Primary cutaneous aggressive epidermotropic cytotoxic T-cell lymphomas: reappraisal of a provisional entity in the 2016 WHO classification of cutaneous lymphomas

Advances in classification and treatment of primary cutaneous lymphomas

Primary cutaneous lymphomas (PCLs) are a heterogeneous group of extranodal non-Hodgkin lymphomas, characterized with skin involvement as the primary or predominant manifestation. While early-stage PCLs typically have a favorable prognosis, managing patients with aggressive progression or advaced stages remains a challenge. Recent advancements in molecular biology and sophisticated clinical laboratory tests have significantly improved the classification and management of PCLs, which provide more targeted and effective treatment strategies for patients. This review summarizes the latest classification schemes and therapeutic options for PCLs, with a focus on the latest developments and future directions in the field.

Primary Cutaneous CD8-positive Aggressive Epidermotropic Cytotoxic T-cell Lymphoma Complicated by Paraneoplastic Encephalitis

Primary cutaneous CD8-positive aggressive epidermotropic cytotoxic T-cell lymphoma (PCAE-CTL) is a rare subtype of cutaneous T-cell lymphoma with a poor prognosis. We herein report a case of PCAE-CTL accompanied by anti-Ma2 antibody-positive paraneoplastic encephalitis. A 33-year-old woman with erythema and disturbance of consciousness was diagnosed with PCAE-CTL by a skin biopsy. Head magnetic resonance imaging revealed bilateral medial temporal lobe hyperintensity, and anti-Ma2 antibody in the cerebrospinal fluid was positive. She was diagnosed with concurrent anti-Ma2 antibody-positive paraneoplastic encephalitis. In cases of lymphoma with brain lesions, invasion of the central nervous system by lymphoma and paraneoplastic encephalitis should be considered.

Breaking Down the Barriers for Patients With Cutaneous T-Cell Lymphoma: Current Controversies and Challenges for Radiation Oncologists in 2024

Cutaneous T-cell lymphomas (CTCL) are a rare collection of diseases, frequently associated with diagnostic challenges and complex management dilemmas. The multidisciplinary team is vital for accurate clinico-pathological diagnoses and for collaborative therapeutic decisions throughout the management journey, which frequently involves multiple lines of therapy. Radiotherapy (RT) is a highly effective skin-directed therapy for CTCL, commonly delivered as localised fields or as total skin electron beam therapy (TSEBT). Mycosis fungoides (MF) is the most common of the CTCL, and patients typically experience high rates of morbidity and long natural histories of relapse and progression. Patients with MF typically present with incurable disease; in these patients, RT has an established role in symptom- and disease-control, achieving excellent response rates and proven therapeutic benefits. The role of RT continues to evolve, with modern practices favouring lower doses to reduce toxicity risks and allow for re-irradiation. Less commonly, there are situations where RT has an integral role in the potential cure of patients with MF: firstly, in the setting of unilesional MF where localised RT alone may be curative, and secondly, in the setting of preconditioning prior to curative-intent allogeneic hematopoietic stem cell transplant for patients with advanced MF/Sezary syndrome, where conventional-dose TSEBT is indicated as the most effective single agent for maximal debulking of skin disease. Radiotherapy also has an important role in the management of the less common CTCL, including the curative treatment of localised primary cutaneous anaplastic large cell lymphoma. Despite proven efficacy and quality of life benefits, disparity exists in access to RT and TSEBT. World-wide, stronger multidisciplinary collaborations and greater patient advocacy are required to increase access to RT and improve equity of care for our patients with CTCL.

Through thick and thin: confronting the aggressive cutaneous T-cell lymphomas

The cutaneous T-cell lymphomas (CTCLs) comprise a diverse set of diseases with equally diverse presentations ranging from asymptomatic solitary lesions to highly aggressive diseases with propensity for visceral spread. The more aggressive CTCLs, which herein we consider as certain cases of advanced-stage mycosis fungoides/Sézary syndrome (MF/SS), primary cutaneous CD8+ aggressive epidermotropic cytotoxic T-cell lymphoma (PCAETCL), and primary cutaneous gamma delta T-cell lymphoma (PCGDTCL), require systemic therapy. Over the last 5 years, treatment options for MF/SS have expanded with biological insights leading to new therapeutic options and increasingly unique management strategies. An enhanced appreciation of the compartmental efficacy of these agents (skin, blood, lymph nodes, visceral organs) is incorporated in current management strategies in MF/SS. In addition, approaches that combine modalities in attempts to increase depth and durability of responses across multiple compartments are being trialed. In contrast to MF/SS, PCAETCL and PCGDTCL remain diseases with few prospective studies to guide treatment. However, recent genomic insights on these diseases, such as the presence of JAK2 fusions in PCAETCL and cell of origin findings in PCGDTCL, have created options for new biomarker-driven strategies.

