Primary cutaneous marginal zone B-cell lymphoma: a clinical, histopathological, immunophenotypic and molecular genetic study of 22 cases

H pylori-Negative MALT-Associated Extranodal Marginal Zone Lymphoma: A Comprehensive Case Report and Literature Review

Extranodal marginal zone B-cell lymphoma (ENMZL) of mucosa-associated lymphoid tissue (MALT), a rare subtype of B-cell lymphoma, is typically associated with Helicobacter pylori (H pylori) infection, especially in gastric cases. However, this article presents 2 unique cases of H pylori-negative colonic ENMZL, challenging the conventional understanding of the disease. The first case involves an 80-year-old male diagnosed with Stage 1E ENMZL in the descending colon, and the second describes a 74-year-old male with sigmoid colon ENMZL. Both cases lacked H pylori infection, adding complexity to their management. Accompanying these case studies is a comprehensive literature review, delving into the epidemiology, pathology, clinical features, diagnosis, and treatment of H pylori-negative ENMZL, with a focus on gastrointestinal involvement. This review highlights the importance of considering H pylori-negative cases in ENMZL diagnosis and management, illustrating the need for further research and individualized treatment approaches in this uncommon lymphoma subtype.

Annular skin tumors and lymphoproliferative diseases

Determining the shape of a skin lesion may provide a diagnostic clue in dermatology practice, more commonly for inflammatory diseases but also for skin tumors. The annular formation may develop by diverse mechanisms in skin tumors. Annular lesions may occur from the onset of the tumor as sparing the central area or depression and/or ulceration in the center of the tumor or outward expansion of the primary lesion. Clustering of multiple papulonodular lesions sparing the central area or relatively independent processes acting on the central and peripheral components of the tumor may also result in an annular appearance. We have explored a wide variety of benign and malignant skin tumors and lymphoproliferative diseases forming an annular shape.

CD30 expression in cutaneous B-cell lymphomas

INTRODUCTION

CD30 expression has been infrequently described in cutaneous B-cell lymphomas (CBCLs). We examined CD30 expression in reactive lymphoid hyperplasia (RLH) and CBCL and correlated expression with clinicopathologic features.

METHODS

CD30 was examined in 82 CBCL patients and 10 RLH patients that had been evaluated in our cutaneous lymphoma clinics. The CBCL patients included: primary cutaneous follicle center lymphoma (PCFCL), Grade 1/2 systemic/nodal follicular lymphoma (SFL); primary cutaneous marginal zone lymphoma/lymphoproliferative disorder (PCMZL/LPD); systemic marginal zone lymphoma (SMZL); primary cutaneous diffuse large B-cell lymphoma, leg type (PCDLBCL-LT); and extracutaneous/systemic diffuse large B-cell lymphoma (eDLBCL). We scored CD30 expression for intensity and extent and related CD30 expression to age at first diagnosis, sex, site of biopsy, clinical appearance, extracutaneous involvement, multiple cutaneous lesions, B-symptoms, lymphadenopathy, positive positron emission tomography/computed tomography (PET/CT), elevated lactate dehydrogenase (LDH), and positive bone marrow biopsy.

RESULTS

CD30 expression was identified in 35% of CBCL, ranging from few, weak, scattered cells to strong and diffuse expression. It was most common in PCFCL and was not expressed in PCDLBCL-LT. Rare PCFCL expressed strong, diffuse CD30. Some cases of PCMZL/LPD, SMZL, FL, and RLH showed scattered, strongly positive cells. CD30 expression in CBCL was associated with favorable clinical features: younger age, negative PET/CT, and an LDH within normal limits.

CONCLUSIONS

CD30 may be expressed in CBCL, possibly causing diagnostic confusion. CD30 expression was most commonly identified in PCFCL and is associated with favorable clinical features. In cases with strong and diffuse expression, CD30 could be a therapeutic target.

Annular skin tumors and lymphoproliferative diseases

Determining the shape of the skin lesion may provide a diagnostic clue in dermatology practice, more commonly for inflammatory diseases but also for skin tumors. The annular formation may develop by diverse mechanisms in skin tumors. Annular lesions may occur from the onset of the tumor as sparing the central area or depression and/or ulceration in the center of the tumor or outward expansion of the primary lesion. Clustering of multiple papulonodular lesions sparing the central area or relatively independent processes acting on the central and peripheral components of the tumor may also result in an annular appearance. We have explored a wide variety of benign and malignant skin tumors and lymphoproliferative diseases forming an annular shape.

Primary cutaneous blastic marginal zone lymphoma: A comprehensive clinical, light microscopic, phenotypic and cytogenetic appraisal

BACKGROUND

Primary cutaneous marginal zone lymphoma (PCMZL) is a form of indolent lymphoproliferative disease where the disease is largely a cutaneous confined process. It is typically a neoplasm composed of post germinal small B-cells and light chain restricted plasma cells in a background of reactive T-cell hyperplasia and benign germinal centers. Rarely a significant degree of large cell infiltration occurs warranting the categorization as blastic marginal zone lymphoma.

MATERIALS AND METHODS

We reviewed our data base over a time period of 2016 to 2022 for cases diagnosed as blastic MZL. Twelve cases were identified. The clinical records and pathological data were reviewed.

RESULTS

Nine of the cases represented de novo forms of blastic MZL while in three cases there was a prior history of MZL. Multifocal cutaneous disease was not uncommon and one quarter of the cases had evidence of extracutaneous dissemination. All patients except three achieved remission with varied therapeutic interventions depending on the extent of the disease ranging from conservative re-excision to chemotherapy. No patient died from lymphoma. Light microscopically, there was evidence of a background of conventional MZL in the majority of cases. The large cell component was typically characterized by multiple micronodular aggregates throughout the dermis although in three cases there was a striking diffuse large cell component as the dominant infiltrate. Phenotypically, a third of the cases showed either CD5 or CD23 positivity amidst neoplastic B cells. Significant staining for BCL-2 was noted in the majority of cases tested while extensive MUM-1 positivity was observed in half of the cases tested. Kappa or lambda light chain restriction was seen in most. The Ki67 proliferation index exceeded 30 % in all cases. There was C-MYC positivity in two cases. While most cases did not detect cytogenetic abnormalities, one case had multiple cytogenetic hits that are associated with diffuse large B cell lymphoma. Next generation sequencing showed a Ten-eleven translocation 2 mutation in the earlier biopsy prior to transformation and in the later biopsy after transformation along with an additional B2M mutation in the transformed biopsy. Both types of mutations are very uncommon but held to contribute to tumor progression in the setting of diffuse large B cell lymphoma.

