Paediatric-onset lymphomatoid papulosis: results of a multicentre retrospective cohort study on behalf of the EORTC Cutaneous Lymphoma Tumours Group (CLTG).

BACKGROUND: Lymphomatoid papulosis (LyP) is a rare cutaneous T-cell lymphoproliferative disorder. Comprehensive data on LyP in the paediatric population are scarce. OBJECTIVES: To characterize the epidemiological, clinical, histopathological and prognostic features of paediatric LyP. METHODS: This was a retrospective multicentre international cohort study that included 87 children and adolescents with LyP diagnosed between 1998 and 2022. Patients aged ≤ 18 years at disease onset were included. LyP diagnosis was made in each centre, based on clinicopathological correlation. RESULTS: Eighty-seven patients from 12 centres were included. Mean age at disease onset was 7.0 years (range 3 months-18 years) with a male to female ratio of 2 : 1. Mean time between the onset of the first cutaneous lesions and diagnosis was 1.3 years (range 0-14). Initial misdiagnosis concerned 26% of patients. LyP was most often misdiagnosed as pityriasis lichenoides et varioliformis acuta, insect bites or mollusca contagiosa. Erythematous papules or papulonodules were the most frequent clinical presentation. Pruritus was specifically mentioned in 21% of patients. The main histological subtype was type A in 55% of cases. When analysed, monoclonal T-cell receptor rearrangement was found in 77% of skin biopsies. The overall survival rate was 100%, with follow-up at 5 years available for 33 patients and at 15 years for 8 patients. Associated haematological malignancy (HM) occurred in 10% of cases (n = 7/73), including four patients with mycosis fungoides, one with primary cutaneous anaplastic large cell lymphoma (ALCL), one with systemic ALCL and one with acute myeloid leukaemia. If we compared incidence rates of cancer with the world population aged 0-19 years from 2001 to 2010, we estimated a significantly higher risk of associated malignancy in general, occurring before the age of 19 years (incidence rate ratio 87.49, 95% confidence interval 86.01-88.99). CONCLUSIONS: We report epidemiological data from a large international cohort of children and adolescents with LyP. Overall, the disease prognosis is good, with excellent survival rates for all patients. Owing to an increased risk of associated HM, long-term follow-up should be recommended for patients with LyP.

Lymphomatoid papulosis is a very rare skin condition caused by an abnormal increase in white blood cells (called 'lymphocytes') in the skin. The condition rarely affects children, so most of the scientific data published about this disease focuses on adults. This study involved 12 academic dermatology centres in Europe, the Middle East and North America, and gathered data from about 87 children who presented with symptoms of lymphomatoid papulosis before the age of 19 years. The aim of this study was to better describe this disease in the paediatric population and discuss its treatment options and evolution. We found that the presentation of the disease in children is roughly the same as in adults. Safe and effective treatment options exist. The disease is not life threatening, but it requires investigation by a dermatologist, both to make a careful diagnosis and to monitor it as sometimes associated cancers that originate from blood cells can occur, mostly on the skin.

Paediatric cutaneous lymphomas including rare subtypes: A 40-year experience at a tertiary referral centre.

BACKGROUND: Primary cutaneous lymphomas are neoplasms of the immune system with a distinct tropism for the skin and an absence of extracutaneous manifestations at the time of diagnosis. Studies focusing on cutaneous lymphomas in children and adolescents remain scarce and often do not encompass the rare subtypes. OBJECTIVES: To address this knowledge gap by describing the clinical, histological and molecular characteristics of a large group of paediatric patients affected by primary cutaneous lymphoma. We also provided the Paediatric Primary Cutaneous Lymphoma Atlas that illustrates the clinicopathological spectrum of observed presentations, in the hope of supporting other physicians in the diagnostic process. METHODS: Retrospective chart review of paediatric patients diagnosed with primary cutaneous lymphomas between 1980 and 2022 at the Paediatric Dermatology Unit of Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan. RESULTS: A total of 101 patients (58 males, 43 females) met the inclusion criteria. The most common subtypes were lymphomatoid papulosis (n = 48) and mycosis fungoides (n = 31). These were followed by primary cutaneous CD4+ small/medium T-cell lymphoproliferative disorders (n = 7), primary cutaneous anaplastic large-cell lymphomas (n = 5), primary cutaneous marginal zone B-cell lymphomas (n = 3), primary cutaneous follicle centre lymphomas (n = 2), subcutaneous panniculitis-like T-cell lymphomas (n = 2), primary cutaneous peripheral T-cell lymphoma not otherwise specified (n = 1), primary cutaneous precursor B-lymphoblastic lymphoma (n = 1) and Sézary syndrome (n = 1). Clinical follow-up data covering a median of 70.8 months (range 1-324) were available for 74 patients, of whom three died due to cutaneous lymphoma. CONCLUSIONS: Our findings shed light on the peculiar aspects and long-term outcomes of paediatric cutaneous lymphomas, particularly emphasizing their distinctive features in comparison to their adult counterparts and exploring the less common subtypes. Further larger-scale studies are warranted to better characterize these entities and to achieve a more rapid and accurate diagnosis.

