagnosis and prediction of clinical outcome in ALK- ALCL.

Genetics Abnormalities with Clinical Impact in Primary Cutaneous Lymphomas

Simple Summary

The genetic landscape of cutaneous T-cell lymphomas analyzed by sequencing high throughput techniques shows a heterogeneous somatic mutational profile and genomic copy number variations in the TCR signaling effectors, the NF-κB elements, DNA damage/repair elements, JAK/STAT pathway elements and epigenetic modifiers. A mutational and genomic stratification of these patients provides new opportunities for the development or repurposing of (personalized) therapeutic strategies. The genetic heterogeneity in cutaneous B-cell lymphoma parallels with the specific subtype. Damaging mutations in primary cutaneous diffuse large B-cell lymphoma of the leg type, involving MYD88 gene, or BCL6 and MYC translocations or CDKN2A deletions are useful for diagnostic purposes. The more indolent forms, as the primary cutaneous lymphoma of follicle center cell (somatic mutations in TNFRSF14 and 1p36 deletions) and the cutaneous lymphoproliferative disorder of the marginal zone cells (FAS gene), present with a more restricted pattern of genetic alterations.

Abstract

Primary cutaneous lymphomas comprise a heterogeneous group of extranodal non-Hodgkin lymphomas (NHL) that arise from skin resident lymphoid cells and are manifested by specific lymphomatous cutaneous lesions with no evidence of extracutaneous disease at the time of diagnosis. They may originate from mature T-lymphocytes (70% of all cases), mature B-lymphocytes (25–30%) or, rarely, NK cells. Cutaneous T-cell lymphomas (CTCL) comprise a heterogeneous group of T-cell malignancies including Mycosis Fungoides (MF) the most frequent subtype, accounting for approximately half of CTCL, and Sézary syndrome (SS), which is an erythrodermic and leukemic subtype characterized by significant blood involvement. The mutational landscape of MF and SS by NGS include recurrent genomic alterations in the TCR signaling effectors (i.e., PLCG1), the NF-κB elements (i.e., CARD11), DNA damage/repair elements (TP53 or ATM), JAK/STAT pathway elements or epigenetic modifiers (DNMT3). Genomic copy number variations appeared to be more prevalent than somatic mutations. Other CTCL subtypes such as primary cutaneous anaplastic large cell lymphoma also harbor genetic alterations of the JAK/STAT pathway in up to 50% of cases. Recently, primary cutaneous aggressive epidermotropic T-cell lymphoma, a rare fatal subtype, was found to contain a specific profile of JAK2 rearrangements. Other aggressive cytotoxic CTCL (primary cutaneous γδ T-cell lymphomas) also show genetic alterations in the JAK/STAT pathway in a large proportion of patients. Thus, CTCL patients have a heterogeneous genetic/transcriptional and epigenetic background, and there is no uniform treatment for these patients. In this scenario, a pathway-based personalized management is required. Cutaneous B-cell lymphoma (CBCL) subtypes present a variable genetic profile. The genetic heterogeneity parallels the multiple types of specialized B-cells and their specific tissue distribution. Particularly, many recurrent hotspot and damaging mutations in primary cutaneous diffuse large B-cell lymphoma of the leg type, involving MYD88 gene, or BCL6 and MYC translocations and BLIMP1 or CDKN2A deletions are useful for diagnostic and prognostic purposes for this aggressive subtype from other indolent CBCL forms.

Primary Anaplastic Lymphoma Kinase (ALK)-Negative Anaplastic Large Cell Lymphoma (ALCL) Presenting as Perforation Peritonitis: A Case Report and Management Principles

Anaplastic large cell lymphoma (ALCL) has a characteristic feature that distinguishes it from the other types of non-Hodgkin lymphomas (NHLs) - the presence of a marker on its surface called CD30. It can be either cutaneous, systemic, or around breast implants. The systemic type of ALCL can be further classified based on the presence or absence of an abnormal protein, anaplastic lymphoma kinase (ALK), as ALK-positive or ALK-negative ALCL, respectively. We are presenting a case of a 35-year-old male who presented to the emergency department with an acute episode of abdominal pain. He underwent emergency laparotomy with ileal resection and anastomosis, as he was diagnosed with perforation peritonitis. Histological and immuno-histochemical reports of the specimen showed a lymphoproliferative lesion, and it helped reach the diagnosis of ALK-negative ALCL. ALK-negative ALCL can be diagnosed by using multidisciplinary investigation techniques, including radiological imaging, histopathological examination along with immunohistochemical staining. Prompt diagnosis helps in distinguishing ALK-negative ALCL from other lymphomas as well as solids tumors of the small bowel.

