Mast Cells Are Abundant in Primary Cutaneous T-Cell Lymphomas: Results from a Computer-Aided Quantitative Immunohistological Study

What's New in Cutaneous T-Cell Lymphoma-Associated Pruritus

Cutaneous T-cell lymphomas are a heterogenous group of lymphomas that cause various skin manifestations. Severe pruritus occurs frequently in cutaneous T-cell lymphoma and negatively impacts patients' quality of life. The pathophysiology of cutaneous T-cell lymphoma-associated itch is complex and involves various immune cells, inflammatory cytokines, and neuroimmune interactions. Treating cutaneous T-cell lymphoma pruritus can be challenging, and there have been few randomized controlled studies evaluating the use of antipruritic treatments in these patients. Systemic therapies targeting the disease have also been shown to have some antipruritic effects. Furthermore, although biologic therapy has revolutionized the treatment of other pruritic skin conditions, the use of biologics in cutaneous T-cell lymphoma remains controversial.

A Microenvironment-Related Nine-Gene Signature May Predict Survival in Mycosis Fungoides Patients at Diagnosis

Mycosis fungoides (MF) is the most common cutaneous lymphoma characterized by an indolent course. Prognosis is stage-based but this approach does not reflect the different outcomes within stages. Considering that tumor microenvironment is known to be involved in MF pathogenesis and progression, we decided to investigate 99 MF cases by using the PanCancer Immune Profiling Panel. We identified and validated a signature of 9 genes able to predict MF survival and distinguish a high-risk group with a worse outcome from a low-risk group of cases with a better outcome. At the molecular level, low-risk vs. high-risk cases reported a global upregulation of immune genes, enriched in cytokines, and a higher density of dendritic cells and mast cells, possibly associated with a more favorable clinical course.

Mycosis fungoides and Sézary syndrome – Review and outlook

Mycosis fungoides and Sézary syndrome are the most important representatives of the heterogeneous group of cutaneous T-cell lymphomas. The diseases are rare and the diagnosis, which always requires a clinical-pathological correlation, is often delayed, especially in early forms of mycosis fungoides. The prognosis of mycosis fungoides depends on its stage and is usually favorable in the early stages. Clinically relevant prognostic parameters are missing and their development is the subject of current clinical research. Sézary syndrome, characterized by initial erythroderma and blood involvement, is a disease with a high mortality rate, in which good responses can now be achieved in many cases with new treatment options. The pathogenesis and immunology of the diseases is heterogeneous, with recent results pointing primarily to changes in specific signal transduction pathways that may be suitable as future treatment targets. Current therapy for mycosis fungoides and Sézary syndrome is primarily palliative with topical and systemic options either used alone or in combination. Only with allogeneic stem cell transplantation durable remissions can be achieved in selected patients. Similar to other areas of oncology, the development of new therapies for cutaneous lymphomas is currently changing from relatively untargeted empiricism to disease-specific, targeted pharmacotherapy based on knowledge from experimental research.

Mycosis Fungoides and Sézary Syndrome: Microenvironment and Cancer Progression

Mycosis fungoides and Sézary syndrome are epidermotropic cutaneous lymphomas, and both of them are rare diseases. Mycosis fungoides is the most frequent primary cutaneous lymphoma. In about 25% of patients with mycosis fungoides, the disease may progress to higher stages. The pathogenesis and risk factors of progression in mycosis fungoides and Sézary syndrome are not yet fully understood. Previous works have investigated inter- and intrapatient tumor cell heterogeneity. Here, we overview the role of the tumor microenvironment of mycosis fungoides and Sézary syndrome by describing its key components and functions. Emphasis is put on the role of the microenvironment in promoting tumor growth or antitumor immune response, as well as possible therapeutic targets. We focus on recent advances in the field and point out treatment-related alterations of the microenvironment. Deciphering the tumor microenvironment may help to develop strategies that lead to long-term disease control and cure.

