Primary Cutaneous Acral CD8-Positive Lymphoproliferative Disorder: A Case Report With Nonacral Presentation

In this study, we describe a patient of primary cutaneous acral CD8-positive lymphoproliferative disorder located in a nonacral region. A 65-year-old male presented with an ill-defined lesion of rubbery consistency and a maximum diameter of 2.5 cm localized in the right thigh. Histologically, it was composed of a diffuse dermal infiltration of medium-sized atypical lymphocytes that expressed CD3, CD8, and TIA-1. In addition, a characteristic paranuclear positivity with CD68 was observed. During the follow-up, the patient had a recurrence of the disease in the abdomen with a lesion showing similar morphology and phenotype. To our knowledge, < 20 patients of primary cutaneous acral CD8-positive lymphoproliferative disorder with a nonacral presentation have been described in English literature. Although rare, its identification is essential to differentiate it from other T-cell lymphoma that express CD8 and cytotoxic markers, and whose clinical courses are very aggressive.

The enigmatic ear: Unveiling a rare case of a primary cutaneous CD8+ acral T-cell lymphoproliferative disorder with a literature review

Introduction: Primary cutaneous CD8+ acral T-cell lymphoproliferative disorder (CD8+ ATCLPD) is a rare form of cutaneous T-cell lymphoma that commonly presents on the acral regions of the body. We report a case of a 61-year-old man diagnosed with primary cutaneous CD8+ ATCLPD of the ear. Case presentation: A 61-year-old man presented with a non-healing, erythematous painful macule on the ear that had been evolving for the past 3 months. The lesion was resected, and histopathological examination revealed a primary cutaneous CD8+ ATCLPD with acral localization. Further investigations including CT scan of the thorax, abdomen and pelvis were done to stage the disease. The results showed no extracutaneous involvement. Conclusion: Accurate identification of primary cutaneous CD8+ ATCLPD is crucial due to its distinct prognostic and therapeutic implications compared to other CD8+ cytotoxic lymphoid proliferations. Primary cutaneous CD8+ ATCLPD can be treated conservatively and typically follows a slow clinical course, regardless of the treatment method. Understanding the clinical context, as well as the morphological and immunophenotypic characteristics, can assist in making a precise diagnosis.

Molecular pathogenesis of Cutaneous T cell Lymphoma: Role of chemokines, cytokines, and dysregulated signaling pathways

Cutaneous T cell lymphomas (CTCLs) are a heterogeneous group of lymphoproliferative neoplasms that exhibit a wide spectrum of immune-phenotypical, clinical, and histopathological features. The biology of CTCL is complex and remains elusive. In recent years, the application of next-generation sequencing (NGS) has evolved our understanding of the pathogenetic mechanisms, including genetic aberrations and epigenetic abnormalities that shape the mutational landscape of CTCL and represent one of the important pro-tumorigenic principles in CTCL initiation and progression. Still, identification of the major pathophysiological pathways including genetic and epigenetic components that mediate malignant clonal T cell expansion has not been achieved. This is of prime importance given the role of malignant T cell clones in fostering T helper 2 (Th2)-bias tumor microenvironment and fueling progressive immune dysregulation and tumor cell growth in CTCL patients, manifested by the secretion of Th2-associated cytokines and chemokines. Alterations in malignant cytokine and chemokine expression patterns orchestrate the inflammatory milieu and influence the migration dynamics of malignant clonal T cells. Here, we highlight recent insights about the molecular mechanisms of CTCL pathogenesis, emphasizing the role of cytokines, chemokines, and associated downstream signaling networks in driving immune defects, malignant transformation, and disease progression. In-depth characterization of the CTCL immunophenotype and tumoral microenvironment offers a facile opportunity to expand the therapeutic armamentarium of CTCL, an intractable malignant skin disease with poor prognosis and in dire need of curative treatment approaches.

Clinical, histopathological and prognostic features of primary cutaneous acral CD8+ T-cell lymphoma and other dermal CD8+ cutaneous lymphoproliferations - Results of an EORTC Cutaneous Lymphoma Group Workshop

BACKGROUND

The differential diagnosis of atypical dermal non-epidermotropic CD8+lymphocytic infiltrates includes a heterogenous spectrum of lymphoproliferations with overlapping histological and phenotypic features, but divergent clinical manifestations and prognoses. As these neoplasms are rare, more data on their clinicopathological presentation and course are needed.

OBJECTIVES

To assess the clinical, histological, immunophenotypic features, outcome of and differences between dermal CD8+ lymphoproliferations.

METHODS

Retrospective analysis of a series of 47 patients and biopsies by the international EORTC Cutaneous Lymphoma Group.

RESULTS

The dermal CD8+ lymphoproliferations (n=46) could be assigned to one of the following 3 groups: (1) cutaneous acral CD8+ T-cell lymphoma (n=31), characterized mostly by a solitary nodule arising at acral sites, a monotonous dermal infiltrate of small to medium-sized CD8+ lymphocytes with a characteristic dot-like pattern of CD68, a low proliferation rate and an excellent prognosis; (2) primary cutaneous CD8+ peripheral T-cell lymphoma, unspecified/NOS (n=11), presenting with one or multiple rapidly evolving tumors, mostly medium-sized pleomorphic CD8+ tumor cells with expression of several cytotoxic markers and high proliferative activity. After chemotherapy or radiotherapy relapses occurred in one third and 1 of 11 patients died due to lymphoma (9%); (3) The third group (n=4) comprised cutaneous CD8+ lymphoproliferations associated with congenital immunodeficiency syndromes in 2 patients with persisting localized or disseminated violaceous to brownish plaques on the extremities, a histiocyte-rich infiltrate of mostly small CD8+ lymphocytes with subtle atypia and a protracted course, and papular CD8+ eruptions in two patients with acquired immunosuppression (HIV-infection, solid organ transplantation).

