Cutaneous lymphoproliferative disorders: Back to the future

In the 1980s, immunohistochemistry and clonality analyses became instrumental in the recognition and definition of new types of cutaneous T-cell lymphoma (CTCL) and cutaneous B-cell lymphoma (CBCL) and the development of new classifications. By accepting loss of pan-T-cell antigens and clonal T-cell receptor gene rearrangements as important criteria to differentiate between benign and malignant T-cell proliferations, and monotypic immunoglobulin light-chain expression and clonal immunoglobulin gene rearrangements as crucial criteria to distinguish between benign and malignant B-cell proliferations, many cases, until then diagnosed as cutaneous lymphoid hyperplasia or pseudolymphoma, were reclassified as primary cutaneous CD4+ small/medium T-cell lymphoma (PCSM-TCL) or primary cutaneous marginal zone lymphoma (PCMZL), respectively. However, in recent years there is growing awareness that neither these immunohistochemical criteria nor demonstration of T-cell or B-cell clonality is specific for malignant lymphomas. In addition, many studies have reported that these low-grade malignant CTCL and CBCL have an indolent clinical behavior and an excellent prognosis with disease-specific survival rates of or close to 100%. As a result, recent classifications have downgraded several low-grade malignant cutaneous lymphomas to lymphoproliferative disorder (LPD). Both the 5th edition of the WHO classification (2022) and the 2022 International Consensus Classification (ICC) of mature lymphoid neoplasms reclassified PCSM-TCL as primary cutaneous CD4+ small/medium T-cell LPD and primary cutaneous acral CD8+ T-cell lymphoma as primary cutaneous acral CD8+ T cell LPD. While the 2022 ICC introduced the term "primary cutaneous marginal zone LPD," in the 5th edition of the WHO classification PCMZL is maintained. In this review we describe the background and rationale of the continually changing terminology of these conditions and discuss the clinical consequences of downgrading malignant lymphomas to LPDs.

Adrenal Insufficiency after Long-term use of Topical Glucocorticoids in Patients with Advanced Cutaneous T-cell Lymphomas: A Case Series

Abstract is missing (Short communication)

Application of Blood Lymphocyte Immunophenotype and TCR Gene Rearrangement in the Diagnosis of CTCL

BACKGROUND

The immunophenotype of peripheral blood lymphocytes and T-cell receptor (TCR) gene rearrangement of cutaneous T cell lymphoma (CTCL) patients were retrospectively analyzed to explore their value in the diagnosis of CTCL.

METHODS

A total of fifty patients' results were enrolled from 2013 to 2021, including 29 malignant skin disorders and 21 benign skin disorders. The immunophenotype of peripheral blood lymphocytes were analyzed by flow cytometry and TCR gene rearrangement was detected by capillary electrophoresis. Lymphocyte subsets, CD4/CD8 ratio, the percentage of CD3+CD4+CD7- cells and CD45RA/CD45RO ratio was calculated between malignant and benign skin disorders. Peripheral blood lymphocyte immunophenotype and TCR gene rearrangement was compared with skin biopsy to evaluate their sensitivity and specificity.

RESULTS

Lymphocyte subsets between malignant and benign groups have no significant difference in percentage of T cell (p > 0.05). The CD4/CD8 ratio is higher in patients with malignant lymphoma than the healthy range. The percentage of CD3+CD4+CD7- cells in malignant groups is higher than that in benign groups and CD45RA/ CD45RO ratio has significant difference between malignant and benign groups (p < 0.05). The sensitivity and specificity of TCR rearrangement for CTCL were 51.7% and 42.9%. The sensitivity and specificity of peripheral blood lymphocyte immunophenotype for CTCL were 44.8% and 33.3%. Combining the two methods, the sensitivity and specificity reached 69.0% and 38.1%, respectively.

CONCLUSIONS

CD4/CD8 ratio of lymphocyte subsets, the proportion of CD4+CD7-T cells and CD45RA/CD45RO ratio can effectively distinguish benign and malignant dermatosis. TCR rearrangement method combined with lymphocyte immunophenotype can improve the sensitivity and specificity of CTCL diagnosis.

Subcutaneous Panniculitis-Like T-Cell Lymphoma With Hemophagocytic Lymphohistiocytosis

Subcutaneous panniculitis-like T-cell lymphoma (SPTLP), a unique variant of primary cutaneous T-cell lymphomas, clinically mimics subcutaneous panniculitis. It is typified by the development of multiple plaques or subcutaneous erythematous nodules, predominantly on the extremities and trunk. Epidemiological findings reveal a greater incidence in females than males, affecting a wide demographic, including pediatric and adult cohorts, with a median onset age of around 30 years. Diagnosis of SPTLP is complex, hinging on skin biopsy analyses and the identification of T-cell lineage-specific immunohistochemical markers. Treatment modalities for SPTLP are varied; while corticosteroids may be beneficial initially for many patients, a substantial number require chemotherapy, especially in cases of poor response or relapse. Generally, SPTLP progresses slowly, yet approximately 20% of cases advance to hemophagocytic lymphohistiocytosis (HLH), often correlating with a negative prognosis. We report a case of a young male patient presenting with prolonged fever, multiple skin lesions accompanied by HLH, a poor clinical course, and eventual death, diagnosed postmortem with SPTLP. In addition, we also present a literature review of the current evidence of some updates related to SPTLP.

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.