CONCLUSION

Blastic MZL is associated with a more aggressive clinical course. Even when there is disseminated disease patients while not always cured did not have a fatal course in this series. The light microscopic findings are reproducible. The background of MZL, identification of larger cells in significant numbers without a follicle center phenotype, at times expressing CD5 or CD23 with variable positivity for MUM1, BCL-2 and C-MYC and a high proliferation index define the pathology in most. Certain cytogenetic abnormalities and genetic mutations implicated in large cell transformation into a diffuse large B cell lymphoma are seen in blastic MZL with earlier biopsies prior to transformation potentially harboring at risk genetic mutations.

Localized lymphomatoid papulosis: Unilesional lymphomatoid papulosis, regional lymphomatoid papulosis, and persistent agmination of lymphomatoid papulosis

Lymphomatoid papulosis (LYP), the most common primary cutaneous CD30-positive lymphoproliferative disorder, is heralded by multiple papular and nodular lesions at anatomically discontiguous cutaneous sites. The histologic patterns are protean. An uncommon form of LYP is one that is anatomically confined. Cases of unilesional LYP, regional LYP, and persistent agmination of LYP were encountered in the routine and consultative practices of Weill Cornell Medicine, Division of Dermatopathology. The clinical presentation, outcomes, light microscopic findings, and phenotypic profile are reviewed. There were 10 cases of LYP presenting as solitary plaques or nodules primarily occurring in older patients and without a relevant medical history in most. Most cases occurred at an acral site with many localized to the foot; the morphology was one of a necrotizing angiocentric type E pattern and borderline type C morphology. Two of the unilesional patients in our series went on to develop mycosis fungoides, one at the initial site of unilesional type A LYP, and the other at a discontiguous site. Excluding one case, the solitary lesions underwent complete regression; after the lesions regressed, some cases had no apparent recurrence. The second anatomically confined variant of LYP in our series was regional LYP exhibiting a type E morphology in two cases and a hybrid type A and granulomatous eccrinotropic morphology in one case. There was no subsequent development of lymphoma, nor was there any spread to additional anatomic sites. The final category was persistent agmination of LYP, whereby the agminated papules of LYP were superimposed on a plaque of cutaneous T-cell lymphoma represented by mycosis fungoides in two and follicular helper T-cell lymphoma in one. In conclusion, anatomically confined LYP defines an uncommon form of LYP, but it is an important one to recognize because the histology can be worrisome despite an indolent clinical course. The clinical presentation, the infrequent association with lymphoma/leukemia, and histology are similar to conventional LYP, although there appears to be a greater tendency for complete regression without recurrence, excluding cases of persistent agmination of LYP whereby the clinical course warrants categorization as a form of cutaneous T cell lymphoma (CTCL).

Update in Diagnosis and Management of Primary Cutaneous B-Cell Lymphomas

Primary cutaneous lymphomas are a rare group of diseases, with an estimated incidence of 0.5-1 case per 100,000 people per year. Primary cutaneous B-cell lymphomas (pCBCLs) represent 25-30% of all primary cutaneous lymphomas. There are three main subtypes of pCBCL: primary cutaneous marginal zone lymphoma, primary cutaneous follicle center lymphoma, and primary cutaneous diffuse large B-cell lymphoma, leg type. Cutaneous B-cell lymphomas have a broad spectrum of clinical presentations, which makes diagnostic and therapeutic strategies challenging. To date, treatment recommendations for cutaneous B-cell lymphomas have been largely based on small retrospective studies and institutional experience. Recently, the pharmacotherapeutic landscape has expanded to include drugs that may modify the underlying disease pathology of pCBCLs, representing new therapeutic modalities for this rare group of diseases. Novel therapies used for other systemic B-cell lymphomas show promise for the treatment of pCBCLs and are being increasingly considered. These new therapies are divided into five main groups: monoclonal antibodies, immune checkpoint inhibitors, small-molecule inhibitors, bispecific T-cell engaging, and chimeric antigen receptor T cell. In this review, we discuss the clinical, histopathological, molecular, and cytogenetic features of the most common pCBCL subtypes with a focus on current and innovative therapeutic developments in their management. These emerging treatment strategies for B-cell lymphomas and cutaneous B-cell lymphomas may represent novel first-line options for the management of these rare diseases.

Histological Transformation and Clonal Relationship of Subcutaneous Marginal Zone B-Cell Lymphoma and Diffuse Large B-Cell Lymphoma

ABSTRACT

Histological transformation (HT) is an exceptionally uncommon and poorly understood event where a low-grade or indolent B-cell lymphoma transforms into a more aggressive entity, typically diffuse large B-cell lymphoma (DLBCL). The pathogenesis is unclear; however, HT is associated with a worse prognosis. This article reports a unique case of marginal zone lymphoma (MZL) limited to skin/subcutis (confirmed with PET-CT) that subsequently developed DLBCL, followed by nodal MZL. We explored phenotypic, molecular genetic, and cytogenetic findings in subcutaneous MZL with HT to DLBCL and subsequent progression to systemic MZL. Shared clonal peaks between the tumors were demonstrated through immunoglobulin heavy chain PCR, and genomic microarray analysis revealed both unique genomic abnormalities and shared regions of copy-neutral loss of heterozygosity in all specimens. BCL-2 expression was present in the original subcutaneous MZL, lost on conversion to Primary cutaneous diffuse large B cell lymphoma (PCDLBCL)-NOS, and regained during subsequent transformation to systemic MZL. The PCDLBCL-NOS did not demonstrate FISH rearrangements for MYC, BCL2, and BCL6. Here, we describe the histologic, immunophenotypic, and cytogenetic abnormalities of the clonally related transformation of subcutaneous MZL, PCDLBCL-NOS, and eventual systemic MZL. The predominantly subcutaneous presentation of MZL may be associated with a more aggressive outcome and raises consideration for careful evaluation of patients who present with this pattern.