Efficacy of verdinexor for the treatment of naïve canine epitheliotropic cutaneous T-cell lymphoma: An open-label pilot study

BACKGROUND

Verdinexor (Laverdia-CA1; Dechra Veterinary Products), a selective inhibitor of nuclear export, has been utilised for treatment of non-Hodgkin T-cell lymphoma in dogs. However, the efficacy of verdinexor has not been evaluated for cutaneous epitheliotropic T-cell lymphoma (CETL).

HYPOTHESIS/OBJECTIVES

To evaluate the efficacy of verdinexor for the treatment of CETL.

ANIMALS

Eight client-owned animals with CETL.

MATERIALS AND METHODS

Patients received between 1.28 and 1.45 mg/kg verdinexor per os twice weekly with a minimum of 72 h between doses until disease progression or voluntary withdrawal. Adjunctive therapy with lokivetmab or prednisone was permitted after Day (D)14. Assessment of clinical lesions (canine Response Evaluation Criteria in Solid Tumors [cRECIST v1.0] and novel Canine Epitheliotropic Lymphoma Extent and Severity Index [CELESI]), pruritus (Visual Analog Scale) and treatment efficacy (owner global assessment of treatment efficacy [OGATE]) were evaluated every 14 days for 3 months, then monthly thereafter (mean 70 ± 43.4 days).

RESULTS

Seventy-five percent of patients achieved complete response, partial response or stable disease. The mean time to disease progression was 56 ± 41 days. There was a significant reduction (p = 0.026) in total CELESI score when the lowest score for each dog was compared to their score at D0. Verdinexor did not significantly reduce pruritus at any time point (p = 0.45), including when given as a monotherapy or concurrently with lokivetmab ± glucocorticoids. On D28, 75% of owners rated response to treatment as 'fair' to 'excellent'. The most common adverse effects included weight loss, inappetence, vomiting and lethargy.

CONCLUSIONS AND CLINICAL RELEVANCE

Verdinexor could be considered a safe, palliative treatment for canine CETL.

A Gastrointestinal Manifestation of Primary Cutaneous Aggressive Epidermotropic Cytotoxic T-Cell Lymphoma: A Case Report

Cutaneous T-cell lymphomas (CTCL) are the most frequently encountered form of primary cutaneous lymphoma (PCL). Although this group of diseases primarily affects the skin, extracutaneous manifestations are reported. Primary cutaneous aggressive epidermotropic cytotoxic T-cell lymphoma (pcAECTCL) is a rare form of CTCL that usually presents with an aggressive course and poor prognosis. Given the scarcity of cases, the disease is poorly understood. There have been reports of cases of extracutaneous manifestations of the disease, with more aggressive courses associated with an increased propensity for systemic spread. The most common extracutaneous manifestations of pcAECTCL include those affecting the lungs, central nervous system, testis, and oral mucosa, which can cause progressive dysphagia. We describe a patient with a chronic relapsing/remitting rash diagnosed as pcAECTCL. A positron emission tomography (PET) scan revealed diffuse uptake within the gastric region. Initial esophagogastroduodenoscopy (EGD) showed multiple ulcerations and erosions in the stomach with concern for extracutaneous spread of the patient's pcAECTCL. However, no definitive histopathological or flow immunophenotypic evidence of metastasis was found on the initial or subsequent repeat EGD.

Clinical and Histologic Variants of CD8+ Cutaneous T-Cell Lymphomas

Although the vast majority of CTCL subtypes are of the CD4+ T-helper cell differentiation phenotype, there is a spectrum of CD8+ variants that manifest wide-ranging clinical, histologic, and phenotypic features that inform the classification of the disease. CD8, like CD4, and cytotoxic molecules (including TIA and granzyme) are readily detectable via IHC staining of tissue and, when expressed on the phenotypically abnormal T-cell population, can help distinguish specific CTCL subtypes. Nonetheless, given that the histopathologic differential for CD8+ lymphoproliferative disorders and lymphomas may range from very indolent lymphomatoid papulosis (LyP) to aggressive entities like CD8+ aggressive epidermotropic cytotoxic T-cell lymphoma (AECTCL), CD8 and/or cytotoxic molecule expression alone is insufficient for diagnosis and is not in itself an indicator of prognosis. We present a review of CTCL subtypes that can demonstrate CD8 positivity: CD8+ mycosis fungoides (MF), LyP type D, subcutaneous panniculitis-like T-cell lymphoma (SPTCL), primary cutaneous gamma/delta T-cell lymphoma (PCGDTL), CD8+ AECTCL, and acral CD8+ T-cell lymphoproliferative disorder (acral CD8+ TCLPD). These diseases may have different clinical manifestations and distinctive treatment algorithms. Due to the rare nature of these diseases, it is imperative to integrate clinical, histologic, and immunohistochemical findings to determine an accurate diagnosis and an appropriate treatment plan.

