New aspects of the clinicopathological features and treatment of mycosis fungoides and Sézary syndrome

Role of IL-4 and IL-13 in Cutaneous T Cell Lymphoma

The interleukins IL-4 and IL-13 are increasingly recognized contributors to the pathogenesis of cutaneous T cell lymphomas (CTCLs), and their role in disease-associated pruritus is accepted. The prevailing Th2 profile in advanced CTCL underscores the significance of understanding IL-4/IL-13 expression dynamics from the early stages of disease, as a shift from Th1 to Th2 may explain CTCL progression. Targeted agents blocking key cytokines of type 2 immunity are established therapeutics in atopic disorders and have a promising therapeutic potential in CTCL, given their involvement in cutaneous symptoms and their contribution to the pathogenesis of disease. IL-4, IL-13, and IL-31 are implicated in pruritus, offering therapeutic targets with dupilumab, tralokinumab, lebrikizumab, and nemolizumab. This review analyzes current knowledge on the IL-4/IL-13 axis in mycosis fungoides and Sezary syndrome, the most common types of CTCL, examining existing literature on the pathogenetic implications with a focus on investigational treatments. Clinical trials and case reports are required to shed light on novel uses of medications in various diseases, and ongoing research into the role of IL-4/IL-13 axis blockers in CTCL therapy might not only improve the management of disease-related pruritus but also provide in-depth insights on the pathophysiologic mechanisms of CTCL.

Erythrodermic CD4/CD8 Double-Negative Mycosis Fungoides: A Case Report

Cutaneous T-cell lymphoma (CTCL) describes a group of lymphoproliferative disorders characterized by localization of neoplastic T lymphocytes to the skin. Mycosis fungoides (MF) represents the most common type of CTCL and accounts for ∼60% of all primary cutaneous lymphomas. Apart from the classic type of MF, many clinical and histopathologic variants have been described. The malignant lymphocytes in MF are usually CD3, CD4 and CD45RO positive and CD8 negative. An unusual immunohistochemical profile of a CD4-negative and CD8-positive mature T-cell phenotype has been reported in a minority of patients; up to 20% of early-stage MF demonstrates a CD8-positive phenotype. There are only a few cases of a double-negative CD4/CD8 MF phenotype reported in the literature. We present the case of a 60-year-old male presenting a double-negative CD4/CD8 MF phenotype.

Pruritus as a Distinctive Feature of Type 2 Inflammation

Pruritus is a common symptom of several skin diseases, both inflammatory and neoplastic. Pruritus might have a tremendous impact on patients’ quality of life and strongly interfere with sleep, social, and work activities. We review the role of type-2 inflammation and immunity in the pathogenesis of chronic pruritic conditions of the skin. Type 2 cytokines, including IL-4, IL-13, thymic stromal lymphopoietin, periostin, IL-31, IL-25, and IL-33 are released by mast cells, innate lymphoid cells 2, keratinocytes, and type 2 T lymphocytes, and are master regulators of chronic itch. These cytokines might act as direct pruritogen on primary sensory neurons (pruriceptors) or alter the sensitivity to other itch mediators Type 2 inflammation- and immunity-dominated skin diseases, including atopic dermatitis, prurigo nodularis, bullous pemphigoid, scabies, parasitic diseases, urticaria, and Sézary syndrome are indeed conditions associated with most severe pruritus. In contrast, in other skin diseases, such as scleroderma, lupus erythematosus, hidradenitis suppurativa, and acne, type 2 inflammation is less represented, and pruritus is milder or variable. Th2 inflammation and immunity evolved to protect against parasites, and thus, the scratching response evoked by pruritus might have developed to alert about the presence and to remove parasites from the skin surface.

Mycosis fungoides and gastric T-cell lymphoma: A case report

Mycosis fungoides (MF) is a cutaneous malignant lymphoma with an extended clinical course. MF presents in series of dermatological manifestations, beginning with patches and plaques of the skin, and eventually evolving into tumours. Often MF can occur for extended periods without worsening of external symptoms, while the disease advances internally in organs such as lymph nodes, liver, spleen, lung, bone marrow, gastrointestinal tract, pancreas and kidney. The present report presents a clinical case in which gastrointestinal symptomatology occurred a decade after the first dermatological manifestation. Immunohistochemical analysis of the skin, along with small bowel biopsies revealed evidence of gastric T-cell lymphoma. To the best of our knowledge, the present study is the first to describe such a case in the literature.

Two distinct variants of mycosis fungoides (MF): Folliculotropic MF and erythrodermic MF

Mycosis fungoides (MF) is the most frequent type of cutaneous T-cell lymphoma. Folliculotropic MF (fMF) and erythrodermic MF (eMF) are two distinct variants of MF. Both variants have been considered aggressive and most cases are less responsive to standard skin-directed therapies than classical MF. We, however, experienced many cases with fMF or eMF who showed indolent clinical courses. In this article, we reviewed 10 cases with fMF and 13 cases with eMF who came to our department between 2005 and 2017. In patients with fMF, monotherapy with topical corticosteroid was effective in two cases (20%) and ultraviolet phototherapy with oral retinoid controlled disease activity in two cases (20%). Five patients with eMF (38%) responded well to ultraviolet phototherapy. In conclusion, patients with early fMF and a subgroup of eMF patients have an indolent disease course, as was proposed among the specialists. Skin-directed therapies are preferable rather than aggressive treatment in those cases.