Pediatric Cutaneous Hematologic Disorders: Cutaneous Lymphoma and Leukemia Cutis: Experience of a Tertiary-Care Pediatric Institution and Review of the Literature

BACKGROUND

Cutaneous hematologic malignancies are rare in children, and the literature about them is still sparse.

OBJECTIVE

The purpose of our study was to report our experience with pediatric cases of cutaneous hematologic disorders and describe their clinical and histological features.

METHODS

Data were retrospectively collected from the histopathologic database of the CHU Sainte-Justine, University of Montreal, Montreal, Canada. All patients up to 18 years of age with a diagnosis of a primary cutaneous lymphoma (including lymphomatoid papulosis), secondary cutaneous lymphoma or cutaneous manifestations of leukemia, followed from 1980 to 2019 at our center were reviewed.

RESULTS

Thirty-six patients were included. Age at presentation ranged from birth to 18 years of age (mean 7.83 ± 5.16; median 7.0). Ten different hematologic disorders were identified according to the WHO-EORTC classifications: lymphomatoid papulosis (10 cases), mycosis fungoides (6 cases), anaplastic large cell lymphoma (4 cases), pre-B acute lymphoid leukemia (5 cases), primary cutaneous marginal zone B-cell lymphoma (4 cases), primary cutaneous CD4⁺medium T-cell lymphoproliferative disorder (1 case), extranodal NK/T-cell lymphoma (1 case), hydroa vacciniforme-like lymphoproliferative disorder (1 case), B-cell lymphoblastic lymphoma (1 case) and acute myeloid leukemia (3 cases).

CONCLUSION

The most common subtype of cutaneous hematologic disease in our single institution study was lymphomatoid papulosis (type A and type C), followed by mycosis fungoides. Recognition of this large clinical and histological spectrum by dermatologists is important because diagnosis is often established by biopsy of skin lesions, even in secondary cutaneous cases. Moreover, the clinicopathological correlation is of utmost importance for the final diagnosis of those pathologies.

Deep Sequencing of Immunoglobulin Genes Identifies a Very Low Percentage of Monoclonal B Cells in Primary Cutaneous Marginal Zone Lymphomas with CD30-Positive Hodgkin/Reed–Sternberg-like Cells

The spectrum of cutaneous CD30-positive lymphoproliferative disorders encompasses both inflammatory and neoplastic conditions. CD30+ Hodgkin and Reed–Sternberg-like cells have been occasionally reported in primary cutaneous marginal zone lymphoma, where they are thought to represent a side neoplastic component within a dominant background of lymphomatous small B cells. Herein, we describe the histological and molecular findings of three cases of primary cutaneous marginal zone lymphomas with CD30+ H/RS cells, in which next-generation sequencing analysis revealed the clonal population to consist in less than 5% of the cutaneous B-cell infiltrate, providing a thought-provoking focus on a possible main role for CD30+ cells in primary cutaneous marginal zone lymphoproliferations.

A review of CD30 expression in cutaneous neoplasms

BACKGROUND

The surface protein CD30 is a therapeutic target of monoclonal antibody therapy. Knowledge of the frequency of CD30 expression and its prognostic relevance is therefore interesting, not only in lymphoproliferative disorders (LPD) but also in solid tumors of the skin.

METHODS

A review was completed in PubMed for all published reports of CD30 expression in cutaneous lymphomas, mastocytosis, epithelial tumors and sarcomas from 1982 to April 2019. Only accessible articles in English and German were considered. Entities with an expected CD30 expression, such as CD30-positive LPD, were not evaluated.

RESULTS

The electronic research identified 1091 articles and a further 34 articles were obtained from manual bibliographic reference. Overall 91 articles were included that examined CD30 expression in various entities of cutaneous neoplasms and matched the inclusion criteria.

CONCLUSION

Apart from cutaneous CD30-positive LPD, the best-studied group for CD30 expression was mycosis fungoides (MF). CD30 positivity was found in 32% of classical (patch and plaque stage) and in 59.4% cases of transformed MF. CD30 was also frequently expressed in cutaneous mastocytosis (96.5%). In solid tumors, some single reports describe CD30 expression by tumor cells, but CD30-reactive lymphocytes were frequently observed in the tumor microenvironment (TME), especially in keratoacanthoma (KA).

Kappa and lambda immunohistochemistry and in situ hybridization in the evaluation of atypical cutaneous lymphoid infiltrates

BACKGROUND

Atypical cutaneous lymphoid infiltrates are challenging lesions in dermatopathology. We present a summary of the literature regarding kappa and lambda immunohistochemistry (IHC) and in situ hybridization (ISH) in the evaluation of atypical cutaneous or mucosal lymphoid infiltrates.

METHODS

Relevant articles from 1967 to 2018 in the English language were identified and summarized. In the absence of larger studies, case series of n ≥ 3 were included.

RESULTS

Sixty-three articles assessing kappa and lambda IHC and/or ISH were identified. Most focused on marginal zone lymphomas. Other lymphomas included follicle center lymphoma, diffuse large B-cell lymphoma, chronic lymphocytic leukemia/small lymphocytic lymphoma, mantle cell lymphoma, lymphoplasmacytic lymphoma, plasmablastic lymphoma, multiple myeloma, monoclonal gammopathy of undetermined significance, and polyneuropathy, organomegaly, endocrinopathy, monoclonal protein, skin changes (POEMS). Non-neoplastic lesions included reactive lymphoid hyperplasia, cutaneous plasmacytosis, connective tissue disease, IgG4-related disease, acrodermatitis chronic atrophicans, Zoon balanitis, dermatitides, and infiltrates around epithelial dysplasias/neoplasias.

CONCLUSION

Kappa and lambda IHC and ISH are useful tools in the evaluation of cutaneous B-cell lymphomas and plasma cell neoplasms. The literature supports that the detection of light-chain restriction by IHC and ISH is one of the most useful findings in the differential diagnosis of reactive lymphoid hyperplasia vs B-cell lymphoma with plasmacytic differentiation.