Fifth Edition of the World Health Organization Classification of Tumors of the Hematopoietic and Lymphoid Tissues: Mature T-Cell, NK-Cell, and Stroma-Derived Neoplasms of Lymphoid Tissues

This review focuses on mature T cells, natural killer (NK) cells, and stroma-derived neoplasms in the fifth edition of the World Health Organization classification of hematolymphoid tumors, including changes from the revised fourth edition. Overall, information has expanded, primarily due to advancements in genomic understanding. The updated classification adopts a hierarchical format. The updated classification relies on a multidisciplinary approach, incorporating insights from a diverse group of pathologists, clinicians, and geneticists. Indolent NK-cell lymphoproliferative disorder of the gastrointestinal tract, Epstein-Barr virus-positive nodal T- and NK-cell lymphoma, and several stroma-derived neoplasms of lymphoid tissues have been newly introduced or included. The review also provides guidance on how the fifth edition of the World Health Organization classification of hematolymphoid tumors can be applied in routine clinical practice.

Primary Cutaneous Peripheral T-Cell Lymphoma NOS: Diagnostic Criteria and Challenges

ABSTRACT

Primary cutaneous peripheral T-cell lymphoma not otherwise specified (PTCL NOS) denotes lymphomas that do not conform to a recognized entity. Within this category, 3 specific lymphoproliferative diseases had been granted provisional status pending further confirmation of their validity as distinct entities; acral CD8+ lymphoma-recently accepted as acral CD8+ lymphoproliferative disorder-aggressive epidermotropic CD8+ cytotoxic T-cell lymphoma, and CD4+ small-medium T-cell lymphoproliferative disorder. The adoption of stringent diagnostic criteria, which include clinical, morphological, and immunohistochemical data, and some inherent variations of these within individual cases, raises problems as to the boundaries between these tumors and a diagnosis of PTCL NOS. This review discusses the evolution of our knowledge of these tumors and their diagnostic criteria with respect to the wider PTCL NOS category.

Update on primary cutaneous T-cell lymphomas rare subtypes

Rare subtypes of cutaneous T-cell lymphomas (CTCL) include four entities, primary cutaneous γδ T-cell lymphoma, primary cutaneous CD8+ aggressive epidermotropic cytotoxic T-cell lymphoma, and primary cutaneous CD4+ small/medium T-cell lymphoproliferative disorders, primary cutaneous acral CD8+ T-cell lymphoma, which were previously considered provisional and are now included in the new 5th World Health Organization classification of hematolymphoid tumors as distinct entities. An updated summary of the clinical, histological, and genomic characteristics of these uncommon CTCL subtypes is given in this review, with a focus on the growing body of knowledge regarding their classification and possible treatment strategies.

Chronic Radiation Dermatitis Secondary to Narrow-Band Ultraviolet B Therapy in a Patient With Primary Cutaneous CD8 + T-Cell Lymphoma With Cytotoxic Granules

ABSTRACT

Conventional therapies for CD8 + cutaneous T-cell lymphoma include topical steroids, topical nitrogen mustard, topical bexarotene, ultraviolet B therapy, psoralen and ultraviolet A therapy, local radiotherapy, and interferon alfa; however, these treatments are often found to be ineffective. Presented is a case of CD8 + cutaneous T-cell lymphoma with near-complete response to narrow-band ultraviolet therapy because of chronic radiation dermatitis initially believed to be possible progression of a CD8 + cutaneous epidermotropic cytotoxic T-cell lymphoma.

Clinical efficacy of recombinant canine interferon-gamma therapy in dogs with cutaneous epitheliotropic T-cell lymphoma

BACKGROUND

The antitumour effects of interferon-gamma (IFN-γ) in humans with cutaneous epitheliotropic T-cell lymphoma (CETCL) have been described; however, the efficacy of IFN-γ in dogs has not been investigated.

HYPOTHESIS/OBJECTIVES

The aim of this study was to evaluate the efficacy of recombinant canine IFN-γ (rCaIFN-γ) therapy in dogs with CETCL.

ANIMALS

Twenty dogs with CETCL recruited from seven veterinary clinics were enrolled in the study.

MATERIALS AND METHODS

Fifteen dogs were treated with rCaIFN-γ, and five control dogs were treated with prednisolone. We evaluated survival time, skin lesions (erythema, nodules, ulcers and bleeding), pruritus and general condition (sleep, appetite and body weight). In the rCaIFN-γ group, a questionnaire regarding the therapy was administered to owners after the dogs died.

RESULTS

No significant differences existed in the median survival time between the rCaIFN-γ and control groups (log-rank test: p = 0.2761, Wilcoxon's rank sum test: p = 0.4444). However, there were significant differences in ulcer, bleeding, pruritus, sleep, appetite and body weight between the groups (Wilcoxon-Mann-Whitney U-test: p = 0.0023, p = 0.0058, p = 0.0005, p = 0.0191, p = 0.0306 and p = 0.0306, respectively). Two (40%) of five dogs were euthanised in the control group, compared with none in the rCaIFN-γ group. Fourteen questionnaires were collected, and owners reported that they were satisfied with the rCaIFN-γ treatment.