Decrease of 5-hydroxymethylcytosine in primary cutaneous CD4+ small/medium sized pleomorphic T-cell lymphoproliferative disorder

BACKGROUND

Primary cutaneous CD4+ small/medium-sized pleomorphic T-Cell lymphoproliferative disorder (PC-SMTLD) has been considered as a controversial dermatological disease that has been included in cutaneous T-cell lymphoma group, presenting most commonly as a solitary nodule and/or plaque with a specific and characteristic head and neck predilection. Due to the considerable overlap between PC-SMTLD and pseudolymphoma (PL), the differential diagnosis is often challenging. Methylation of DNA at position 5 of cytosine, and the subsequent reduction in intracellular 5-hydroxymethylcytosine (5-hmC) levels, is a key epigenetic event in several cancers, including systemic lymphomas. However, it has rarely been studied in cutaneous lymphomas.

OBJECTIVES

The authors aimed to explore the role of differential 5-hmC immunostaining as a useful marker to distinguish PC-SMTLD from PL.

METHODS

Retrospective case series study with immunohistochemical and immunofluorescence analysis of 5-hmC was performed in PL and PC-SMTLD.

RESULTS

Significant decrease of 5-hmC nuclear staining was observed in PC-SMTLD when compared with PL (p < 0.0001). By semi-quantitative grade integration, there were statistical differences in the final 5-hmC scores in the two study groups. The IF co-staining of 5-hmC with CD4 revealed a decrease of 5-hmC in CD4+ lymphocytes of PC-SMTLD.

STUDY LIMITATIONS

The small clinical sample size of the study.

CONCLUSIONS

The immunorreactivity of 5-hmC in CD4+ lymphocytes was highly suggestive of a benign process as PL. Furthermore, the decrease of 5-hmC nuclear staining in PC-SMTLD indicated its lymphoproliferative status and helped to make the differential diagnosis with PL.

Immunosequencing applications in cutaneous T-cell lymphoma

Immunosequencing has emerged as a newer clinical test for assessment of T-cell clonality in the blood and skin of cutaneous T-cell lymphoma (CTCL) patients. Utilization of immunosequencing, also known as high-throughput sequencing of the T-cell receptor (HTS-TCR), enables identification and quantification of the precise genetic signature of dominant T-cell clones. Although immunosequencing is more sensitive than commonly used methods such as polymerase chain reaction (PCR) paired with capillary electrophoresis or flow cytometry, it remains underutilized for CTCL management. Nonetheless, incorporation of HTS-TCR in clinical practice offers distinct advantages compared to other molecular analyses that may improve diagnostic evaluation, prognostication, and disease monitoring in CTCL. The objective of this comprehensive review is to provide a thorough explanation of the application of immunosequencing in the context of CTCL. We describe the significance of T-cell clonality and the methods used to detect it, including a detailed comparison between PCR paired with capillary electrophoresis and HTS-TCR. The utilization of immunosequencing in the blood and skin of CTCL patients is discussed in depth, specifically outlining how HTS-TCR can assist in diagnosing CTCL, predicting outcomes, and tracking disease progression. Finally, we address the potential applications of immunosequencing in clinical management and research as well as the novel challenges it presents.

Cutaneous T-cell lymphoma with CNS involvement: a case series and review of the literature

Cutaneous T-cell lymphoma (CTCL) is a rare hematologic malignancy that traditionally presents with cutaneous lesions, though metastases are not uncommon in progressive disease. We describe four cases of CTCL with central nervous system (CNS) involvement, detailing the history, pathological characteristics, treatment response, and progression. Median time from initial diagnosis to CNS metastasis was ∼5.4 years (range 3.4-15.5 years) and survival after metastasis was ∼160 days (range 19 days-4.4 years). No patients achieved long-term (>5 years) survival, though some displayed varying degrees of remission following CNS-directed therapy. We conclude that clinicians must be attentive to the development of CNS metastases in patients with CTCL. The growing body of literature on such cases will inform evolving therapeutic guidelines on this rare CTCL complication.

DUSP22-IRF4 Rearranged CD30-Positive Primary Cutaneous Lymphoproliferative Disorder With Gamma/Delta Phenotype

ABSTRACT

CD30-positive primary cutaneous lymphoproliferative disorders (CD30 + PCLPD) are a heterogeneous group of cutaneous T-cell lymphoma (CTCL) that includes lymphomatoid papulosis (LyP) and primary cutaneous anaplastic large cell lymphoma. They exist as a clinical and pathological spectrum, which display significant overlap and variability. The diagnosis is made based on correlation between clinical and histopathologic findings. LyP with 6p25.3 rearrangement subtype represents <5% of LyP cases and is defined by DUSP22-IRF4 rearrangement on 6p25.3 locus. The reported cases express the alpha/beta T-cell receptor and follow an indolent clinical behavior typical of LyP. The same rearrangement is detected in 28% of anaplastic large cell lymphoma. We hereby present an extraordinary case of CD30 + PCLPD with DUSP22-IRF4 rearrangement and novel expression of gamma/delta T-cell immunophenotype in a young patient. Although the gamma/delta T-cell immunophenotype has been described in many other T-cell lymphomas, this is the first reported association with CD30 + PCLPD with DUSP22-IRF4 rearrangement.

Primary cutaneous T-cell lymphoma: a review of the most common entities with focus on recent updates

Cutaneous T-cell lymphomas are an heterogeneous group of uncommon lymphoid neoplasms that are challenging to diagnose and require close collaboration between dermatologists, pathologists and hematologists/oncologists. This article reviews the most common cutaneous T-cell lymphomas: mycosis fungoides (both classic and variant forms) as well as its leukemic counterpart Sézary syndrome, CD30+ T-cell lymphoproliferative disorders including the ever-expanding group of lymphomatoid papulosis and primary cutaneous anaplastic large cell lymphoma, and primary cutaneous CD4+ small/medium lymphoproliferative disorder. We discuss the classic clinical and histopathologic features of these lymphomas and review how they can be distinguished from reactive entities. In particularly, updates to these diagnostic categories and current controversies in classification are highlighted. Moreover, we review the prognosis and treatment for each entity. These lymphomas exhibit variable prognosis, and therefore it is important to correctly classify atypical cutaneous T-cell infiltrates for appropriate patient treatment and prognosis. Cutaneous T-cell lymphomas are at the interface of several medical specialties; this review seeks to summarize key features of these lymphomas and highlight new and emerging insights into these lymphomas.

