Pediatric mycosis fungoides - characteristics, management, and outcomes with particular focus on the folliculotropic variant

Histopathological Markers for Target Therapies in Primary Cutaneous Lymphomas

In recent years, targeted (biological) therapies have become available also for primary cutaneous T-cell lymphomas (PCTCLs) including anti-CD30 (brentuximab vedotin) in mycosis fungoides, primary cutaneous anaplastic large T-cell lymphoma, lymphomatoid papulosis; anti-CCR4 (mogamulizumab) in Sezary syndrome; anti-CD123 (tagraxofusp) in blastic plasmocytoid cell neoplasm. Moreover, anti-PD1 (nivolumab), anti-PDL1 (pembrolizumab, atezolizumab), anti-CD52 (alemtuzumab), anti-KIR3DL2-CD158k (lacutamab), and anti-CD70 (cusatuzumab) have been tested or are under investigations in phase II trials. The expression of these epitopes on neoplastic cells in skin biopsies or blood samples plays a central role in the management of PCTCL patients. This narrative review aims to provide readers with an update on the latest advances in the newest therapeutic options for PCTCLs.

Real-World Clinical Characteristics, Management, and Outcomes of 44 Paediatric Patients with Hypopigmented Mycosis Fungoides

Hypopigmented mycosis fungoides is a rare form of mycosis fungoides that is characterized by achromic lesions, early onset of disease, a predilection for darker skinned populations, and a predominance of CD8+ T cells. Due to the rarity and heterogeneous presentation of hypopigmented mycosis fungoides, there are no criteria that clearly define the clinical characteristics and treatment regimens for this condition. This retrospective study of 44 paediatric patients with hypopigmented mycosis fungoides aimed to summarize their epidemiological and clinical characteristics and assess the effectiveness and safety of different treatment regimens. Clinical manifestations were further classified into 3 morphological groups: hypopigmented lesions, papules overlying hypopigmented lesions, and erythematous plaques overlying hypopigmented lesions. In addition, the results of this study suggest that interferon alpha might be an effective and well-tolerated therapy that could shorten the treatment time to complete response compared with other treatments. Maintenance therapy and long-term follow-up reduced the recurrence rate.

Paediatric Mycosis Fungoides: Clinical Variants, Treatment Modalities and Response to Therapy

Mycosis fungoides is a rare cutaneous lymphoma in the paediatric population. The aim of this study was to examine the epidemiological, clinical, and histological characteristics, as well as the treatment modalities and response to therapy of paediatric patients with mycosis fungoides. This retrospective cohort study reviewed the records of 37 paediatric patients treated at Rambam Medical Center, Israel, between 2013 and 2021. Extracted data included epidemiology, clinical presentation, histological reports, infiltrate clonality status, treatment modalities and response to therapy. The mean follow-up period was 60 months. All patients were diagnosed with stage IA or IB disease. Folliculotropic mycosis fungoides was the most prevalent variant (49%). Most patients were treated with phototherapy (90%), with a response rate of 85%, and a complete response rate of 55% after the first course. There were no significant differences in response to phototherapy between the folliculotropic or other variants (p = 0.072). Similarly, delayed diagnosis, atopic diathesis, clonality, phototherapy type or number of treatments, were not associated with response to therapy, while protracted phototherapy was associated with prolonged remission. In conclusion, mycosis fungoides in the paediatric population is an indolent disease with a favourable prognosis and potentially prolonged response to phototherapy.

Folliculotropic Mycosis Fungoides: Current Guidance and Experience from Clinical Practice

Introduction

Folliculotropic mycosis fungoides (FMF) is the most frequent variant of mycosis fungoides (MF), with clinical features which differ from the classic form. As for therapeutic options, the latest guidelines on MF agree on a stage-driven strategy, in consideration of clinical presentation, symptom burden and patient’s comorbidities.

Materials and Methods

A search on MEDLINE, PubMed, Scopus and Cochrane Library was conducted to gather the latest evidence on FMF clinical management. Manuscripts published in the last five years (January 2017–April 2022) were included. Our single-center experience was also described.

Results

A total of 15 articles were analyzed, with a total of 432 patients (disease stage from IA to IVA2). The most widely-used treatment was psoralen ultra-violet A (PUVA) in monotherapy or in association with other drugs. Oral retinoid-based therapy was also described as a therapeutic option alone or in combination. Other therapy reported were based on Brentuximab Vedotin, Mogamulizumab, Carmustine, topical steroids, tazarotene and excimer laser, interferon, nitrogen mustard, imiquimod, systemic chemotherapy, extracorporeal photopheresis and stem cell transplantation.

Discussion

FMF is characterized by specific clinical-pathologic features. Advanced forms assume characteristics more similar to classic MF (infiltrated plaques and nodules), whilst early stages can present in a wide range of clinical forms (acneiform lesions, follicular-like keratoses, erythematous patches). As for therapeutic options, in absence of specific guidelines, a high number of treatments are described in clinical practice, with variable results. Phototherapy in all its forms, especially as PUVA, appears to have the greatest initial therapeutic success. Retinoids, although widely used, appear to be poorly effective in monotherapy, particularly acitretin. Combination treatment with phototherapy seems to be advisable. Ionizing treatments, such as radiotherapy and TSEBT, appear effective, at least in the short term. Overall, an integrated approach is mandatory for the inconstant course of the disease and its multidisciplinary nature.

Hypopigmented Mycosis Fungoides: A Clinicopathological Review of 32 Patients

Background

Hypopigmented mycosis fungoides (hMF) is gradually acknowledged by more dermatologists, yet a consensus regarding its characteristics is not reached. The profile of Chinese hMF patients has not been deeply reviewed previously. Our research may contribute to the understanding of hMF, especially the Chinese patients with Fitzpatrick phototypes of III and IV.

Aim

To have a better understanding of hMF in terms of clinical, histopathological and immunohistochemical features in the Chinese population and to determine if there are differences between the Chinese population and other ethnic groups.

Methods

We made a retrospective analysis of clinical, histopathological and immunohistochemical features of 32 hMF patients in our hospital from 2010 to 2020. These features were then summarized and compared with previous reports.

Results

All patients belonged to Fitzpatrick phototypes of III or IV. Twenty-one male (65.63%) patients and 11 female (34.37%) patients were analyzed, and the male to female ratio was 1.9:1. The age at diagnosis of patients ranged from 4 to 39 years, and the average age at diagnosis of these patients was 18 years, the median age was 16.5. Back was the most frequent site (34.37%). The clinical and histological results of lesions had no distinctive points. Immunohistochemically, among these 32 patients, there were 30 patients whose information was complete, there was 19 patients (63.33%) who were CD8 positive lymphocytes predominance, 9 patients (30%) had CD8 and CD4 positive lymphocyte mixed infiltration, and other 2 patients (6.67%) had CD4 positive lymphocytes predominance. Partial loss of CD7 was only observed in 1 patient (3.33%). Nearly all patients adopted topical nitrogen mustard and topical steroid and most of them had an excellent prognosis.

Conclusion

The clinical profiles of hMF in Chinese population shared differences with other ethnic groups, but its histopathological, immunohistochemical results and prognosis condition were resembled with other previous reports. Hence, more patients were needed to find the characteristics of hMF.