CONCLUSIONS AND CLINICAL RELEVANCE

Although the median survival time was not prolonged, rCaIFN-γ could be helpful in maintaining good quality of life for dogs with CETCL.

Probable Primary Cutaneous CD8+ Aggressive Epidermotropic Cytotoxic T-cell Lymphoma: A Case Report of a Diagnostic Challenge

Primary cutaneous CD8+ aggressive epidermotropic cytotoxic T-cell lymphoma is a rare variety of cutaneous lymphoma. This subtype has an aggressive and quickly progressive clinical course with a survival time of 32 months from the commencement of skin lesions. This article describes a probable case of primary cutaneous CD8+ aggressive epidermotropic cytotoxic T-cell lymphoma in a 63-year-old female, which manifested as diffuse non-pruritic erythematous plaques and nodules. The diagnosis of this possible entity was aided by the histopathological and immunohistochemical findings, while immunohistochemistry for T-cell receptor (TCR) gamma/delta could not be done.

Rapidly Progressive Multiple Skin Plaques and Nodules: A Quiz

Abstract is missing (Quiz)

Aggressive Cutaneous Lymphomas and Their Mimics

Cutaneous lymphomas encompass a heterogeneous group of neoplasms with a wide spectrum of clinical presentations, histopathologic features, and prognosis. Because there are overlapping pathologic features among indolent and aggressive forms and with systemic lymphomas that involve the skin, clinicopathologic correlation is essential. Herein, the clinical and histopathologic features of aggressive cutaneous B- and T-cell lymphomas are reviewed. Indolent cutaneous lymphomas/lymphoproliferative disorders, systemic lymphomas, and reactive processes that may mimic these entities are also discussed. This article highlights distinctive clinical and histopathologic features, increases awareness of rare entities, and presents new and evolving developments in the field.

Nasolabial Ulcerated Placard Revealing a Primary Cutaneous Aggressive Epidermotropic CD8+ T-cell Lymphoma

Primary cutaneous aggressive epidermotropic CD8+ T-cell lymphoma is a rare entity representing less than 1% of cutaneous lymphomas. It has an aggressive clinical manifestation with a poor prognosis. It is characterized by cytotoxic and epidermotropic CD8+ proliferation. It also expresses the TIA-1 marker. We report a new case for its display and aggressive character, diagnostic difficulty, and good therapeutic response to chemotherapy. This is a 62-year-old female patient admitted to the hospital for a nasolabial ulcerated placard evolving for two years. Clinical examination revealed submandibular lymph nodes. The specimen analysis associated with anatomoclinical manifestation was concluded for a primary cutaneous aggressive epidermotropic CD8+ T-cell lymphoma. Tumor extent assessment did not show any secondary localization. The blood tests and serology were unremarkable. The patient had benefited from a CHOEP-type multidrug therapy protocol with complete healing of the lesion after three courses of chemotherapy.

Chimeric Antigen Receptor Based Cellular Therapy for Treatment Of T-Cell Malignancies

T-cell malignancies can be divided into precursor (T-acute lymphoblastic leukemia/lymphoblastic lymphoma, T-ALL/LBL) and mature T-cell neoplasms, which are comprised of 28 different entities. Most of these malignancies are aggressive with rather poor prognosis. Prognosis of relapsed/refractory (R/R) disease is especially dismal, with an expected survival only several months after progression. Targeted therapies, such as antiCD30 immunotoxin brentuximab vedotin, antiCD38 antibody daratumumab, and anti-CCR4 antibody mogamulizumab are effective only in subsets of patients with T-cell neoplasms. T-cells equipped with chimeric antigen receptor (CAR-Ts) are routinely used for treatment of R/R B-cell malignancies, however, there are specific obstacles for their use in T-cell leukemias and lymphomas which are fratricide killing, risk of transfection of malignant cells, and T-cell aplasia. The solution for these problems relies on target antigen selection, CRISPR/Cas9 or TALEN gene editing, posttranslational regulation of CAR-T surface antigen expression, and safety switches. Structural chromosomal changes and global changes in gene expression were observed with gene-edited products. We identified 49 studies of CAR-based therapies registered on www.clinicaltrials.gov. Most of them target CD30 or CD7 antigen. Results are available only for a minority of these studies. In general, clinical responses are above 50% but reported follow-up is very short. Specific toxicities of CAR-based therapies, namely cytokine release syndrome (CRS), seem to be connected with the antigen of interest and source of cells for manufacturing. CRS is more frequent in antiCD7 CAR-T cells than in antiCD30 cells, but it is mild in most patients. More severe CRS was observed after gene-edited allogeneic CAR-T cells. Immune effector cell associated neurotoxicity (ICANS) was mild and infrequent. Graft-versus-host disease (GvHD) after allogeneic CAR-T cells from previous hematopoietic stem cell donor was also observed. Most frequent toxicities, similarly to antiCD19 CAR-T cells, are cytopenias. CAR-based cellular therapy seems feasible and effective for T-cell malignancies, however, the optimal design of CAR-based products is still unknown and long-term follow-up is needed for evaluation of their true potential.