Spatial transcriptomics reveals heterogeneity of macrophages in the tumor microenvironment of granulomatous slack skin

Granulomatous slack skin (GSS) is an extremely rare subtype of cutaneous T-cell lymphoma accompanied by an abundant number of macrophages and is clinically characterized by the development of pendulous skin folds. However, the characteristics of these macrophages in GSS remain unclear. Here, we conducted a spatial transcriptomic study on one frozen GSS sample and drew transcriptomic maps of GSS for the first time. Gene expression analysis revealed the enrichment of three clusters with macrophage transcripts, each exhibiting distinct characteristics suggesting that their primary composition consists of different subpopulations of macrophages. The CD163+ /CD206+ cluster showed a tumor-associated macrophage (TAM) M2-like phenotype and highly expressed ZFP36, CCL2, TNFAIP6, and KLF2, which are known to be involved in T-cell interaction and tumor progression. The APOC1+ /APOE+ cluster presented a non-M1 or -M2 phenotype and may be related to lipid metabolism. The CD11c+ /LYZ+ cluster exhibited an M1-like phenotype. Notably, these cells strongly expressed MMP9, MMP12, CHI3L1, CHIT1, COL1A1, TIMP1, and SPP1, which are responsible for extracellular matrix (ECM) degradation and tissue remodeling. This may partially explain the symptoms of cutaneous relaxation in GSS. Further immunohistochemistry on four GSS cases demonstrated that CD11c predominantly marked granulomas and multinucleated giant cells, whereas CD163 was mainly expressed on scattered macrophages, appearing as a mutually exclusive pattern. The expression pattern of MMP9 overlapped with that of CD11c, implying that CD11c+ macrophages may be a source of MMP9. Our data shed light on the characteristics of macrophages in the GSS microenvironment and provide a theoretical basis for the application of MMP9 inhibitors to prevent cutaneous relaxation of GSS. © 2023 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Clinical analysis of 20 cases of cutaneous extranodal NK/T-Cell lymphoma

Background To investigate the clinical features, pathological features and prognostic factors of cutaneous extranodal natural killer/T-cell lymphoma (CENKTL). Methods A total of 20 cases with CENKTL from February 2013 to November 2021 were analysed retrospectively. Results The patients included 15 men and five women, and their ages ranged from 19 to 92 (median age of 61) years. The most common lesions were on the extremities, followed by the trunk. Histopathological examination showed atypical lymphocyte infiltrate in dermis and subcutaneous fat. The tumour tissue showed vascular proliferation, vascular occlusion, and coagulation necrosis. In situ hybridisation revealed that 20 patients were positive for Epstein-Barr virus-coding ribonucleic acid. Immunohistochemistry showed that the tumour cells were positive for CD3 (18/20 and 90%), CD56 (19/20 and 95%), T-cell intracellular antigen (TIA-1) (13/14 and 92.9%) and CD20 (5/20, 25%). About 20 patients were positive for Ki-67 with values of 30-90%. A total of 11 of the 20 patients died, and two patients were lost to follow-up. The 2-year overall survival was 24%, and the median overall survival was 17 months. Univariate analysis revealed that involvement of lymph nodes (P = 0.042) correlated with worse survival. Limitation This is a retrospective study design and has a limited number of patients. Conclusion CENKTL is rare and has a poor prognosis. Diagnosis is challenging due to non-specific clinical symptoms and histopathology results. A comprehensive judgement should be made based on related clinical manifestations and histopathological and molecular examination. Lymph node involvement is an independent prognostic factor for CENKTL.

Characterizing Outcomes in Visceral Cutaneous T-Cell Lymphoma: A Single Center Retrospective Study

INTRODUCTION

Visceral involvement of cutaneous T-cell lymphoma (vCTCL) is a rare but poorly studied complication of CTCL. We aimed to assess clinical characteristics, treatment, and outcomes, associated with vCTCL at our institution.

METHODS

We conducted a retrospective review of patients with vCTCL among patients with a confirmed histopathologic diagnosis of CTCL seen at the Winship Cancer Institute in Emory University. vCTCL was defined as a highest TNMB stage of 4B with extracutaneous metastatic disease (M1) pathologically confirmed or strongly clinically suspected based on imaging, symptoms, and the clinical judgment of the treating physician. Patients were selected from our CTCL database containing 656 patients from 1990 to 2022. Clinical characteristics were characterized. Clinical outcomes were measured as overall survival (OS) and progression-free survival (PFS) using Kaplan-Meier curve and univariable Cox regression analysis.

RESULTS

Twenty-six of 656 patients with vCTCL were identified. 42.3% of patients were black. Twenty-two patients were diagnosed with MF/SS and 4 had other CTCL subtypes including pcALCL, Gamma-Delta, and Cytotoxic T-Cell Lymphoma. The median PFS and OS were 7.3 months (3.8, 11) and 12.1 months (9.9, 18.2), respectively. Median time to metastasis from initial diagnosis was 12.1 months. The most common M1 sites were liver (19.2%) and lung (42.3%). M1 sites outside of liver or lung were associated with inferior OS (HR 8.9, 95%CI: 2.7-29.5, P-value <.001) and PFS (HR 4.3, 95%CI: 1.44-12.7, P-value = .009). No treatments or baseline factors were associated with improved survival.