Deep learning as a new tool in the diagnosis of mycosis fungoides

Mycosis Fungoides (MF) makes up the most of the cutaneous lymphomas. As a malignant disease, the greatest diagnostical challenge is to timely differentiate MF from inflammatory diseases. Contemporary computational methods successfully identify cell nuclei in histological specimens. Deep learning methods are especially favored for such tasks. A deep learning model was used to detect nuclei Hematoxylin-Eosin(H-E) stained micrographs. Nuclear properties are extracted after detection. A multi-layer perceptron classifier is used to detect lymphocytes specifically among the detected nuclei. The comparisons for each property between MF and non-MF were carried out using statistical tests the results are compared with the findings in the literature to provide a descriptive analysis as well. Random forest classifier method is used to build a model to classify MF and non-MF lymphocytes. 10 nuclear properties were statistically significantly different between MF and non-MF specimens. MF nuclei were smaller, darker and more heterogenous. Lymphocyte detection algorithm had an average 90.5% prediction power and MF detection algorithm had an average 94.2% prediction power. This project aims to fill the gap between computational advancement and medical practice. The models could make MF diagnoses easier, more accurate and earlier. The results also challenge the manually examined and defined nuclear properties of MF with the help of data abundance and computer objectivity.

The Role of Tumor Microenvironment in the Pathogenesis of Sézary Syndrome

Sézary syndrome is an aggressive leukemic variant of cutaneous T-cell lymphomas, characterized by erythroderma, lymphadenopathy, and peripheral blood involvement by CD4+ malignant T-cells. The pathogenesis of Sézary syndrome is not fully understood. However, the course of the disease is strongly influenced by the tumor microenvironment, which is altered by a combination of cytokines, chemokines, and growth factors. The crosstalk between malignant and reactive cells affects the immunologic response against tumor cells causing immune dysregulation. This review focuses on the interaction of malignant Sézary cells and the tumor microenvironment.

The Role of Tumor Microenvironment in Mycosis Fungoides and Sézary Syndrome

Mycosis fungoides (MF) and Sézary syndrome (SS) are the most common subtypes of cutaneous T-cell lymphomas (CTCLs). Most cases of MF display an indolent course during its early stage. However, in some patients, it can progress to the tumor stage with potential systematic involvement and a poor prognosis. SS is defined as an erythrodermic CTCL with leukemic involvements. The pathogenesis of MF and SS is still not fully understood, but recent data have found that the development of MF and SS is related to genetic alterations and possibly to environmental influences. In CTCL, many components interacting with tumor cells, such as tumor-associated macrophages, fibroblasts, dendritic cells, mast cells, and myeloid-derived suppressor cells, as well as with chemokines, cytokines and other key players, establish the tumor microenvironment (TME). In turn, the TME regulates tumor cell migration and proliferation directly and indirectly and may play a critical role in the progression of MF and SS. The TME of MF and SS appear to show features of a Th2 phenotype, thus dampening tumor-related immune responses. Recently, several studies have been published on the immunological characteristics of MF and SS, but a full understanding of the CTCL-related TME remains to be determined. This review focuses on the role of the TME in MF and SS, aiming to further demonstrate the pathogenesis of the disease and to provide new ideas for potential treatments targeted at the microenvironment components of the tumor.

Steering Mast Cells or Their Mediators as a Prospective Novel Therapeutic Approach for the Treatment of Hematological Malignancies

Tumor cells require signaling and close interaction with their microenvironment for their survival and proliferation. In the recent years, Mast cells have earned a greater importance for their presence and role in cancers. It is known that mast cells are attracted towards tumor microenvironment by secreted soluble chemotactic factors. Mast cells seem to exert a pro-tumorigenic role in hematological malignancies with a few exceptions where they showed anti-cancerous role. This dual role of mast cells in tumor growth and survival may be dependent on the intrinsic characteristics of the particular tumor, differences in tumor microenvironment according to tumor type, and the interactions and heterogeneity of mediators released by mast cells in the tumor microenvironment. In many studies, Mast cells and their mediators have been shown to affect tumor survival and growth, prognosis, inflammation, tumor vascularization and angiogenesis. Modulating mast cell accumulation, viability, activity and mediator release patterns may thus be important in controlling these malignancies. In this review, we emphasize on the role of mast cells in lymphoid malignancies and discuss strategies for targeting and steering mast cells or their mediators as a potential therapeutic approach for the treatment of these malignancies.