CONCLUSIONS

A constellation of distinct clinical, histopathologic and phenotypic features allows discrimination and assignment of dermal CD8+ infiltrates to distinct disease entities including cutaneous acral CD8+ T-cell lymphoma, primary cutaneous CD8+ peripheral T-cell lymphoma, unspecified/NOS and cutaneous CD8+ lymphoproliferations associated with congenital or acquired immunodeficiency syndromes. Primary cutaneous acral CD8+ lymphoma, assigned a provisional category in current lymphoma classifications, is a distinct and reproducible entity. A correct diagnosis is essential to avoid unnecessarily aggressive treatment for indolent CD8+ lymphoproliferations and to identify cases with underlying immunodeficiency or potential for dismal outcome.

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.

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.

Atypical BCL6/GATA3+ Primary Cutaneous Acral CD8-Positive T-Cell Lymphoma: A Diagnostic Challenge

ABSTRACT

Primary cutaneous acral CD8-positive T-cell lymphoma consists of slow-growing nodules in acral sites with a histopathology, suggesting high-grade lymphoma despite the indolent clinical course. It has been recently included in WHO-EORTC classification for primary cutaneous lymphomas as a provisional entity. A correct diagnosis of this entity is important because its differential diagnosis include more aggressive cutaneous lymphomas. We present a 53-year-old woman with an indolent solitary nodule on her right leg, which histopathologically showed features of CD8-positive T-cell lymphoma, although with some peculiarities, including epidermotropism, absence of CD68 expression, and positivity for GATA3 and Bcl6 in neoplastic cells. This case could contribute to better define the spectrum of this rare cutaneous lymphoma.

Overview of Cutaneous T-Cell Lymphomas

Non-Hodgkin's lymphoma (NHL) encompasses a diverse collection of systemic and primary cutaneous lymphomas. Cutaneous T-cell lymphomas (CTCLs) represent about 13% of all NHLs, which are further subdivided into a heterogeneous group with vastly different presentations and histologic features. Diagnosis requires integration of clinical, pathologic, and molecular features. Among CTCLs, mycosis fungoides and Sézary syndrome are the most prevalent. Treatment is aimed at limiting morbidity and halting disease progression. Hematopoietic stem cell transplantation is the only therapy with curative intent.

The 2017 WHO update on mature T- and natural killer (NK) cell neoplasms

Over the last decade, there has been a significant body of information regarding the biology of the lymphoid neoplasms. This clearly supports the need for updating the 2008 WHO (World Health Organization) classification of haematopoietic and lymphoid tumours. The 2017 WHO classification is not a new edition but an update and revision of the 4th edition. New provisional entities but not new definitive entities are included, and novel molecular data in most of the entities and changes in the nomenclature in few of them have been incorporated. In the context of the mature T- and NK-cell neoplasms, the most relevant updates concern to: 1-dysregulation of the JAK/STAT pathway due to gene mutations which are common to various aggressive and indolent neoplasms; 2-incorporation of new molecular players that are relevant to the pathogenesis of these neoplasms and/or have prognostic implications; 3-inclusion of new provisional entities within the subgroups of anaplastic, primarily intestinal and cutaneous lymphomas such as breast implant-associated anaplastic large cell lymphoma, indolent T-cell lymphoproliferative disorder of the gastrointestinal tract and primary cutaneous acral CD8⁺ T-cell lymphoma; 4-identification of poor prognostic subtypes of peripheral T-cell lymphomas not otherwise specified (PTCL, NOS) characterized by overexpression of certain genes and of a subgroup PTCL, NOS with a T follicular phenotype that now is included together with angioimmunoblastic T-cell lymphoma under the umbrella of lymphomas with a T follicular helper phenotype; and 5-refinement on the designation and definition of already established entities. A review of the major changes will be outlined.

New Therapies and Immunological Findings in Cutaneous T-Cell Lymphoma

Primary cutaneous lymphomas comprise a group of lymphatic malignancies that occur primarily in the skin. They represent the second most common form of extranodal non-Hodgkin’s lymphoma and are characterized by heterogeneous clinical, histological, immunological, and molecular features. The most common type is mycosis fungoides and its leukemic variant, Sézary syndrome. Both diseases are considered T-helper cell type 2 (Th2) diseases. Not only the tumor cells but also the tumor microenvironment can promote Th2 differentiation, which is beneficial for the tumor cells because a Th1 environment enhances antitumor immune responses. This Th2-dominant milieu also underlies the infectious susceptibility of the patients. Many components, such as tumor-associated macrophages, cancer-associated fibroblasts, and dendritic cells, as well as humoral factors, such as chemokines and cytokines, establish the tumor microenvironment and can modify tumor cell migration and proliferation. Multiagent chemotherapy often induces immunosuppression, resulting in an increased risk of serious infection and poor tolerance. Therefore, overtreatment should be avoided for these types of lymphomas. Interferons have been shown to increase the time to next treatment to a greater degree than has chemotherapy. The pathogenesis and prognosis of cutaneous T-cell lymphoma (CTCL) differ markedly among the subtypes. In some aggressive subtypes of CTCLs, such as primary cutaneous gamma/delta T-cell lymphoma and primary cutaneous CD8⁺ aggressive epidermotropic cytotoxic T-cell lymphoma, hematopoietic stem cell transplantation should be considered, whereas overtreatment should be avoided with other, favorable subtypes. Therefore, a solid understanding of the pathogenesis and immunological background of cutaneous lymphoma is required to better treat patients who are inflicted with this disease. This review summarizes the current knowledge in the field to attempt to achieve this objective.