CONCLUSION

Our retrospective study confirms therapy resistance and dismal outcomes among patients with vCTCL.

Primary cutaneous lymphomas: exploration of 10-year data from supraregional mutlidisciplinary team meetings in Glasgow, UK

Primary cutaneous lymphomas (PCLs) are non-Hodgkin lymphomas, presenting in the skin. They are classified into cutaneous B-cell lymphomas (CBCLs) or cutaneous T-cell lymphomas (CTCLs). The most common CTCL subtypes are mycosis fungoides (MF) and Sézary syndrome (SS). All patient's cases should be discussed at a specialist multidisciplinary team (MDT) meeting. This is the first published review, to our knowledge, of PCL MDT case discussion in the UK. Patient cases between 2008 and 2019 were reviewed to assess: frequency of PCL subtype, documentation of CTCL staging and management of MF/SS. Of 356, 103 (29%) were CBCLs and the majority (n = 200, 56%) were CTCLs. MF/SS was the diagnosis in 120 (34%). Staging was documented in 44% (n = 53) of patients with MF/SS. Management largely followed guidelines for MF/SS, topical corticosteroids were the most common treatment (n = 93, 78%). Frequency of PCL subtype is largely comparable with previously published data. Documentation of CTCL staging is low, but higher than other reports. Our work begins to address the gap in real-world data on CTCLs. A standardized approach to data collection would inform clinical practice.

Chronic Obstructive Pulmonary Disease and Risk of Cutaneous T-cell Lymphoma: A Danish Population-based Cohort Study

Abstract is missing (Short communication)

Molecular techniques drive cutting edge advancements in management of cutaneous T cell lymphoma

Cutaneous 5T cell lymphoma (CTCL), characterized by malignant T cells infiltrating the skin with potential for dissemination, remains a challenging disease to diagnose and treat due to disease heterogeneity, treatment resistance, and lack of effective and standardized diagnostic and prognostic clinical tools. Currently, diagnosis of CTCL practically relies on clinical presentation, histopathology, and immunohistochemistry. These methods are collectively fraught with limitations in sensitivity and specificity. Fortunately, recent advances in flow cytometry, polymerase chain reaction, high throughput sequencing, and other molecular techniques have shown promise in improving diagnosis and treatment of CTCL. Examples of these advances include T cell receptor clonotyping via sequencing to detect CTCL earlier in the disease course and single-cell RNA sequencing to identify gene expression patterns that commonly drive CTCL pathogenesis. Experience with these techniques has afforded novel insights which may translate into enhanced diagnostic and therapeutic approaches for CTCL.

HLA-DR Helps to Differentiate Erythrodermic Cutaneous T-cell Lymphoma from Erythrodermic Inflammatory Dermatoses in Flow Cytometry

Differential diagnosis of erythroderma is challenging in dermatology, especially in differentiating erythrodermic cutaneous T-cell lymphoma from erythrodermic inflammatory dermatoses. This study retrospectively reviewed the peripheral blood flow cytometric results of 73 patients diagnosed with erythroderma at Peking University First Hospital from 2014 to 2019. The flow cytometry antibody panel included white blood cell markers, T-cell markers, B-cell markers, T-cell activation markers, and T helper cell differentiation markers. Features of the cell surface antigens were compared between 34 patients with erythrodermic cutaneous T-cell lymphoma and 39 patients with erythrodermic inflammatory dermatoses. The percentage of HLA-DR+/CD4+T cells was the most pronounced marker to distinguish erythrodermic cutaneous T-cell lymphoma from erythrodermic inflammatory dermatoses, with a threshold of 20.85% (sensitivity 96.77%, specificity 70.37%, p = 0.000, area under the curve (AUC) 0.882), suggesting its potential capability in the differential diagnosis of erythrodermic cutaneous T-cell lymphoma from erythrodermic inflammatory dermatoses. Moreover, in contrast to erythrodermic inflammatory dermatoses, the percentage of Th17 cells was significantly downregulated in erythrodermic cutaneous T-cell lymphoma (p = 0.001), demonstrating a dysregulated immune environment in erythrodermic cutaneous T-cell lymphoma.

The Value of Immunohistochemical Expression of TOX, ICOS, and GATA-3 in the Diagnosis of Mycosis Fungoides

BACKGROUND

Mycosis fungoides (MF) is considered the commonest type of cutaneous T-cell lymphoma representing about 50% of all primary cutaneous lymphomas. Differentiation between MF and another inflammatory dermatitis (BIDs) is important to ensure proper management.

AIM

We aimed to evaluate the immunohistochemical expression of T OX, ICOS, and GATA binding protein 3 (GATA-3) in early stages MF (stage IA and IB) to establish their diagnostic value and to guide the use of inhibitors in the treatment of cutaneous T-cell lymphomas.

MATERIALS AND METHODS

A retrospective study of 75 skin paraffin blocks (punch biopsy) 40 cases of MF and 35 cases of eczematous dermatitis as a group representing other inflammatory dermatitis were retrieved from archives of the pathology department of our University, during the period from October 2017 to May 2021.

RESULTS

About 98% and 90% of patients in the MF group had positive T OX and ICOS, while 70% of them had positive GATA-3. High expression of T OX, ICOS, and GATA-3 was associated with higher stages.

CONCLUSIONS

T OX is considered a diagnostic marker for early MF. The importance of identifying novel markers in MF expressed by immunohistochemistry, such as ICOS, has been established. According to our results, GATA-3 could be used as an accessory marker in the diagnosis of MF when combined with T OX and ICOS in a panel.