Disseminated superficial actinic porokeratosis following hydroxyurea treatment: A case report.

Porokeratosis encompass a group of acquired and familial, preneoplastic, keratinization disorders, clinically characterized by atrophic macules or patches with a peripheral keratotic rim, the cornoid lamella. Genetic background is recognized as crucial in its pathophysiology, while immunosuppression and ultraviolet radiation represent triggering factors. We report the case of a woman who developed disseminate superficial actinic porokeratosis following the intake of hydroxyurea for a polycythaemia vera. Clinical, dermoscopic and histopathology data are showed, and the role of drug as a second-hit mutation trigger is discussed.

CCR4 in cutaneous T-cell lymphoma: Therapeutic targeting of a pathogenic driver.

New treatments are needed for patients with cutaneous T-cell lymphoma (CTCL), particularly for advanced mycosis fungoides (MF) and Sezary syndrome (SS). The immunopathology of MF and SS is complex, but recent advances in tumor microenvironment understanding have identified CCR4 as a promising therapeutic target. CCR4 is widely expressed on malignant T cells and Tregs in the skin and peripheral blood of patients with MF and SS. The interaction of CCR4 with its dominant ligands CCL17 and CCL22 plays a critical role in the development and progression of CTCL, facilitating the movement into, and accumulation of, CCR4-expressing T cells in the skin, and recruiting CCR4-expressing Tregs into the tumor microenvironment. Expression of CCR4 is upregulated at all stages of MF and in SS, increasing with advancing disease. Several CCR4-targeted therapies are being evaluated, including "chemotoxins" targeting CCR4 via CCL17, CCR4-directed chimeric antigen receptor-modified T-cell therapies, small-molecule CCR4 antagonists, and anti-CCR4 monoclonal antibodies. Only one is currently approved: mogamulizumab, a defucosylated, fully humanized, anti-CCR4, monoclonal antibody for the treatment of relapsed/refractory MF and SS. Clinical trial da1ta confirm that mogamulizumab is an effective and well-tolerated treatment for relapsed/refractory MF or SS, demonstrating the clinical value of targeting CCR4.

Italian expert-based recommendations on the use of photo(chemo)therapy in the management of mycosis fungoides: Results of an e-Delphi consensus.

BACKGROUND: Phototherapy is a mainstay for the treatment of MF. However, there is scarce evidence for its use, mostly due to the lack of a unified schedule. AIMS: The primary aim of this study was to establish the first structured, expert-based consensus regarding the indications and technical schedules of NB-UVB and PUVA for MF. The secondary aim was to determine the consensus level for each specific item. MATERIALS & METHODS: E-delphi study. Item-specific expert consensus was defined as the number of "Totally Agree" results to ≥80% of the panelists. Cronbach alpha index ≥0.7 was used as a measure of homogeneity in the responses among questions related to the same topic. RESULTS: Overall, there was a high homogeneity among responders (0.78). On specific topics, the highest grade was observed for technical items (0.8) followed by indications for early (0.73) and advanced stages (0.7). CONCLUSIONS: Items related to the most canonical indications of phototherapy and to treatment schedules showed the highest agreements rates. There is consensus about the use of standardized treatment schedules for the induction and consolidation phases for NB-UVB and PUVA in MF.

CD30 expression in a case of intravascular large B-cell lymphoma, cutaneous variant.