Survey of Mast Cell Density in Transitional Cell Carcinoma

Background & Objective:

Transitional cell carcinoma (TCC) is the world's seventh most common tumor and forms more than 90% of urinary bladder tumors. Invasive tumors are associated with poor prognosis, even with surgical treatment and chemotherapy. Some studies have found that an increase in the number of mast cells in TCC is related to the tumor grade and its aggressiveness. This study investigated the relationship between mast cell density (MCD) and features of TCC (tumor stage, grade, prognosis, and recurrence).

Methods:

Fifty-one cases with TCC were selected, and MCD was determined by immunohistochemistry (IHC) and Giemsa staining. Mortality rate and tumor recurrence were recorded.

Results:

The MCD mean was higher in high-grade tumors than in low-grade tumors (in IHC method: 9.127 vs 5.296; in Giemsa method: 5.512 vs 2.608). Also, the MCD mean in dead patients was higher than in survived patients (in IHC method: 11.390 vs 6.211; in Giemsa method: 7.460 vs 3.35). Patients with tumor recurrence showed a higher MCD mean than those without recurrence (in IHC method: 9.395 vs 5.475; in Giemsa method: 5.715 vs 2.931).

Conclusion:

Using mast cell tryptase and Giemsa, MCD may be associated with a positive correlation with tumor grade in TCC. Correlations between MCD, recurrence, prognosis, and tumor stage are probably caused by the effect of tumor grade (all with P<0.05).

Differential expression of mast cell granules in samples of metastatic and non-metastatic colorectal cancer in patients

Various cell types participate in the tumor process, in which the mast cells have been described; however, the role they play in colorectal adenocarcinoma has not yet been fully understood. Therefore, the present work aimed to compare employing histochemistry and immunohistochemistry, the number of mast cells and the content of some cytoplasmic granules in moderately differentiated non-metastatic and metastatic colorectal adenocarcinoma, analyzing tissue samples from patients. Histochemical techniques with Toluidine Blue (TBO), Periodic Schiff Acid (PAS), Alcian Blue/Periodic Acid-Schiff (PAB) and Alcian Blue/Safranin (ABS); as well as immunohistochemical reactions with anti-antibodies anti-Tryptase and anti-Chymase were applied to quantify total mast cells and content of some cytoplasmic granules. Statistical analysis was performed using SPSS V22.0 software (p ≤ 0.05). The degree of positivity of the reaction and degranulation of mast cells was reported in percentages. In our results, we observed that there are differences in the quantity and histochemical composition of the granules of mast cells (metastatic group PAS and ABS comparing the TBO reaction), as well as in the immunohistochemical composition between Tryptase and Chymase and the number of degranulated cells in both study groups (74 % degranulated mast cells in the metastatic group, 66 % integrate mast cells in the non-metastatic group). Therefore, we consider that the differences may be some of the probable factors that lead to metastasis of colorectal adenocarcinoma.

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.

Role of Mast Cells in Shaping the Tumor Microenvironment

Early mast cell (MC) infiltration has been reported in a wide range of human and animal tumors particularly malignant melanoma and breast and colorectal cancer. The consequences of their presence in the tumor microenvironment (TME) or at their margins still remain unclear as it is associated with a good or poor prognosis based on the type and anatomical site of the tumor. Within the tumor, MC interactions occur with infiltrated immune cells, tumor cells, and extracellular matrix (ECM) through direct cell-to-cell interactions or release of a broad range of mediators capable of remodeling the TME. MCs actively contribute to angiogenesis and induce neovascularization by releasing the classical proangiogenic factors including VEGF, FGF-2, PDGF, and IL-6, and nonclassical proangiogenic factors mainly proteases including tryptase and chymase. MCs support tumor invasiveness by releasing a broad range of matrix metalloproteinases (MMPs). MC presence within the tumor gained additional significance when it was assumed that controlling its activation by tyrosine kinase inhibitors (imatinib and masitinib) and tryptase inhibitors (gabexate and nafamostat mesylate) or controlling their interactions with other cell types may have therapeutic benefit.