[Translated article] Primary Cutaneous Lymphoma Registry of the Spanish Academy of Dermatology and Venereology (AEDV): Data for the First 5 Years

BACKGROUND AND OBJECTIVE

Primary cutaneous lymphomas (PCL) are uncommon. Observations based on the first year of data from the Spanish Registry of Primary Cutaneous Lymphomas (RELCP, in its Spanish abbreviation) of the Spanish Academy of Dermatology and Venereology (AEDV) were published in February 2018. This report covers RELCP data for the first 5 years.

PATIENTS AND METHODS

RELCP data were collected prospectively and included diagnosis, treatments, tests, and the current status of patients. We compiled descriptive statistics of the data registered during the first 5 years.

RESULTS

Information on 2020 patients treated at 33 Spanish hospitals had been included in the RELCP by December 2021. Fifty-nine percent of the patients were men; the mean age was 62.2 years. The lymphomas were grouped into 4 large diagnostic categories: mycosis fungoides/Sézary syndrome, 1112 patients (55%); primary B-cell cutaneous lymphoma, 547 patients (27.1%); primary CD30⁺ lymphoproliferative disorders, 222 patients (11%), and other T-cell lymphomas, 116 patients (5.8%). Nearly 75% of the tumors were registered in stage I. After treatment, 43.5% achieved complete remission and 27% were stable at the time of writing. Treatments prescribed were topical corticosteroids (1369 [67.8%]), phototherapy (890 patients [44.1%]), surgery (412 patients [20.4%]), and radiotherapy (384 patients [19%]).

CONCLUSION

The characteristics of cutaneous lymphomas in Spain are similar to those reported for other series. The large size of the RELCP registry at 5 years has allowed us to give more precise descriptive statistics than in the first year. This registry facilitates the clinical research of the AEDV's lymphoma interest group, which has already published articles based on the RELCP data.

Characteristics and Outcomes for Hospitalized Patients With Cutaneous T-Cell Lymphoma

Importance

Cutaneous T-cell lymphoma (CTCL) is a group of rare, complex cutaneous malignant neoplasms associated with significant disease burden on patients and the health care system. Currently, the population of patients with CTCL admitted to the hospital remains largely uncharacterized and poorly understood.

Objective

To characterize the clinical characteristics, course of hospitalization, and mortality outcomes of an inpatient CTCL cohort.

Design, Setting, and Participants

This multicenter retrospective cohort study reviewed medical records for adult patients (age ≥18 years) with a CTCL diagnosis per National Comprehensive Cancer Network guidelines admitted for inpatient hospitalization at 5 US academic medical centers with inpatient dermatology consult services and CTCL clinics between August 2016 and August 2020.

Main Outcomes and Measures

Patient demographics, clinical history and findings, hospitalization courses, and mortality outcomes.

Results

A total of 79 hospitalized patients with CTCL were identified, including 52 (70.3%) men and 22 (29.7%) women, with a median (IQR) age at hospitalization of 62.9 (27-92) years. The majority of admitted patients with CTCL were White (65 patients [82.3%]), had disease classified as mycosis fungoides (48 patients [61.5%]), and had advanced-stage disease (≥IIB, 70 patients [89.7%]). Most hospitalizations were complicated by infection (45 patients [57.0%]) and required intravenous antibiotic therapy (45 patients [57.0%]). In-hospital mortality occurred in 6 patients (7.6%) and was associated with higher body mass index (36.5 vs 25.3), history of thromboembolic disease (50.0% vs 12.3%), and diagnosis of sepsis on admission (66.7% vs 20.5%). At 1-year postdischarge, 36 patients (49.3%) patients had died, and mortality was associated with history of solid organ cancers (27.8% vs 10.8%), wound care as the reason for dermatology consultation (58.3% vs 24.3%), and presence of large cell transformation (58.3% vs 22.9%).

Conclusions and Relevance

The findings of this cohort study improve the understanding of hospitalized patients with CTCL and lend valuable insight into identifying factors associated with both in-hospital and long-term mortality outcomes. This refined understanding of the inpatient CTCL population provides a foundation for larger, more robust studies to identify causal risk factors associated with mortality, development of prognostic scoring systems to estimate the probability of hospital mortality. Overall, the findings may prompt physicians caring for patients with CTCL to implement preventive strategies to diminish hospitalization and improve clinical management across this unique disease spectrum.

Disseminated T-cell lymphoma with non-epitheliotropic cutaneous involvement in a cat with erythematous patches and regenerative anemia

A 14-y-old, castrated male, diabetic, domestic longhaired cat was presented for investigation of anemia. General examination revealed widespread cutaneous erythematous macules and patches. Hematology and bone marrow aspiration revealed severe regenerative anemia and marked erythroid hyperplasia, respectively. Low numbers of intermediate-to-large, atypical lymphocytes were observed in the blood smear and bone marrow aspirates. Various imaging modalities demonstrated a diffuse pulmonary bronchial pattern, multifocal mural thickening of the urinary bladder, splenomegaly, and mild tri-cavitary effusion. Skin biopsies and cytologic examination of the pleural effusion demonstrated round-cell neoplasia consistent with lymphoma. Autopsy confirmed disseminated T-cell lymphoma, mostly affecting the urinary bladder, stomach, lymph nodes, and interscapular subcutis and muscles. Angiocentrism and nerve infiltration were present. The cutaneous erythematous patches, characterized by perivascular neoplastic lymphocytic infiltrates and angiodestruction, were a manifestation of the disseminated lymphoma in this cat, similar to the lesions reported in humans affected by angioimmunoblastic T-cell lymphoma.