Chidamide combined with traditional chemotherapy for primary cutaneous aggressive epidermotropic CD8+ cytotoxic T-cell lymphoma: A case report

BACKGROUND

Traditional chemotherapy has benefited many patients with non-Hodgkin's lymphoma, but results in a very poor response in patients with rare lymphomas or refractory lymphomas. Previous studies have shown that chidamide has potential anti-lymphoma activity and reverses lymphoma cell chemoresistance to increase the chemosensitivity of lymphoma cells to traditional chemotherapy.

CASE SUMMARY

A 14-year-old boy was admitted to our hospital with a 5-d history of generalized erythema, papules, and blisters. Initially, the disease was refractory to potent anti-allergic and anti-infective treatment, and his condition progressively worsened. Skin biopsy revealed primary cutaneous aggressive epidermotropic CD8+ cytotoxic T-cell lymphoma. Considering that the disease is extremely rare in clinical practice, existing case reports have shown poor efficacy with traditional chemotherapy alone. We recommend chidamide combined with traditional chemotherapy for treatment. The regimen was as follows: Chidamide 30 mg/biw, cyclophosphamide 1100 mg/d1, pirarubicin 70 mg/d1, vincristine 2 mg/d1, dexamethasone 20 mg/d1-5, etoposide 100 mg/d1-5, in a 21 d cycle. The treatment effect was considerable, and complete remission was achieved after 4 cycles of treatment, after which the patient completed a total of 6 cycles of treatment. Subsequently, the patient regularly took chidamide 20 mg/biw as maintenance therapy for 1 year. To date, the patient has been disease-free for 3 years.

CONCLUSION

This case suggests that the combination of chidamide and traditional chemotherapy is effective in primary cutaneous aggressive epidermotropic CD8+ cytotoxic T-cell lymphoma.

Cutaneous T cell lymphoma

Primary cutaneous T cell lymphomas (CTCLs) are a heterogeneous group of lymphomas that present in the skin with no evidence of extracutaneous disease at the time of diagnosis. CTCL subtypes demonstrate a variety of clinical, histological, and molecular features, and can follow an indolent or a very aggressive course. The underlying pathogenetic mechanisms are not yet entirely understood. The pathophysiology of CTCL is complex and a single initiating factor has not yet been identified. Diagnosis is based on clinicopathological correlation and requires an interdisciplinary team. Treatment decision is made based on short-term and long-term goals. Therapy options comprise skin-directed therapies, such as topical steroids or phototherapy, and systemic therapies, such as monoclonal antibodies or chemotherapy. So far, the only curative treatment approach is allogeneic haematopoietic stem cell transplantation. Novel therapies, such as chimeric antigen receptor T cells, monoclonal antibodies or small molecules, are being investigated in clinical trials. Patients with CTCL have reduced quality of life and a lack of effective treatment options. Further research is needed to better identify the underlying mechanisms of CTCL development and course as well as to better tailor treatment strategies to individual patients.

Outcomes and prognostic factors in canine epitheliotropic and nonepitheliotropic cutaneous T-cell lymphomas

Canine cutaneous lymphoma is an uncommon lymphoma in dogs. Most canine cutaneous lymphoma cases have a T-cell origin. Canine cutaneous T-cell lymphoma (CTCL) is classified into epitheliotropic and nonepitheliotropic cutaneous lymphomas, and each type of lymphoma is subclassified into several histological subtypes. Limited information is available regarding the prognostic significance of clinical variables and histopathological subtypes in dogs with CTCL. This retrospective study aimed to investigate the influence of clinical variables and histopathological subtypes on the prognosis of dogs with CTCL. Forty-six dogs diagnosed with CTCL by histopathological examination were included. Histopathological specimens were reexamined and classified into CTCL subtypes. The influence of the type of skin lesion, histopathological subtype, haematological examination results and treatment response on the overall survival time (OS) was examined. Thirty-one dogs were diagnosed with epitheliotropic CTCL (mycosis fungoides in 28 dogs; pagetoid reticulosis in 3 dogs) and 15 dogs were diagnosed with nonepitheliotropic CTCL (anaplastic large T-cell lymphoma in 6 dogs; peripheral T-cell lymphoma, not otherwise specified, in 9 dogs). The OS of dogs diagnosed with epitheliotropic CTCL (141 days) was significantly shorter than that of dogs diagnosed with nonepitheliotropic CTCL (374 days). As clinical variables, the presence of neoplastic lymphocytes in peripheral blood, thrombocytopenia and initial chemotherapeutic response was related to prognosis. Our results demonstrated that histopathological subtype and several clinical variables were found to influence the prognosis of dogs with CTCL.