Intravascular large B-cell lymphoma (IVLBCL) is one of the rarest B-cell non-Hodgkin lymphomas (NHL), with an aggressive clinical behavior and a poor prognosis; in fact, its treatment is still an unmet clinical need, with a 3-year overall survival (OS) rate of 60% to 81%, and a central nervous system relapse rate of 25%. It usually presents as a widespread disease at diagnosis, with multi-organ involvement. Previously considered as a diffuse large B-cell lymphoma variant, it now represents a different extranodal large B-cell lymphoma entity in the last WHO Classification of tumors of hematopoietic and lymphoid tissues. We hereby describe the case of an 84-year-old Italian woman with an IVLBCL, cutaneous variant, who suffered from early relapse after R-COMP chemotherapy regimen, and was therefore treated with a palliative metronomic chemotherapy. Interestingly, neoplastic cells showed CD30 expression at relapse. CD30 positivity has never been reported in this disease so far, and its expression is known to be involved in NF-kB activation. CD30 expression may be further studied as for prognostic and therapeutic significance; in fact, new therapeutic strategies, such as antibody-drug conjugate targeting CD30, are now available.

Array-based CGH of primary cutaneous CD8+ aggressive EPIDERMO-tropic cytotoxic T-cell lymphoma.

Primary cutaneous CD8+ aggressive epidermotropic cytotoxic T-cell lymphoma (pcAECyTCL) is a rare provisionally categorized cutaneous lymphoma characterized by an aggressive course. Its pathogenesis and molecular mechanisms are still unknown, and only two individual cases have so far been molecularly characterized. The aim of this study was to define the pattern of numerical chromosomal alterations in tumor samples taken from 20 patients with pcAECyTCL at the time of diagnosis by means of array-comparative genomic hybridization (a-CGH). a-CGH detected numerous genomic aberrations in all the patients and, putting these together as a whole, they affected all the chromosomes. However, no specific profile of recurrent copy number alterations (CNAs) was found. Most of the gains involved regions previously described in other aggressive cutaneous lymphomas such as 7q, 8q24.3, and 17q, whereas the most significant CNA was the loss of 9p21.3 (CDKN2A-CDKN2B), which has already been found in a variety of malignant tumors and is associated with aggressive cutaneous T-cell lymphomas. In brief, CGH analysis revealed a large number of CNAs with only few recurring regions that probably do not represent driving events. The genomic instability found in this aggressive variant of cutaneous lymphoma may therefore be a secondary event but, at the time of the diagnosis of pcAECyTCL, the genomic integrity of tumor cells is already compromised.

Primary cutaneous acral CD8 positive T-cell lymphoma with extra-cutaneous involvement: A long-standing case with an unexpected progression.

Primary cutaneous acral CD8+ T-cell lymphoma (acral CD8+ TCL) is a new provisional entity characterized by acral skin lesions and an indolent course. We describe an extraordinary case characterized by relapsed nodules with CD8+ cytotoxic infiltrates on the left ear. After 35 years, the skin lesions spread to other acral sites, and a mass with the same histological features as the other skin lesions appeared on the nose. Multiple courses of chemotherapy led to stable disease. Histological examinations carried out at different times showed the gradual transformation of the neoplastic cells, with an increased proliferation index. Genomic analysis revealed losses in the regions harboring the genes involved in cell cycle control. This is the first case of an acral CD8+ TCL with a very long history of indolent nodular lesions progressing to extra-cutaneous sites.

Clinicopathological and molecular study of primary cutaneous CD4+ small/medium-sized pleomorphic T-cell lymphoma.

BACKGROUND: Primary cutaneous CD4+ small-/medium-sized pleomorphic T-cell lymphoma (CD4+ PCSM-TCL) is a rare lymphoproliferative disorder with a favorable prognosis. Distinguishing it from other cutaneous lymphomas is often a challenge. METHODS: We retrospectively collected CD4+PCSM-TCL cases from two centers (MD Anderson Cancer Center, USA and University of Milan, Italy) and evaluated their clinicopathological features. Array-comparative genomic hybridization (aCGH) analysis was performed on 11 cases. RESULTS: A total of 62 patients were identified. Single lesions were the most common clinical presentations (79%). Five patients (8%) showed multiple MF-like plaques. All patients' disease had an indolent course. The infiltrate was nodular and diffuse, multinodular or superficial but in all cases, it was characterized by small/medium pleomorphic CD4+/CD279(PD1+) lymphocytes grouped in clusters and 'pseudorosettes' around B-cells. aCGH analysis showed no significant genomic abnormalities. Single lesions were mainly treated with surgical excision (91%) and/or radiotherapy (95%) with low rate of relapse (12%). For multiple lesions, topical steroids, nitrogen mustard and phototherapy were mainly used but the rate of relapse was high (69%). CONCLUSIONS: CD4+PCSM-TCL is characterized by heterogeneous clinical presentations. The arrangement of atypical cells in clusters or pseudorosettes is a useful criterion for diagnosis. The absence of significant genomic alterations is in agreement with its indolent behavior.