[Unilocular cutaneous lymphoma : the hand and the blade]

Mycosis fungoides (MF) is the most frequent form of cutaneous lymphomas. MF is known as the great mimicker. The tumour d'emblee form is an exceptional presentation, for which there is no precise treatment guidance. A 45-year old man presented with tumoral MF on the dorsal side of his right hand with an extension to the forefinger. After the histological, immunohistological and the TCR monoclonality proof of MF, different topical and systemic treatments have been administered. As none of these treatments provided satisfying clinical responses, a surgical excision was finally proposed, with a very good clinical outcome and no recurrence observed after 2 months. Although exceptional in the event of an MF in general, localized tumoral forms of MF could readily benefit from a surgical excision.

Primary cutaneous gamma-delta T-cell lymphoma masquerading as leukemia cutis in a patient recently diagnosed with small lymphocytic lymphoma: Clues to the diagnosis

A 54-year-old man recently diagnosed with small lymphocytic lymphoma (SLL) had waxing and waning, indurated, erythematous plaques on his legs, with leukopenia and anemia disproportionate to the SLL burden in his marrow and pelvic lymph nodes. Punch biopsy of a plaque performed to evaluate for leukemia cutis revealed a lymphocytic lobular-panniculitis-like infiltrate resembling lupus panniculitis, but a preponderance of CD8+/Ki-67+ T-cells surrounding adipocytes raised concern for subcutaneous panniculitis-like T-cell lymphoma (SPTCL). Additional immunohistochemistry (IHC) studies showed that the adipotropic T-cells expressed TCR-gamma, supporting the rare, unexpected diagnosis of Primary cutaneous gamma-delta T-cell lymphoma (PCGDTCL). The patient subsequently met diagnostic criteria for hemophagocytic lymphohistiocytosis (HLH). PCGDTCL is an aggressive, HLH-associated lymphoma requiring different management than SPTCL and SLL. This case illustrates how PCGDTCL can co-exist with B-cell lymphoma and resemble panniculitis on biopsies. PCGDTCL and SPTCL should enter the differential diagnosis whenever patients present with the constellation of lobular panniculitis and unexplained cytopenias. In the present case, close clinicopathologic correlation and judicious use of IHC on a small sample allowed for a prompt diagnosis.

Surgical, Dermatological and Morphopathological Considerations in the Diagnosis and Treatment of Cutaneous Lymphoproliferative Tumors, Primary CD4+

Primary cutaneous lymphomas are a heterogeneous group of T-cell (CTCL) and B-cell lymphomas (CBCL) developing in the skin and without signs of extracutaneous disease at the time of diagnosis. The term “primary small/medium CD4+ T-cell lymphoma” was changed to “primary small/medium cutaneous CD4+ lymphoproliferative disorder” due to its indolent clinical behavior and uncertain malignant potential. This paper presents a rare case of primary cutaneous lymphoma with small to medium CD4+ T-cells. A 37-year-old patient presented with a tumor in the frontal region that had occurred approximately 8–9 months earlier. The tumor had a diameter of about 8–9 mm, well demarcated macroscopically, it was round in shape, about 6–7 mm high, pink in color, firm in consistency and painless during palpation. Surgical excision of the tumor was performed with a margin of safety of 8 mm and deep to the level of the frontal muscle fascia. The histopathological examination supported the diagnosis of cutaneous lymphoproliferation with a nodular disposition in the reticular dermis and extension around the follicular epithelia and sweat glands, composed mainly of dispersed medium-large lymphocytes. Additional immunohistochemical examination was requested. Immunohistochemical examination confirmed the diagnosis of “primary cutaneous CD4+ small/medium T-cell lymphoproliferative disorder.” Patient monitoring was carried out through clinical dermatological controls at 3, 6, and 12 months. After one year, a cranio-cerebral MRI was performed. For the following 5 years, an annual dermatological examination accompanied by cranio-cerebral MRI, blood count, and pulmonary X-ray were recommended. Similarly to all solitary skin lesions, the prognosis is excellent in this case, the only treatment being surgical excision.

Primary cutaneous lymphoma: recommendations for clinical trial design and staging update from the ISCL, USCLC, and EORTC

The number of patients with primary cutaneous lymphoma (PCL) relative to other non-Hodgkin lymphomas (NHLs) is small and the number of subtypes large. Although clinical trial guidelines have been published for mycosis fungoides/Sézary syndrome, the most common type of PCL, none exist for the other PCLs. In addition, staging of the PCLs has been evolving based on new data on potential prognostic factors, diagnosis, and assessment methods of both skin and extracutaneous disease and a desire to align the latter with the Lugano guidelines for all NHLs. The International Society for Cutaneous Lymphomas (ISCL), the United States Cutaneous LymphomaConsortium (USCLC), and the Cutaneous Lymphoma Task Force of the European Organization for the Research and Treatment of Cancer (EORTC) now propose updated staging and guidelines for the study design, assessment, endpoints, and response criteria in clinical trials for all the PCLs in alignment with that of the Lugano guidelines. These recommendations provide standardized methodology that should facilitate planning and regulatory approval of new treatments for these lymphomas worldwide, encourage cooperative investigator-initiated trials, and help to assess the comparative efficacy of therapeutic agents tested across sites and studies.

The PROCLIPI international registry, an important tool to evaluate the prognosis of cutaneous T cell lymphomas

PROCLIPI is the PROgnostic Cutaneous Lymphoma International Prognostic Index Study with the main aim to produce a prognostic index in mycosis fungoides (MF) and Sezary syndrome (SS). The study prospectively collects clinical, haematological, pathological, imaging, treatment with responses, quality of life and survival data using careful predefined datasets. Patients are subject to a central review to confirm diagnosis. PROCLIPI opened in 2015 and recruitment has been strong with to date 1916 patients recruited from 52 Centres from 19 countries across 6 continents.