Indolent CD8+ primary cutaneous T-cell lymphoma involving the eyelid of an adolescent

Primary cutaneous acral CD8+ T-cell lymphoma (PCACTL) is currently a provisional entity defined as a rare cutaneous proliferation of atypical CD8+ lymphocytes that preferentially involves acral sites and has a good prognosis. We present a case of primary cutaneous CD8+ T-cell lymphoma involving the eyelid of an adolescent male. The case shares features with PCACTL, including indolent clinical behavior and expression of CD68 in a Golgi-associated dot-like pattern; however, other features differ significantly from PCACTL as currently defined by the World Health Organization (WHO). These features include ulceration, expression of CD56, granzyme B, and perforin, and a high proliferative index. Given these discrepancies, our case is currently best classified as a CD8+ primary cutaneous peripheral T-cell lymphoma, not otherwise specified. We review the differential diagnosis for this case and suggest expanding the definition of PCACTL.

Gamma/Delta Phenotype in Primary Cutaneous T-cell Lymphomas and Lymphoid Proliferations: Challenges for Diagnosis and Classification

Primary cutaneous T-cell lymphomas pose a diagnostic challenge for dermatopathologists, hematopathologists, and general surgical pathologists. Recognition of gamma/delta phenotype in cutaneous T proliferations has been enhanced by the availability of antibodies against TCRgamma and delta for immunohistochemistry. Thus, reporting gamma/delta phenotype in a cutaneous T-cell lymphoid proliferation may indicate a significant change in therapy and a challenge for dermatologists and oncologists who treat these patients. Herein, we discuss primary cutaneous gamma/delta T-cell lymphoma, its differential diagnosis, and other skin lymphoid proliferations that may show gamma/delta phenotype. Awareness of the occurrence of gamma/delta phenotype in both T-cell lymphomas and benign lymphoid proliferations involving skin is crucial for a better interpretation of histopathologic findings. Integration of clinical presentation, morphology, immunoprofile, and molecular findings is key for a correct diagnosis and appropriate therapy of lesions displaying gamma/delta T-cell phenotype.

Long-Term Remission After Matched Sibling Donor Hematopoietic Cell Transplantation in a Patient With Primary Cutaneous CD8+ Aggressive Epidermotropic Cytotoxic T-Cell Lymphoma

Primary cutaneous CD8+ aggressive epidermotropic cytotoxic T-cell lymphoma (CD8+ PCAECTL) is an extremely rare neoplasm with a poor prognosis. Chemotherapy typically does not result in a sustained response, and hematopoietic stem cell transplant (HSCT) is the only therapy that has been shown to produce a durable response of any kind. Here, we report a case of a 25-year-old previously healthy male who presented with a painful ulcerative lesion on the bottom of his right great toe and local lymphadenopathy. The biopsy of the lesion was consistent with CD8+ PCAECTL. He received immediate chemotherapy followed by matched related donor HSCT (MRD-HSCT) and remained in complete remission (CR) for eight years post-transplant, longer than any CR reported in the literature. In conclusion, our report provides clinical evidence that early transplant consult and donor search is one of the key factors in the management of CD8+ PCAECTL.

Vulvar Primary Cutaneous CD8+ Aggressive Epidermotropic Cytotoxic T-Cell Lymphoma

Cutaneous T-cell lymphomas may present with a clinical course that is incongruent with the associated histologic findings. Primary cutaneous CD8+ aggressive epidermotropic cytotoxic T-cell lymphoma classically presents as an abrupt eruption of disseminated ulcerated annular plaques with aggressive behavior and a poor prognosis. Herein we describe a vulvar primary cutaneous CD8+ aggressive epidermotropic cytotoxic T-cell lymphoma with a locally aggressive clinical course that was strikingly responsive to radiation therapy. As aggressive therapy involving systemic chemotherapy is indicated for primary cutaneous CD8+ aggressive epidermotropic cytotoxic T-cell lymphoma, appropriate clinico-pathologic correlation is crucial for preventing potentially excessive or insufficient therapeutic intervention. Our case also highlights the pivotal role of both radiation therapy and infection control in the management of aggressive cutaneous vulvar lymphomas.

Article Topic/Title: Primary cutaneous T-cell lymphomas other than Mycosis Fungoides and Sezary Syndrome. Part II: Prognosis and Management

Primary cutaneous T-cell lymphomas (CTCLs) other than Mycosis Fungoides (MF) and Sézary syndrome (SS) encompass a heterogenous group of non-Hodgkin lymphomas with variable clinical course, prognoses, and management. With morphologic and histologic overlap among the CTCL subtypes and other T-cell lymphomas with cutaneous manifestations, thorough evaluation with clinicopathologic correlation and exclusion of systemic involvement are essential prior to initiating therapy. Staging and treatment recommendations vary depending on the subtype, clinical behavior, and treatment response. Generally, for subtypes where staging is recommended, Ann Arbor or TNM staging specific to CTCL other than MF or SS are used. For many subtypes, there is no standard treatment to date. Available recommended treatments range widely from no active or minimal intervention with skin-directed therapy to aggressive systemic therapies including multiagent chemotherapy with consideration for hematopoietic stem cell transplant. Emerging targeted therapies, such as brentuximab, a chimeric antibody targeting CD30, show promise in altering the disease course of non-MF/SS CTCLs.