Sézary Syndrome in a 17-Year-Old Boy: Clinicopathologic Features and Genomic Profile.

We describe the case of a 17-year-old Hispanic boy who had had erythroderma and diffuse lymphadenopathy for approximately 6 months. A diagnosis of Sézary syndrome was made on the basis of the histologic features of the skin; the presence of the same T-cell clone on the skin, blood, and bone marrow; and the high CD4(+) lymphocyte count with an aberrant phenotype in peripheral blood; bone marrow involvement was also present. The patient was treated with systemic gemcitabine and achieved partial remission.

Primary cutaneous, epidermotropic mycosis fungoides-like presentation: critical appraisal and description of two novel cases, broadening the spectrum of ALK+ T-cell lymphoma.

Leading from a two-case series, including two patients receiving a diagnosis of epidermotropic T-cell lymphoma, featuring a mycosis fungoides (MF)-like clinical pattern and ALK expression and molecular alteration, we performed a critical appraisal of ALK+ primary cutaneous T-cell lymphomas (pcTCL). Considering our patients and the literature, 32 cases were retrieved, 7 of which featured an MF-like clinical picture over a 4-to-20-year period. MF-like cases show distinctive histology, comprising a predominantly epidermotropic infiltration of small-to-large, atypical-to-pleomorphic, with few anaplastic cells, negligible-to-intense CD30-expression, and a CD4+/cytotoxic granule+ phenotype. These features should prompt a search for ALK expression captured by the ALK D5F3 clone. Bona fide ALK+ pcTCL is very rare, and existent data suggest the presence of a broader pattern of disease, including instances mimicking MF and/or primary cutaneous CD8+ aggressive epidermotropic cytotoxic T-cell lymphoma. The major challenges in dealing with this subset include prodromal phases, misinterpreted as inflammatory dermatosis or parapsoriasis/early phase MF both clinically and histologically, while recognition of its ALK-driven biology is hampered both by the unusual clinic-pathologic pattern of the disease, which stands apart from the classical (i.e., nodal) picture of ALK+ anaplastic large cell lymphoma and by the low sensitivity of ALK1 clone. Data on its optimal management are far from being conclusive: An MF-like approach is currently chosen, but depending on CD30 and, most notably, ALK expression, a targeted therapy could be envisaged in advanced stages, as clinical response to ALK inhibition was documented in one patient.

Whole-exome sequencing is feasible on a fresh-frozen skin sample of intravascular large B cell lymphoma.

Intravascular large B-cell lymphoma (IVLBCL) is a rare aggressive extranodal non-Hodgkin lymphoma. The predominant, if not exclusive, growth of neoplastic cells within the lumina of small-sized vessels represents the hallmark of the disease. Diagnosis is challenging due to the absence of marked lymphadenopathy, the highly heterogeneous clinical presentation, and the rarity of the condition. Clinical presentation is characterized by variable combinations of nonspecific signs and symptoms (such as fever and weight loss), organ-specific focal manifestations due to altered perfusion, and hemophagocytic syndrome. The rarity of this entity and the paucity of neoplastic cells in biopsy samples hamper the study of recurrent molecular abnormalities. The purpose of this study was to explore the feasibility of a different approach to recover a sufficient amount of DNA of acceptable quality to perform next-generation sequencing studies. Here, we report the findings of whole-exome next-generation sequencing performed on a fresh-frozen cutaneous sample of IVLBCL, paired with the patient saliva used as germline DNA. To increase the cancer cell fraction, only the subcutaneous tissue was selected. With this approach, we obtained high-quality DNA and were able to identify oncogenic mutations specific for this entity and recapitulating its post-germinal center origin, even if the tumor fraction was low. Molecular studies performed on fresh-frozen cutaneous sample are feasible in IVLBCL, especially when analysis is restricted to the subcutaneous tissue. Wide adoption of this reproducible and cost-effective approach may foster further studies, which may be of help in supporting diagnosis, providing pathogenetic insights, and guiding treatment decisions.

Vitiligo: Unmet Need, Management and Treatment Guidelines.