Survival and Prognostic Factors in Patients with Aggressive Cutaneous T-cell Lymphomas

Aggressive primary cutaneous T-cell lymphomas include advanced-stage mycosis fungoides (stage ≥ IIB mycosis fungoides), Sézary syndrome, gamma/delta cutaneous lymphoma, nasal type lymphoma, aggressive epidermotropic CD8+ T-cell lymphoma and some cutaneous lymphomas not otherwise specified. To evaluate their long-term prognosis, we conducted a retrospective cohort study of 85 patients diagnosed between 2005 and 2020 with advanced-stage mycosis fungoides (n = 48), Sézary syndrome (n = 28) or aggressive non-mycosis fungoides/Sézary syndrome subtypes (n = 9). The median survival times in these 3 groups were 118.7, 45.7 and 11.2 months, respectively, and the 5-year survival rates were 55.3%, 27.8% and 33.3%, respectively. Multivariate analyses in patients with mycosis fungoides/Sézary syndrome identified age ≥ 70 years, Eastern Cooperative Oncology Group Performance Status ≥ 2, and the high-risk group according to the Cutaneous Lymphoma International Consortium prognostic model, as adverse prognostic factors. Seven patients in this mycosis fungoides/Sézary syndrome group were in complete long-term remission after treatment with bexarotene, including 4 patients living without any treatment for 16–101 months.

T cells in the skin: lymphoma and inflammatory skin disease

T cells are established contributors to the pathogenesis of atopic dermatitis (AD) and psoriasis, yet whether they are the key drivers or simply unwitting participants remains incompletely understood. Conversely, malignant T cells are the undisputed culprits of cutaneous T cell lymphoma (CTCL), a group of diseases that share key clinical, histopathological and molecular features with inflammatory skin disease (ISD). Here, we compare the pathogenesis of ISD and CTCL and discuss the resulting insights. Recurrent, skin-limited disease implicates skin-resident T cells (T_RM) in both ISD and CTCL. In CTCL, malignant T cells recruit benign T cells into inflammatory skin lesions, a disease-amplifying function also proposed for pathogenic T cells in ISD. Mechanistically, cytokines produced by malignant T cells in CTCL and by pathogenic T cells in ISD, respectively, are likely both necessary and sufficient to drive skin inflammation and pruritus, which in turn promotes skin barrier dysfunction and dysbiosis. Therapies for ISD target T cell effector functions but do not address the chronicity of disease while treatments for CTCL target malignant T cells but not primarily the symptoms of the disease. By integrating our understanding of ISD and CTCL, important insights into pathogenesis and therapy can be made which may improve the lives of sufferers of both disease groups.

Bexarotene-induced central hypothyroidism assessed by TRH stimulation test in cutaneous T-cell lymphoma patients

Bexarotene-induced central hypothyroidism (CH), for which levothyroxine (LT4) replacement is recommended, has been shown to be caused by pituitary but not hypothalamic disorder experimentally, though the underlying mechanism in humans remains unclear. Here, the pathophysiology of bexarotene-induced CH was examined using a TRH stimulation test in cutaneous T-cell lymphoma (CTCL) patients. In this retrospective longitudinal observational study, serum TSH and free T4 (F-T4) levels were measured in 10 euthyroid patients with CTCL during 24 weeks of bexarotene treatment. TRH stimulation testing was performed following CH diagnosis, with LT4 replacement dosage adjusted to maintain F-T4 at the pre-treatment level. After one week of bexarotene administration, all 10 patients developed CH, based on combined findings of low or low-normal F-T4 with low or normal TSH levels. TSH peak response after a stimulation test at one week was reached at 30 minutes. However, that was <4 μIU/mL in all patients, indicating a blunted though not exaggerated and delayed TSH response. In eight who continued bexarotene for 24 weeks, median LT4 replacement dosage was 125 (range, 75-150) μg/day. TSH level at 30 as well as 15, 60, 90, and 120 minutes after TRH stimulation was significantly correlated with LT4 replacement dosage (ρ = -0.913, p = 0.002), whereas TSH and F-T4 basal levels at one week were not. These results suggest that pituitary hypothyroidism is responsible for bexarotene-induced CH, while TSH levels after TRH stimulation precisely reflect residual pituitary-thyroid function in patients receiving bexarotene.

Determining the immune environment of cutaneous T-cell lymphoma lesions through the assessment of lesional blood drops

Detailed analysis of the cells that infiltrate lesional skin cannot be performed in skin biopsy specimens using immunohistochemistry or cell separation techniques because enzyme treatments applied during the isolation step can destroy small amounts of protein and minor cell populations in the biopsy specimen. Here, we describe a method for isolating T cells from drops of whole blood obtained from lesions during skin biopsy in patients with cutaneous T-cell lymphoma. Lesional blood is assumed to contain lesional resident cells, cells from capillary vessels, and blood overflowing from capillary vessels into the lesion area. The lesional blood showed substantial increases in distinct cell populations, chemokines, and the expression of various genes. The proportion of CD8+CD45RO+ T cells in the lesional blood negatively correlated with the modified severity-weighted assessment tool scores. CD4+CD45RO+ T cells in the lesional blood expressed genes associated with the development of cancer and progression of cutaneous T-cell lymphoma. In addition, CD8+CD45RO+ T cells in lesional blood had unique T-cell receptor repertoires in lesions of each stage. Assessment of lesional blood drops might provide new insight into the pathogenesis of mycosis fungoides and facilitate evaluation of the treatment efficacy for mycosis fungoides as well as other skin inflammatory diseases.

Cutaneous T-cell lymphomas: 2021 update on diagnosis, risk-stratification, and management

DISEASE OVERVIEW

Cutaneous T-cell lymphomas are a heterogenous group of T-cell neoplasms involving the skin, the majority of which may be classified as Mycosis Fungoides (MF) or Sézary Syndrome (SS).