Primary cutaneous T-cell lymphomas other than Mycosis Fungoides and Sezary Syndrome - Part I: Clinical and histologic features and diagnosis

Primary cutaneous T-cell lymphomas (CTCLs) are defined as lymphomas with a T-cell phenotype that present in the skin without evidence of systemic or extracutaneous disease at initial presentation. CTCLs other than Mycosis Fungoides (MF) and Sézary syndrome (SS) account for approximately one-third of CTCLs and encompass a heterogenous group of non-Hodgkin lymphomas ranging from indolent lymphoproliferative disorders to aggressive malignancies with a poor prognosis. The spectrum of CTCLs continues to broaden as new provisional entities are classified. Given the morphologic and histologic overlap among CTCLs and other diagnoses, a thorough clinical history, physical evaluation, and clinicopathologic correlation are essential in the workup and diagnosis of these rare entities. This article will summarize the epidemiologic, clinical, pathologic, and diagnostic features of CTCLs other than MF and SS.

Immunophenotypic switch in cutaneous T-cell lymphoma: A series of three cases and review of the literature

Primary cutaneous T-cell lymphoma (CTCL) comprises a heterogeneous group of neoplasms with variable clinical behavior. Immunophenotypic switch (IS) is a phenomenon that occurs during lymphoma progression and is defined by an alteration in the immunophenotypic expression of a tumor with retention of its genotypic signature. This has been well-recognized in hematopoietic neoplasms; however, it has been rarely reported in CTCL and its clinical implications are not well understood. We present the clinical, histopathologic, immunophenotypic, and genetic findings of three cases of CTCL that demonstrated IS post treatment with variable outcomes. We add our cases to the small number previously reported to increase awareness of this phenomenon and its diagnostic challenge.

High incidence of adnexotropism in cytotoxic cutaneous lymphomas

BACKGROUND

Primary cutaneous gamma-delta T-cell lymphoma (PCγδTCL) and primary cutaneous aggressive epidermotropic T-cell lymphomas (PCAETCL) are rare aggressive cytotoxic cutaneous lymphomas (CyCL) often difficult to diagnose. Histopathologically, PCAETCL and PCγδTCL may resemble mycosis fungoides (MF) and the presence of adnexotropism in CyCL (CyCL) contributes to this diagnostic challenge, especially in the setting of atypical and double-negative phenotypes.

METHODS

In this retrospective study clinical data and histopathological section of 91 patients were analyzed for signs of clinical and histopathological signs adnexotropism.

RESULTS

Adnexotropism was identified in 48.4% (44/91) of cases, including PCAETCL (40.9%, 18/44), PCγδTCL and cytotoxic cutaneous lymphomas, not otherwise specified (CyCTCL, NOS) (43.2%, 19/44 and 15.9%, 7/44). Comparison between disease-related mortality with Kaplan-Meier survival analysis of non-adnexotropic vs adnexotropic CyCL did not show any significant difference between the two groups (P = 0.8). Clinically they present with patches, plaques, and tumors and commonly with ulceration, but follicular prominence or alopecia are rare. Clinical signs of adnexotropism such as alopecia and hypo- or anhidrosis were rarely seen.

CONCLUSION

Adnexotropism is a common finding in CyCL, especially in PCAETCL. Adnexotropic CyCL may be histopathologically difficult to distinguish from folliculotropic mycosis fungoides. A comprehensive IHC panel should be routinely performed in such cases.

Aggressive CD4/CD8 Double-Negative Primary Cutaneous T-Cell Lymphoma With Dural Invasion: A Rare Presentation of Mycosis Fungoides?

ABSTRACT

Mycosis fungoides (MF) is primarily characterized by epidermotropic CD3+/CD4+/CD45RO+ memory T cells. CD4/CD8 double-negative MF is an uncommon variant with no presumed prognostic significance. Despite the variability in the clinical course and presentation of MF, most cases behave indolently. About 5% of patients, however, advance to stage IV with visceral organ involvement. Central nervous system metastasis in MF is rare with no known cases of direct central nervous system invasion by MF to date. We report an exceedingly rare locally aggressive case of CD4/CD8 double-negative MF with direct dural invasion and underline pertinent diagnostic challenges encountered in our case.