How I Diagnose Primary Cutaneous Marginal Zone Lymphoma

OBJECTIVES

Primary cutaneous marginal zone lymphoma (PCMZL) is 1 of the 3 major subtypes of primary cutaneous B-cell lymphoma. The diagnosis of PCMZL may be challenging, as the differential diagnosis includes benign cutaneous lymphoproliferations as well as other primary or secondary cutaneous B-cell or T-cell lymphomas. This review describes our approach to the diagnosis of PCMZL.

METHODS

Two cases are presented that illustrate how we diagnose each of the 2 subtypes of PCMZL. The clinicopathologic features of PCMZL and the ways in which these cases can be distinguished from both benign and other neoplastic entities are emphasized.

RESULTS

A definitive diagnosis of PCMZL requires the incorporation of histologic and immunophenotypic features, molecular genetic studies in some cases, and just as importantly, clinical findings. Emerging data suggest that the heavy chain class-switched cases may be more like a clonal chronic lymphoproliferative disorder.

CONCLUSIONS

The 2 subtypes of PCMZL create different diagnostic challenges and require the use of a multiparameter approach. Although very indolent, it is important to distinguish PCMZLs from reactive proliferations, because they frequently recur and may require antineoplastic therapies. It is also critical to distinguish PCMZLs from other B- or T-cell lymphomas so that patients are properly evaluated and not overtreated.

Diagnosis and Treatment of Primary Cutaneous B-Cell Lymphomas: State of the Art and Perspectives

Primary cutaneous B-cell lymphomas are rare entities that develop primarily in the skin. They constitute a heterogeneous group that represents around a quarter of primary cutaneous lymphomas. The 2018 update of the World Health Organization-European Organization for Research and Treatment of Cancer (WHO-EORTC) classification differentiates primary cutaneous marginal zone lymphoma and primary cutaneous follicle center lymphoma with an indolent course from primary cutaneous diffuse large B-cell lymphoma, leg type with an aggressive behavior. The broad spectrum of clinical presentations and the disease course marked by frequent relapses are diagnostic and therapeutic challenges. The classification of these diseases has been refined in recent years, which allows to better define their immunopathogenesis and specific management. In the present article, we review the main clinico-biological characteristics and the current therapeutic options of these three main subsets. Based on the recent therapeutic advances in nodal B-cell lymphomas, we focus on the development of novel treatment options applicable to primary cutaneous B-cell lymphomas, including targeted therapies, combination treatments and immunotherapeutic approaches, and cover basic, translational and clinical aspects aiming to improve the treatment of cutaneous B-cell lymphomas.

Primary thymic MALT lymphoma in a patient with Sjögren's syndrome and multiple lung cysts: a case report

Background

Thymic mucosa-associated lymphoid tissue (MALT) lymphoma is rare and also known for its association with autoimmune diseases, especially Sjögren’s syndrome (SjS), which could affect the systemic organs, and pulmonary involvement often reveals multiple lung cysts.

Case presentation

A 40-year-old woman presented with an anterior mediastinal mass and multiple lung cysts on computed tomography. We suspected thymoma concomitant with lymphangioleiomyomatosis and performed a total thymectomy and wedge resection of the lung as a surgical biopsy. The histopathological diagnosis of the mediastinal mass was a MALT lymphoma, and there were no specific findings in the lung specimen. She had a history of SjS, which had been overlooked during the initial work-up.

Conclusions

A history of SjS should raise suspicion of a MALT lymphoma for the differential diagnosis of an anterior mediastinal mass. A precise history taking is crucial for the correct diagnosis, and we could have avoided a lung resection in our case.

Cutaneous lymphomas-An update 2019

Primary cutaneous lymphomas (CL) are the second most common form of extranodal lymphomas. Cutaneous T-cell lymphomas represent the majority. They are classified according to the WHO classification 2017 and the updated WHO-EORTC 2018 published in the fourth edition of the WHO classification for Skin Tumors monograph. Primary cutaneous acral CD8+ T-cell lymphoma and EBV-positive mucocutaneous ulcer have been listed as new provisional entities. Moreover, the histological and genetic spectrum of lymphomatoid papulosis has been expanded. Recently, prognostic subtypes were delineated for some entities and subtypes of CL such as folliculotropic mycosis fungoides and marginal zone lymphoma. Since CL show overlapping histological features, clinico-pathological correlation is of outmost importance for the diagnosis. Recent studies revealed new biomarkers and genetic alterations underlying the pathogenesis of CL. Moreover, targeted therapies have widened the treatment options particularly for aggressive lymphomas.

Immunohistochemistry in Dermatopathology and its Relevance in Clinical Practice

Immunohistochemistry (IHC) is an important diagnostic tool in histopathology. Dermatopathology is a rapidly developing subspecialty of histopathology. Although IHC is not widely used in routine dermatopathology practice, its application is gradually increasing. IHC is used to differentiate two conditions with similar morphology, to confirm a diagnosis as well as to assess prognosis. It is more commonly used for neoplastic conditions like melanocytic, hematolymphoid, and spindle cell tumors, although uses can be very wide. Although IHC can aid in diagnosis, sometimes interpretation can be difficult as there may be overlapping findings. Thus, IHC should not be interpreted in isolation and should be done in the context of clinical and histological findings. In this review, we have discussed the uses of various immunohistochemical markers in dermatopathology in the light of current literature and their clinical relevance.

Primary Cutaneous B-cell Lymphomas

B-cell lymphomas represent approximately 20% to 25% of primary cutaneous lymphomas. Within this group, most cases (>99%) are encompassed by 3 diagnostic entities: primary cutaneous marginal zone lymphoma, primary cutaneous follicle center lymphoma, and primary cutaneous diffuse large B-cell lymphoma, leg type. In this article, the authors present clinical, histopathologic, immunophenotypic, and molecular features of each of these entities and briefly discuss the rarer intravascular large B-cell lymphoma.