DIAGNOSIS

The diagnosis of MF or SS requires the integration of clinical and histopathologic data.

RISK-ADAPTED THERAPY

TNMB (tumor, node, metastasis, blood) staging remains the most important prognostic factor in MF/SS and forms the basis for a "risk-adapted," multi-disciplinary approach to treatment. For patients with disease limited to the skin, expectant management or skin-directed therapies is preferred, as both disease-specific and overall survival for these patients is favorable. In contrast, patients with advanced-stage disease with significant nodal, visceral or blood involvement are generally approached with systemic therapies, including biologic-response modifiers, histone deacetylase inhibitors, or antibody-based strategies, in an escalating fashion. In highly-selected patients, allogeneic stem-cell transplantation may be considered, as this may be curative in some patients.

A Rare Case of Cutaneous Intravascular NK/T-Cell Lymphoma

BACKGROUND

Cutaneous intravascular NK/T cell lymphoma (CIVNKTC) is a rare form of extranodal non-Hodgkin's lymphoma with its unique histological and immunophenotypic characteristics.

METHODS

We report a case presenting with an over 2-month history of nodules on the extremities and trunk with intermittent fever. Skin biopsy was taken from the patient and a histopathological examination was made from the material.

RESULTS

The histopathological examination showed some expanding vessels filled with atypical lymphoid cells in the dermis and subcutaneous tissue. The tumor cells had large nuclei and one or two small nucleoli, with the expression of CD3, cytotoxic protein, and Epstein-Barr virus (EBV)-encoded messenger RNAs (EBER), and without the expression of tumor cytokeratin (CK), CD20, CD79A, CD4, and CD8. After being diagnosed as CIVNKTC and treated with a CHOP regimen 6 times, the patient died of this disease 1 year later.

CONCLUSIONS

The clinical course is dangerous and the prognosis is extremely poor.

Diagnosis and Management of Cutaneous Lymphomas Including Cutaneous T-cell Lymphoma

The cutaneous lymphomas are malignancies of T-cell and B-cell lymphocytes in which the skin is the primary organ of involvement. The cutaneous T-cell lymphomas include variants that can mimic the presentation of common skin diseases or arthropod bites. Mycosis fungoides, the most common cutaneous T-cell lymphoma, usually presents as fixed asymptomatic patches or plaques in sun-protected areas. The cutaneous B-cell lymphomas have fewer variants that often present as papules or nodules that can mimic nonmelanoma skin cancers. Some therapies for cutaneous lymphoma have unique side effects such as central hypothyroidism, hyperlipidemia, and peripheral neuropathy.

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.

Diagnostic Value of Genotypic Analysis in Primary Cutaneous Lymphomas using Standardized BIOMED-2 Polymerase Chain Reaction Protocols: Experience in Daily Clinical Practice

BIOMED-2 Concerted Action BMH4-CT98-3936 (BIOMED-2) PCR protocols are an important diagnostic tool in the evaluation of cutaneous lymphomas. The aim of this study was to assess the diagnostic value of the genotyping results obtained by these techniques in daily clinical practice. A total of 360 paraffin-embedded skin samples were retrospectively reviewed from 114 cutaneous T-cell lymphomas and 35 cutaneous B-cell lymphomas. A total of 249 biopsies from 180 patients with benign lymphoid infiltrates served as controls. T-cell receptor and immunoglobulin gene rearrangements were assessed using the BIOMED-2 method. A combined T-cell receptor gamma and beta assay approach reliably distinguished cutaneous T-cell lymphomas from benign skin T-cell infiltrates (sensitivity 89.4%; specificity 81.5%). Analysis of complete immunoglobulin heavy chain rearrangements also differentiated cutaneous B-cell lymphomas from benign B-cell infiltrates (sensitivity 85.7%; specificity 82.4%). In conclusion, the full BIOMED-2 protocol is a useful aid combined with clinical, histological and immunophenotypical findings for assessment of lymphoid clonality in skin lymphoid proliferations.

[Primary cutaneous CD4+ small to medium-sized T-cell lymphoma in an adolescent patient]

A rare finding of primary cutaneous CD4+ small to medium-sized T‑cell lymphoma (SMPTCL) in a fifteen-year-old patient is reported. This is a rare tumor entity for which there is currently no standardized treatment recommendation. At the interdisciplinary tumor board, the decision was made to resect the tumor and reconstruct the defect with a nasolabial advancement flap in a two-stage process. Follow-up examinations, currently over 3 years, have shown the patient to be free of recurrences.

Diagnosis of cutaneous T-cell lymphoma by insurance type before and after the Affordable Care Act: a national database study

The Affordable Care Act (ACT) was implemented to increase health care access and reduce the uninsured in the age group between pediatric and Medicare populations (18-64). The association of the ACA with insurance type upon diagnosis (uninsured, Medicaid, non-Medicaid) has been investigated for otolaryngologic, gynecologic, and the top five non-skin malignancies. Such studies for cutaneous malignancies are lacking. We conducted a retrospective analysis of the prospective National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) cancer database to assess the impact of the ACA on new diagnoses of cutaneous T-cell lymphoma (CTCL) by insurance type. Unlike prior studies of other malignancies, we did not observe significant differences between rate of diagnosis of CTCL by insurance type before and after full implementation of the ACA in all states, expansion states, and non-expansion states. Skin cancers do not have screening guidelines and CTCL is an uncommon malignancy, both of which may contribute to these findings. However, Medicaid-expansion states were much closer to reducing the percentage of newly diagnosed uninsured patients with CTCL than non-expansion states. As such, it may be prudent to investigate intrinsic socioeconomic barriers to care in Medicaid patients to improve their access to care to decrease the uninsured population and improve outcomes.