Monomorphic Epitheliotropic Intestinal T-Cell Lymphoma With Secondary Cutaneous Involvement: A Diagnostic Challenge

ABSTRACT

A 45-year-old woman presented with a solitary breast nodule that histologically corresponded to a dense dermal/subcutaneous infiltration of atypical cytotoxic T-lymphocytes (CD3+, CD8+, CD56+, TIA-1+, CD5-, CD4-, CD30-, EBV-), resembling subcutaneous panniculitic T-cell lymphoma. The presence of TCRδ gene rearrangement and the absence of βF1 expression let to suspect the diagnosis of primary cutaneous γδT-cell lymphoma. As a consequence of jejunum perforation following chemotherapy treatment, a mucosal atypical lymphoid infiltration with marked epitheliotropism was observed in the resected intestinal sample, and the diagnosis of monomorphic epitheliotropic intestinal T-cell lymphoma (MEITL) was finally established. Disease progression appeared with multiple erythematous plaques showing a dense lichenoid atypical cytotoxic T-cell infiltrate with intense epidermotropism, mimicking primary cutaneous epidermotropic aggressive CD8+ T-cell lymphoma. MEITL is an uncommon and aggressive peripheral T-cell lymphoma that often presents in adults with gastrointestinal symptoms. Secondary cutaneous involvement is a rare phenomenon that may show clinicopathologic and immunohistochemical features that overlap with different subtypes of primary cutaneous cytotoxic T-cell lymphomas. In the absence of gastrointestinal symptoms, the diagnosis may be challenging, and only the evidence of underlying MEITL may allow to establish the definite diagnosis.

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).

[Facial ulcerated nodules revealing primary cutaneous CD8-positive aggressive epidermotropic cytotoxic T-cell lymphoma]

BACKGROUND

Primary cutaneous CD8+ aggressive, epidermotropic, cytotoxic T-cell lymphoma is a rare disease with a poor prognosis. Herein we report a new case, with facial lesions, which was difficult to diagnose.

PATIENTS AND METHODS

A 39-year-old woman was hospitalized for ulcerated nodules on the face that had been developing rapidly for 8 weeks. She had visited Djerba, Tunisia, 3 months earlier. No abnormalities were found on previous routine blood tests. Histopathological analysis of a skin biopsy had revealed non-specific lymphocytic infiltrate. Various therapies, including amoxicillin/clavulanic acid, valaciclovir, corticosteroids, colchicine and doxycycline, proved ineffective. Screening of the cutaneous sample for leishmaniasis proved positive using PCR but negative by direct examination and culture. Treatment was initiated with meglumine antimoniate. A further cutaneous biopsy revealed diffuse lymphocytic proliferation and led to a diagnosis of cutaneous CD8+ aggressive, epidermotropic, cytotoxic T-cell lymphoma. A PET scan showed multiple sites of hypermetabolism affecting the face and lymph nodes. Meglumine antimoniate was stopped and the patient experienced complete remission after chemotherapy.

CONCLUSION

Ulcerated nodules with acute progression on acral sites are characteristic of cutaneous CD8+ aggressive, epidermotropic, cytotoxic T-cell lymphoma. In our case, the positive result of PCR screening for Leishmania that was ultimately considered a false positive was a confounding factor in the diagnostic process. Regarding therapy, aggressive treatment strategies such as multiagent chemotherapy and hematopoietic stem-cell transplantation are needed due to the rapid progression of the lymphoma.

A Systematic Approach to the Cutaneous Lymphoid Infiltrates: A Clinical, Morphologic, and Immunophenotypic Evaluation

CONTEXT.—

The evaluation of cutaneous lymphoid infiltrates, both neoplastic and inflammatory, occurs very frequently in routine dermatopathologic examination and consultation practices. The "tough" cutaneous lymphoid infiltrate is feared by many pathologists; skin biopsies are relatively small, whereas diagnostic possibilities are relatively broad. It is true that cutaneous lymphomas can be difficult to diagnose and that in many circumstances multiple biopsies are required to establish a correct diagnostic interpretation. As a reminder, one should understand that low-grade cutaneous lymphomas are indolent disorders that usually linger for decades and that therapy does not result in disease cure. It is also important to remember that in most circumstances, those patients will die from another process that is completely unrelated to a diagnosis of skin lymphoma (even in the absence of specific therapy).

OBJECTIVE.—

To use a clinicopathologic, immunophenotypic, and molecular approach in the evaluation of common lymphocytic infiltrates.

DATA SOURCES.—

An in-depth analysis of updated literature in the field of cutaneous lymphomas was done, with particular emphasis on updated terminology from the most recent World Health Organization classification of skin and hematologic tumors.

CONCLUSIONS.—

A diagnosis of cutaneous lymphoid infiltrates can be adequately approached using a systematic scheme following the proposed ABCDE system. Overall, cutaneous T- and B-cell lymphomas are rare and "reactive" infiltrates are more common. Evaluation of lymphoid proliferations should start with a good sense of knowledge of the clinical presentation of the lesions, the clinical differential considerations, and a conscientious and appropriate use of immunohistochemistry and molecular tools.