Primary cutaneous B-cell lymphoma: narrative review of the literature

Primary cutaneous B-cell lymphomas comprehend a group of lymphoproliferative disorders characterized by being monoclonal proliferations of B-cell primarily involving the skin. Despite being recognized as autonomous and distinct clinico-pathologic entities since the late 80s, their classification is still an ongoing matter of debate. At the moment, WHO classification recognizes three disorders: primary cutaneous marginal zone lymphoma, primary cutaneous follicle center lymphoma and primary cutaneous diffuse large b-cell lymphoma (leg type). Primary cutaneous diffuse large b-cell lymphoma (other) has been used to define rare cases which show histologically an infiltrate with diffuse pattern composed by large b-cell, but not fitting with criteria for follicle center lymphoma nor for primary cutaneous diffuse large b-cell lymphoma (leg type). Aim of this review was to briefly describe all recognized and provisional entities included in the primary cutaneous b-cell lymphomas and to discuss recent acquisitions that may influence their future classifications.

Managing Patients with Cutaneous B-Cell and T-Cell Lymphomas Other Than Mycosis Fungoides

Cutaneous lymphomas (CL) are a heterogeneous group of neoplasms characterized with clinical and histopathological variation, as well as overlap with benign dermatoses. Diagnosis and treatment of CLs is challenging and often requires a multidisciplinary approach. However, prognostic knowledge of these conditions and awareness of treatment options can help optimize appropriate use of available regimens, thereby improving care for patients. Here, we review the most recent literature and outline treatment themes for managing patients with cutaneous B-cell and T-cell lymphomas other than mycosis fungoides.

[Treatment of indolent cutaneous B‑cell lymphoma]

Primary cutaneous B‑cell lymphomas are rarely encountered and represent 25% of all cutaneous lymphomas. Follicular B‑cell lymphoma and marginal zone lymphoma belong to indolent subtypes which as a rule have no systemic dissemination and, thus, a mostly unchanged life expectancy. Therefore, skin-directed treatment options such as excision or radiotherapy are usually sufficient to control the disease. In contrast, cutaneous diffuse large B‑cell lymphoma and EBV-associated B‑cell lymphomas of the skin belong to more aggressive entities which demand a systemic first-line upfront therapy with R‑CHOP. Nevertheless, mortality is still high and comparable to that of systemic/nodal large B‑cell lymphomas so that the identification of pathogenetic driver mutations or novel therapeutic targets may pave the way to better target-oriented therapies.

A Literature Revision in Primary Cutaneous B-cell Lymphoma

The term “Primary Cutaneous B-Cell Lymphoma” (PCBCL) comprehends a variety of lymphoproliferative disorders characterized by a clonal proliferation of B-cells primarily involving the skin. The absence of evident extra-cutaneous disease must be confirmed after six-month follow-up in order to exclude a nodal non-Hodgkin's lymphoma (NHL) with secondary cutaneous involvement, which may have a completely different clinical behavior and prognosis. In this article, we have summarized the clinico-pathological features of main types of PCBCL and we outline the guidelines for management based on a review of the available literature.

A new era for cutaneous CD30-positive T-cell lymphoproliferative disorders

Cutaneous CD30+ T-cell lymphoproliferative disorders (CD30+ T-LPD) represent a spectrum encompassing lymphomatoid papulosis (LyP), primary cutaneous anaplastic large-cell lymphoma (pcALCL) and borderline lesions. They share the expression of CD30 as a common phenotypic marker. They differ however in their clinical presentation, the histological features and clinical course. Moreover, LyP and PcALCL show numerous clinical, histological and phenotypic variants. Overlapping features of LyP and pcALCL with themselves and with other cutaneous and systemic lymphomas emphasize the importance of careful clinicopathologic correlation and staging in the diagnosis of CD30+ T-LPD. Furthermore, an increasing number of inflammatory and infectious skin disorders harboring medium-sized to large CD30+ cells have to be considered in the differential diagnosis. Whereas the expression of CD30 in cutaneous CD30+ T-LPD stands for a favourable prognosis, its expression in other cutaneous and systemic lymphomas has a divergent impact. The assessment of CD30 expression does not only provide prognostic information, but is of potential therapeutic relevance as CD30 can serve as a therapeutic target. This review focuses on the clinicopathological and phenotypic spectrum of CD30+ T-LPD, its differential diagnoses and the role of CD30 as a diagnostic, prognostic and therapeutic marker.

Primary Cutaneous Lymphomas in Children and Adolescents

Primary cutaneous lymphomas are rare in children and mostly represented by mycosis fungoides and CD30(+) lymphoproliferative disorders. Most pediatric cutaneous lymphomas have similar clinical/pathological features as their adult counterparts, particularly the T-cell subtypes. With regard to outcome, adult cutaneous mature T-cell lymphomas have a tendency to progression, while this appears to be relatively infrequent in children. The outcome of cutaneous B-cell lymphomas depends on subtype, with the B-lymphoblastic entity being associated with similar outcomes to precursor B acute lymphoblastic leukemia, while there are insufficient data on other entities. The diagnosis and treatment of these patients require a close collaboration between experienced pediatric pathologists, dermatologists, and oncologists. Prospective collection of longitudinal clinical and biological data from children with these rare lymphomas is needed to better understand their biological and clinical behavior and to ultimately discover the best therapeutic strategies.

[Primary cutaneous B-cell lymphomas: study of 22 cases]

INTRODUCTION AND OBJECTIVES

Primary cutaneous B-cell lymphoma (CBCL) is a very low prevalence neoplasm and constitutes 25% of all primary cutaneous lymphomas. Our objective was to discover the epidemiological, clinic and histologic characteristics of CBCL in our area.

METHODS

Retrospective descriptive study with patients with histologic diagnosis of CBCL followed up in our department between 2004 and 2015.

RESULTS

Twenty-two patients with CBCL were included; 65% were men and 35% were women. Follicle centre lymphoma was the most common subtype (41%). Only 3 cases presented with node involvement and one with bone marrow invasion. Five recurrences were detected and one patient died because of the CBCL.