The 5th edition of the World Health Organization Classification of Haematolymphoid Tumours: Lymphoid Neoplasms

We herein present an overview of the upcoming 5^th edition of the World Health Organization Classification of Haematolymphoid Tumours focussing on lymphoid neoplasms. Myeloid and histiocytic neoplasms will be presented in a separate accompanying article. Besides listing the entities of the classification, we highlight and explain changes from the revised 4^th edition. These include reorganization of entities by a hierarchical system as is adopted throughout the 5^th edition of the WHO classification of tumours of all organ systems, modification of nomenclature for some entities, revision of diagnostic criteria or subtypes, deletion of certain entities, and introduction of new entities, as well as inclusion of tumour-like lesions, mesenchymal lesions specific to lymph node and spleen, and germline predisposition syndromes associated with the lymphoid neoplasms.

Anaplastic Large Cell Lymphoma: Molecular Pathogenesis and Treatment

Simple Summary

Anaplastic large cell lymphoma is a rare type of disease that occurs throughout the world and has four subtypes. A summary and comparison of these subtypes can assist with advancing our knowledge of the mechanism and treatment of ALCL, which is helpful in making progress in this field.

Abstract

Anaplastic large cell lymphoma (ALCL) is an uncommon type of non-Hodgkin’s lymphoma (NHL), as well as one of the subtypes of T cell lymphoma, accounting for 1 to 3% of non-Hodgkin’s lymphomas and around 15% of T cell lymphomas. In 2016, the World Health Organization (WHO) classified anaplastic large cell lymphoma into four categories: ALK-positive ALCL (ALK+ALCL), ALK-negative ALCL (ALK−ALCL), primary cutaneous ALCL (pcALCL), and breast-implant-associated ALCL (BIA-ALCL), respectively. Clinical symptoms, gene changes, prognoses, and therapy differ among the four types. Large lymphoid cells with copious cytoplasm and pleomorphic characteristics with horseshoe-shaped or reniform nuclei, for example, are found in both ALK+ and ALK−ALCL. However, their epidemiology and pathogenetic origins are distinct. BIA-ALCL is currently recognized as a new provisional entity, which is a noninvasive disease with favorable results. In this review, we focus on molecular pathogenesis and management of anaplastic large cell lymphoma.

Genetic Landscape of Peripheral T-Cell Lymphoma

Peripheral T-Cell lymphoma (PTCL) comprises a heterogenous group of uncommon lymphomas derived from mature, post-thymic or “peripheral” T- and natural killer cells. The World Health Organization (WHO) emphasizes a multiparameter approach in the diagnosis and subclassification of these neoplasms, integrating clinical, morphologic, immunophenotypic, and genetic features into the final diagnosis. Clinical presentation is particularly important due to histologic, immunophenotypic and genetic variations within established subtypes, and no convenient immunophenotypic marker of monoclonality exists. In recent years, widespread use of gene expression profiling and next-generation sequencing (NGS) techniques have contributed to an improved understanding of the pathobiology in PTCLs, and these have been incorporated into the 2016 revised WHO classification of mature T- and NK-cell neoplasms which now encompasses nearly 30 distinct entities. This review discusses the genetic landscape of PTCL and its role in subclassification, prognosis, and potential targeted therapy. In addition to discussing T-Cell lymphoma subtypes with relatively well-defined or relevant genetic aberrancies, special attention is given to genetic advances in T-Cell lymphomas of T follicular helper cell (TFH) origin, highlighting genetic overlaps between angioimmunoblastic T-Cell lymphoma (AITL), follicular T-Cell lymphoma, and nodal peripheral T-Cell lymphoma with a TFH phenotype. Furthermore, genetic drivers will be discussed for ALK-negative anaplastic large cell lymphomas and their role in differentiating these from CD30+ peripheral T-Cell lymphoma, not otherwise specified (NOS) and primary cutaneous anaplastic large cell lymphoma. Lastly, a closer look is given to genetic pathways in peripheral T-Cell lymphoma, NOS, which may guide in teasing out more specific entities in a group of T-Cell lymphomas that represents the most common subcategory and is sometimes referred to as a “wastebasket” category.

Primary Lymphomas of the Breast: A Review

Lymphomas of the breast are rare neoplasms that arise from breast lymphoid tissue and are characterised by neoplastic B or T cells. Breast lymphomas arising from B cells include, but are not limited to, diffuse large B cell lymphoma, follicular lymphoma, extra-nodal marginal zone lymphoma and Burkitt lymphoma. Anaplastic large cell lymphoma (ALCL) is of a T cell origin and both anaplastic lymphoma kinase (ALK)-positive and ALK-negative presentations have been noted in the breast. In addition, there is a more recently identified presentation of ALK-negative ALCL that arises around textured breast implants and is usually confined to a periprosthetic fibrous capsule. Here, we discuss the clinical presentations, histological and immunohistochemical features and treatment options for each type of primary breast lymphoma. We hope that this review will highlight the importance of the timely and accurate diagnosis of breast lymphoma in order to tailor the most appropriate treatment. We also wish to raise awareness of the breast implant-associated lymphomas, with the goal of stimulating work that will aid our understanding of their epidemiology and pathogenesis.