Vitiligo is a chronic depigmenting disorder characterized by characteristic, non-scaly, chalky-white skin macules and patches, due to the loss of skin pigment. Its exact pathogenesis is still not fully understood but it seems to be an autoimmune disease where the combination of genetic, environmental, and immune factors contributes to the destruction of melanocytes in the epidermis. Vitiligo is classified into different types based on its clinical characteristics and distribution patterns. The two main forms of vitiligo are non-segmental vitiligo (NSV) and segmental vitiligo (SV). NSV is the predominant form, characterized by symmetrical skin patches, that tend to evolve over time. In contrast, SV has unilateral or band-shaped lesions that progress rapidly but often stabilize early. Herein, current unmet needs in terms of psychosocial consequences and relative lack of valid therapeutic approaches are critically analyzed and put in perspective in the Italian prescribing scenario. Finally, available management guidelines are illustrated and briefly compared, to provide context for upcoming treatment options.

Effectiveness and tolerability of chlormethine gel for the management of mycosis fungoides: a multicenter real-life evaluation.

Background: Topical chlormethine (CL) is recommended as a first-line treatment for early-stage mycosis fungoides (MF) and in 2017, the European Medicines Agency approved the CL gel formulation to treat adult patients. More recently, to increase patient compliance and adherence, clinicians have developed flexible protocols that allow the concomitant use of CL gel with topical corticosteroids in daily practice regimens. Therefore, sharing real-life data on CL gel use and side effects management may help improve the use of this agent. Objectives: To expand knowledge about the actual use of CL gel in patients with MF, the present study assessed the improvement of MF skin lesions after CL gel treatment and provided information on the management of cutaneous adverse events (AEs) in a real-life setting. Methods: This was an Italian retrospective study conducted among six dermatology referral centers. Patients ≥18 years affected by MF and in treatment with CL gel (160 µ/g), alone or in combination according to routine clinical practice, between December 2019 and December 2021 were considered. The study's primary aim was to evaluate the effectiveness of CL gel in terms of overall response rate (ORR) after 3 months of treatment. Results: A total of 79 patients (61% male) with different stages of MF (84% early stage) were included. CL gel was prescribed mainly in association with topical corticosteroids (66% of patients). ORR after 3 months of treatment was 42%, with no differences between early- and advanced-stage MF. Response rates improved over time up to 97% after 18 months of treatment. Overall, 66 AEs were reported in 67% of patients; most were hyperpigmentation (45%) and irritant contact dermatitis (37%). Six AEs led to treatment discontinuation, and five out of six (83%) patients who reported these events resumed treatment after interruption. No AEs were classified as severe. Conclusions: Our observations support the use of CL gel in patients with early- and advanced-stage MF, making it a valuable treatment option.

Interleukin-17 vs. Interleukin-23 Inhibitors in Pustular and Erythrodermic Psoriasis: A Retrospective, Multicentre Cohort Study.

Pustular and erythrodermic psoriasis are rare and difficult-to-treat conditions. It has recently been shown that interleukin (IL)-17 inhibitors can be very effective among patients with these forms of psoriasis; however, the potential of IL-23 inhibitors is largely unknown. The aim of this multicentre, retrospective study was to compare the safety, effectiveness, and drug survival of IL-17 and IL-23 inhibitors among patients affected by these rare forms of psoriasis. The study involved 27 patients with erythrodermic psoriasis and 59 with pustular psoriasis (36 with generalised pustular psoriasis and 23 with palmoplantar pustular psoriasis) treated with an IL-17 or IL-23 inhibitor. The effectiveness of the two drug classes was assessed using the disease-specific Psoriasis Area Severity Index (PASI) and the Investigator Global Assessment, which were evaluated at different time points. There was a consistent trend towards a higher rate of PASI 100 responses in the patients treated with IL-17 inhibitors compared with those treated with IL-23 inhibitors, and the other efficacy outcomes showed a similar trend. There was no significant between-drug class difference in efficacy at any of the time points in the erythrodermic psoriasis cohort, whereas PASI 90 and PASI 100 response rates were significantly higher among the pustular psoriasis patients receiving IL-17 inhibitors at week 12 (IL-23 19% vs. IL-17 54% and IL-23 6% vs. IL-17 40%, respectively) and the percentage of responders to IL-17 inhibition was significantly higher at week 24 (IL-23 25% vs. IL-17 74%). In conclusion, it is therefore reasonable to assume that IL-17 and IL-23 inhibitors are both effective when treating pustular and erythrodermic psoriasis.

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.