DISCUSSION AND CONCLUSIONS

This is one of the first CBCL series in theSpanish population. The incidence, sex, age, subtype distribution, clinical features and immunohistochemical patterns are very similar to those of the other series.

Approach to Cutaneous Lymphoid Infiltrates: When to Consider Lymphoma?

Cutaneous lymphoid infiltrates (CLIs) are common in routine dermatopathology. However, differentiating a reactive CLI from a malignant lymphocytic infiltrate is often a significant challenge since many inflammatory dermatoses can clinically and/or histopathologically mimic cutaneous lymphomas, coined pseudolymphomas. We conducted a literature review from 1966 to July 1, 2015, at PubMed.gov using the search terms: Cutaneous lymphoma, cutaneous pseudolymphoma, cutaneous lymphoid hyperplasia, simulants/mimics/imitators of cutaneous lymphomas, and cutaneous lymphoid infiltrates. The diagnostic approach to CLIs and the most common differential imitators of lymphoma is discussed herein based on six predominant morphologic and immunophenotypic, histopathologic patterns: (1) Superficial dermal T-cell infiltrates (2) superficial and deep dermal perivascular and/or nodular natural killer/T-cell infiltrates (3) pan-dermal diffuse T-cell infiltrates (4) panniculitic T-cell infiltrates (5) small cell predominant B-cell infiltrates, and (6) large-cell predominant B-cell infiltrates. Since no single histopathological feature is sufficient to discern between a benign and a malignant CLI, the overall balance of clinical, histopathological, immunophenotypic, and molecular features should be considered carefully to establish a diagnosis. Despite advances in ancillary studies such as immunohistochemistry and molecular clonality, these studies often display specificity and sensitivity limitations. Therefore, proper clinicopathological correlation still remains the gold standard for the precise diagnosis of CLIs.

Extranodal Marginal Zone B-Cell Lymphoma/Maltoma of the Lip in a Child

All forms of cutaneous lymphomas are rare in children. Extranodal marginal zone B-cell lymphomas (EMZBL)/mucosa-associated lymphoid tissue (MALT) lymphomas are unusual neoplasms in children and young adults. We report a case of an EMZBL/MALT lymphoma of the lip in a previously healthy 14-year-old boy without immunodeficiency, confirmed by immunohistochemistry and documentation of clonal rearrangement of the immunoglobulin heavy-chain gene. Additionally, we present a review of the differential diagnosis of skin and mucosal lymphoid proliferations in childhood.

Primary cutaneous marginal zone lymphoma in children: a report of 3 cases and review of the literature

: Primary cutaneous marginal zone lymphoma (PCMZL) is one of the most common cutaneous B-cell lymphomas. It affects mostly patients in their fourth decade and manifests with multifocal nodules mostly on the arms and upper trunk in more than half of the patients. PCMZL is, however, rare in children and adolescents, with only 20 cases reported in patients aged 20 and younger. The authors present 3 cases of PCMZL in teenagers. The patients were 2 girls aged 18 and 13 and a 17-year-old boy. Two patients presented with multiple lesions involving various anatomic sites, whereas in 1 patient, 2 small closely opposed papules on the abdomen were seen. Histopathologically, the characteristic appearance of PCMZL was found in 3 of 4 specimens, with nodular infiltrates composed of small lymphocytes in the interfollicular compartment, reactive germinal centers, and plasma cells in small clusters mainly at the periphery of the infiltrates, whereas 1 specimen showed a dense lymphocytic infiltrate with small granulomas. Clonality was demonstrated by monotypic immunoglobulin light chain expression and/or monoclonal rearrangement of the immunoglobulin heavy chain genes. No Borrelia burgdorferi was identified on serology or by polymerase chain reaction in any of the cases. Treatment included excision or administration of antibiotics with complete remission in all the 3 patients indicating that PCMZL in children and young adolescents follows the same indolent course with a tendency for recurrences, but excellent prognosis as in adults. The pertinent literature on PCZL in childhood and adolescence is reviewed.

Paediatric cutaneous lymphomas: a review and comparison with adult counterparts

Primary cutaneous lymphomas (CL) in children is rare. Only a few studies focused specifically on paediatric CL and therefore little is known whether primary CL in children are similar to or different from their adult counterparts with respect to the clinicopathological presentation, behaviour and prognosis. An extensive literature search using PubMed/MEDLINE from January 1995 through July 2014 was undertaken for articles reporting cases of paediatric CL. In addition, we identified 31 children with CL in our institutions. Mycosis fungoides and lymphomatoid papulosis are the two most prevalent lymphoma forms in children. A few entities of cutaneous lymphomas such as cutaneous diffuse large B-cell lymphoma leg type, and Sézary syndrome have not been reported so far in children. Other lymphoma entities such as hydroa vacciniforme-like lymphoma are mostly seen in certain geographic areas (Asia, Central and South America). In the paediatric population, low-malignant indolent forms such as primary cutaneous marginal zone lymphoma and primary cutaneous follicle centre lymphoma are very rare, whereas the more aggressive forms of B-cell lymphomas, precursor lymphoblastic lymphomas, and blastic plasmacytoid dendritic cell neoplasm are the most common forms in children, mostly involving the skin secondarily. Most paediatric lymphomas have similar clinicopathological features and course as their adults counterparts, particularly in the group of cutaneous T-cell lymphomas. The spectrum of cutaneous B-cell lymphomas in children significantly differs from the one in adults. Diagnostic work-up and treatment of paediatric patients with lymphomas are best achieved in close collaboration with paediatric haematopathologists and oncologists.

A Case of a Laryngeal MALT Lymphoma in a Patient with a History of Gastric MALT

We are reporting a case of a 62-year-old African American woman with a history of gastric MALT lymphoma successfully treated with radiation who presented with a laryngeal MALT lymphoma 4 years after her original diagnosis. She received definitive radiation with a complete response. The case presented is unique for the rare presentation of a MALT lymphoma in the larynx, especially in light of the patient's previously treated gastric MALT lymphoma years ago.

PD-1, S-100 and CD1a expression in pseudolymphomatous folliculitis, primary cutaneous marginal zone B-cell lymphoma (MALT lymphoma) and cutaneous lymphoid hyperplasia

BACKGROUND

Pseudolymphomatous folliculitis is a lymphoid proliferation that clinically and histopathologically mimics primary cutaneous extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma). In this study, we assessed the diagnostic value of three immunohistochemical markers, programmed death-1 (PD-1), CD1a and S100.

METHODS

We evaluated 25 cases of cutaneous lymphoid proliferations with established diagnoses, including 9 patients with pseudolymphomatous folliculitis, 11 with MALT lymphoma, and 5 with cutaneous lymphoid hyperplasia (CLH). The clinical, histopathologic and immunohistochemical characteristics were reviewed and three major characteristics assessed: (a) proportion of T cells expressing PD-1, (b) pattern of expression of CD1a by dendritic cells and (c) pattern of expression of S100 by dendritic cells.

RESULTS

We found pseudolymphomatous folliculitis to have a significant increase in PD-1+ T cells compared with MALT lymphoma (p < 0.0001). The pattern of CD1a staining is also informative: MALT lymphoma is significantly more likely to demonstrate a peripheral concentration of CD1a+ dendritic cells around lymphoid nodules than pseudolymphomatous folliculitis (p < 0.0003) or CLH (p < 0.05). Pseudolymphomatous folliculitis demonstrates an interstitial distribution of CD1a+ cells more often than MALT lymphoma (p < 0.04). S100 staining was not a helpful discriminator.

CONCLUSIONS

Histopathologic factors including PD-1 and CD1a staining patterns may allow for more certainty in distinguishing lymphoid hyperplasia, including pseudolymphomatous folliculitis, from MALT lymphoma.

Cutaneous lymphomas: an update. Part 2: B-cell lymphomas and related conditions

: Primary cutaneous B-cell lymphomas (PCBCL) are the second most common form of primary cutaneous lymphomas and account for approximately 25%-30% of all primary cutaneous lymphomas. Both forms of low-grade malignant PCBCL, primary cutaneous follicle center lymphoma (PCFCL) and primary cutaneous marginal zone lymphoma of mucosa-associated lymphoid tissue-type (MALT lymphoma) (PCMZL) represent the vast majority of PCBCL and show an indolent slowly progressive course and an excellent prognosis despite a high recurrence rate. Genetic analysis indicates that PCMZL differ from other forms of extranodal MALT lymphomas. The more common class-switched and the non-class-switched form of PCMZL can be distinguished as two distinctive subsets that differ in the cellular composition, IgM expression, and biological behavior with extracutaneous involvement found in the non-class-switched form. Recently, unusual clinical and histological forms of PCMZL and PCFCL manifesting with miliary or agminated lesions have been described that are diagnostically challenging. In contrast to PCMZL and PCFCL, primary cutaneous diffuse large B-cell lymphoma, leg type, and other rare forms of large B-cell lymphomas such as intravascular large B-cell lymphoma have an unfavorable prognosis. There is an emerging group of Epstein-Barr virus (EBV)-driven B-cell lymphoproliferations including posttransplant lymphoproliferative disorders and mucocutaneous ulcer occurring in immunocompromised patients and EBV-associated diffuse large B-cell lymphoma of the elderly arising in the setting of senescence-linked immunodeficiency. This review reports on recent findings expanding the spectrum of clinicopathological features, differential diagnostic aspects, and the pathogenesis of PCBCL and discusses the group of EBV-associated B-cell lymphoproliferations involving the skin.

Biopsies of facial dermatoses made simple

CONTEXT

Biopsy of the face is rarely done for inflammatory skin diseases, unless the entire process is confined to the face.

OBJECTIVE

We hypothesized that facial dermatitis has a differential diagnosis that is more limited than the differential diagnosis of inflammatory skin diseases that affect other parts of the body. To our knowledge, the classification of inflammatory skin diseases occurring on the face has never been conducted before in the English literature.

DESIGN

The most-recent 100 facial biopsies of inflammatory skin conditions were retrieved from our files, and the cases were categorized into the main inflammatory skin patterns.

RESULTS

Forty-seven cases (47%) were categorized as interface dermatitis, 2 cases (2%) as psoriasiform dermatitis, 11 cases (11%) as spongiotic dermatitis, 16 cases (16%) as diffuse and nodular dermatitis, 8 cases (8%) as perivascular dermatitis, 14 cases (14%) as folliculitis and perifolliculitis, 1 case (1%) as panniculitis, and 1 case (1%) as fibrosing dermatitis. The number of diagnostic entities represented within each of these patterns was small.

CONCLUSIONS

We believe that facial dermatitis should have its own more-circumscribed differential diagnosis. From a practical viewpoint, many of the inflammatory skin diseases that affect other parts of the body should be excluded from the differential diagnosis after the tissue is determined to be from a facial skin biopsy, and others should not be considered unless the biopsy is from the face.

Cutaneous CD30-Positive Lymphoproliferative Disorders

Cutaneous CD30+ lymphoproliferative disorders are the second most common types of cutaneous T-cell lymphomas. They represent a well-defined spectrum encompassing lymphomatoid papulosis (LyP), primary cutaneous anaplastic large-cell lymphoma (pcALCL), and borderline lesions. They share the expression of CD30 as a common phenotypic hallmark, but they differ in their clinical presentation, course, and histologic features. New variants have been recently identified, including CD8+ epidermotropic LyP type D, angioinvasive LyP type E, and ALK-positive pcALCL. This review describes clinical, histopathologic, and phenotypic variants; their differential diagnoses (benign and malignant); and the role of CD30 as a diagnostic, prognostic, and therapeutic marker.

Primary cutaneous B-cell lymphomas: part I. Clinical features, diagnosis, and classification

Primary cutaneous B-cell lymphomas (PCBCLs) are defined as lymphomas with a B-cell phenotype that present in the skin without evidence of systemic or extracutaneous disease at initial presentation, after adequate staging. In non-Hodgkin lymphomas, the skin is the second most common site of extranodal involvement after the gastrointestinal tract. PCBCLs are histologically very similar to their nodal counterparts, and these histologic similarities can lead to confusion about both therapy and prognosis. This article will summarize the clinical, pathologic, and diagnostic features of the 3 main types of PCBCL: primary cutaneous follicle center lymphoma, primary cutaneous marginal zone lymphoma, and primary cutaneous diffuse large B-cell lymphoma, leg-type, and the appropriate evaluation and staging procedures for each of these entities.

Blastic marginal zone lymphoma: a clinical and pathological study of 8 cases and review of the literature

INTRODUCTION

Blastic transformation (BT) of marginal zone lymphoma or mucosa-associated lymphoid tissue lymphoma has been mainly reported in the spleen and stomach. Primary cutaneous marginal zone lymphoma that undergoes BT is rare and not well documented. We describe 8 patients with blastic primary cutaneous marginal zone lymphoma and compare the clinical, pathologic, and molecular findings of these patients with 10 cases previously reported in the literature.

RESULTS

The cases of blastic marginal zone lymphoma could be categorized into cases of de novo blastic marginal zone lymphoma and large-cell transformation arising in a background of a history of biopsy proven marginal zone lymphoma. The cases of de novo blastic marginal zone lymphoma occurred in elderly patients without any medical history. In each of the cases, the lesions were radiated, not treated, or treated with complete excision without any death due to lymphoma nor was there any evidence of extracutaneous dissemination. Large-cell transformation arising in background of marginal zone lymphoma typically occurred in patients who were younger; 2 of the 4 cases were immunocompromised. The clinical course in each of the cases was aggressive with 3 of the 4 patients succumbing to disseminated disease while 1 patient developed extracutaneous nodal disease. Phenotypically, there was an expression of CD5 in a total of 3 of the 8 cases and CD23 in 3 of the 8 cases. Commonality of B-cell clones was demonstrated in 2 cases where biopsies were available of both the less aggressive appearing marginal zone lymphoma and the transformed biopsies. Cytogenetic abnormalities associated with BT included a deletion of chromosome 7q in all cases tested.

CONCLUSION

Large-cell transformation arising in a patient with a history of marginal zone lymphoma portends a worse prognosis, including death from disseminated disease, whereas a de novo presentation of blastic marginal zone lymphoma may define a clinical course similar to other forms of low-grade cutaneous B-cell lymphoma. The expression of CD5 and CD23 may define a phenotypic profile associated with BT. It is possible that marginal zone lymphomas associated with CD5 and CD23 positivity should be followed more closely and/or treated with radiation and/or complete excision.

Marginal zone lymphomas and infectious agents

A link with infectious agents, bacteria and viruses in particular, has been reported for many lymphoma entities. Marginal zone lymphomas (extranodal, nodal and splenic forms) are frequently associated with chronic infections, with important clinical, molecular, biological, and therapeutic implications. The well-known correlation between Helicobacter pylori and gastric MALT-lymphoma, the recently reported links between Chlamydophila psittaci and ocular adnexal MALT-lymphoma and Borrelia burgdorferi and cutaneous MALT lymphoma constitute the best studied examples of lymphomagenic activity of bacteria, while the hepatitis C virus represents the most extensively investigated virus associated with marginal zone lymphomas. Biological and clinical features, therapeutic implications and future perspectives of these lymphoma-microbial associations are discussed in this review.

Primary cutaneous marginal zone B-cell lymphoma: response to treatment and disease-free survival in a series of 137 patients

BACKGROUND

Primary cutaneous marginal zone B-cell lymphomas are low-grade lymphomas running an indolent course. Skin relapses have been frequently reported but little information about disease-free survival (DFS) is available.

OBJECTIVE

We sought to evaluate relapse rate and DFS in patients with primary cutaneous marginal zone B-cell lymphomas.

METHODS

Clinical features, European Organization for Research and Treatment of Cancer/International Society for Cutaneous Lymphomas stage, light chain restriction, clonality, treatments, skin relapses, DFS, stage progression, extracutaneous disease, and outcome are analyzed in a series of 137 patients.

RESULTS

Patients were classified as solitary lesion (T1) (n = 70; 51%), regional skin involvement (T2) (n = 40; 29%), and generalized skin lesions (T3) (n = 27; 20%). Surgical excision, local radiotherapy, or a combination were the initial treatment in 118 patients (86%). In 121 of 137 patients (88%) a complete remission was observed after initial treatment, including 99 of 106 patients (93%) with solitary or localized disease and 22 of 31 patients (71%) with multifocal lesions. Cutaneous relapses were observed in 53 patients (44%). Median DFS was 47 months. Patients with multifocal lesions or T3 disease showed higher relapse rate and shorter DFS. No significant differences were observed between surgery and radiotherapy, but surgery alone was associated with more recurrences at initial site. Overall survival at 5 and 10 years was 93%. Six patients (4%) developed extracutaneous disease during follow-up.

LIMITATIONS

This was a case series retrospective study.

CONCLUSION

Our results support long-term follow-up in patients with primary cutaneous marginal zone B-cell lymphomas. Disseminated skin lesions have higher relapse rate and shorter DFS suggesting further investigation on systemic therapies in such a group of patients.

[Splenic marginal zone B-cell lymphoma with epidermotropic skin involvement]

Marginal zone B-cell lymphoma (MZL) is subclassified into extranodal MZL of mucosa-associated lymphoid tissue (including cutaneous lymphomas), splenic MZL, and nodal MZL. We report the case of a 68-year-old man with erythematous-violaceous plaques and nodules. Skin biopsy showed an epidermotropic lymphocytic infiltration and cytology and immunohistochemistry were consistent with MZL. The workup revealed disease in the peripheral blood and bone marrow and massive splenomegaly. Splenectomy confirmed the diagnosis of splenic MZL and led to resolution of the skin lesions. Cutaneous recurrence was treated successfully with chemotherapy and rituximab but caused fatal hepatitis due to hepatitis B virus reactivation. Skin involvement by splenic MZL is uncommon; this form of the disease can present epidermotropism, a very rare finding in primary cutaneous MZL. Treatment consists of splenectomy, which may be associated with chemotherapy and/or rituximab; this treatment may lead to reactivation of latent hepatitis B infection and screening for hepatitis should therefore be performed prior to starting therapy.