Primary cutaneous indolent B-cell lymphomas - a retrospective multicenter analysis and a review of literature

A Descriptive Study of 103 Primary Cutaneous B-Cell Lymphomas: Clinical and Pathological Characteristics and Treatment from the Spanish Lymphoma Oncology Group (GOTEL)

Primary cutaneous B-cell lymphomas (PCBCLs) are B-cell lymphomas that can occur in the skin without evidence of extracutaneous involvement. The 2005 WHO/EORTC classification of cutaneous lymphomas and its 2018 update have distinguished three main categories based on clinicopathological, immunohistochemical, and genetic characteristics: primary cutaneous marginal zone lymphoma (PCMZL), primary cutaneous follicle centre lymphoma (PCFCL), and primary cutaneous diffuse large B-cell lymphoma, leg type (PCDLBCL-LT). PCMZL and PCFCL are clinically indolent, while PCDLBCL-LT is an aggressive lymphoma. Due to its low incidence and lack of prospective studies, it is difficult to establish a standard treatment for each subgroup. The objective of our study was to describe the clinical and pathological characteristics of 103 patients with cutaneous B-cell lymphoma from 12 centres belonging to the Spanish Lymphoma Oncology Group. The median age was 53 years (40-65). According to skin extension, 62% had single-site lymphoma, 17% had regional lymphoma, and 20% had multifocal lymphoma. Histology: 66% had PCMZL, 26% had PCFCL, and 8% had PCDLBCL-LT. Twenty-three percent of the patients were treated exclusively with surgery, 26% with radiotherapy only, 21% with surgery plus radiotherapy, 10% with polychemotherapy, and 5% with rituximab monotherapy. Overall, 96% of patients achieved a complete response, and 44% subsequently relapsed, most of them relapsing either locally or regionally. The 10-year OS was 94.5% for the entire cohort, 98% for the PCMZL cohort, 95% for the PCFCL cohort, and 85.7% for the PCDLBCL-LT cohort. Our data are comparable to those of other published series, except for the high frequency of PCMZL. The expected heterogeneity in therapeutic management has been observed.

An update on mechanisms of pruritus and their potential treatment in primary cutaneous T-cell lymphoma

Primary cutaneous T-cell lymphomas (CTCL), which include mycosis fungoides (MF) and Sézary syndrome (SS), are a group of lymphoproliferative disorders characterized by clonal accumulation of neoplastic T-lymphocytes in the skin. Severe pruritus, one of the most common and distressing symptoms in primary CTCL, can significantly impair emotional well-being, physical functioning, and interpersonal relationships, thus greatly reducing quality of life. Unfortunately, effectively managing pruritus remains challenging in CTCL patients as the underlying mechanisms are, as of yet, not fully understood. Previous studies investigating the mechanisms of itch in CTCL have identified several mediators and their corresponding antagonists used for treatment. However, a comprehensive overview of the mediators and receptors contributing to pruritus in primary CTCL is lacking in the current literature. Here, we summarize and review the mediators and receptors that may contribute to pruritus in primary CTCL to explore the mechanisms of CTCL pruritus and identify effective therapeutic targets using the PubMed and Web of Science databases. Studies were included if they described itch mediators and receptors in MF and SS. Overall, the available data suggest that proteases (mainly tryptase), and neuropeptides (particularly Substance P) may be of greatest interest. At the receptor level, cytokine receptors, MRGPRs, and TRP channels are most likely important. Future drug development efforts should concentrate on targeting these mediators and receptors for the treatment of CTCL pruritus.

Characteristics of Primary Cutaneous Lymphoma in Italy: A Tertiary Care, Single-Center Study

Data on primary cutaneous lymphomas (PCLs) patients in the Italian population are limited, and, despite the existence of several treatment options, the management of those patients remains challenging. Our study aimed to investigate the clinical and therapeutic features of PCL patients in a referral center in Italy. We conducted a retrospective study on 100 consecutive PCL patients between January 2017 and December 2022. The mean (SD) age of our cohort was 70.33 (14.14) years. Cutaneous T-cell lymphomas (CTCLs) represented 65% of all cases; the majority were mycosis fungoides (42%), followed by cases of Sezary syndrome (10%) and primary cutaneous anaplastic large cell lymphoma (4%). Cutaneous B-cell lymphomas (CBCLs) accounted for 35 % of PCLs, with 15 cases of primary cutaneous follicle center lymphoma, 10 cases of primary cutaneous diffuse large B-cell lymphoma leg type, and 9 cases of marginal zone B-cell lymphoma. A higher frequency of pruritus (p = 0.008) and higher peripheral blood levels of beta-2 microglobulin (p ≤ 0.001) and lactate dehydrogenase (p = 0.025) were found in CTCLs compared to those of CBCLs. Considering all therapeutic lines performed, treatments were extremely heterogeneous and skin-directed therapies represented the most frequently used approach. Our study confirms the distribution of PCL subtypes formerly reported in the literature and highlights the utility of real-life data in treatments to improve the current management of PCL patients.

The role of 18F-FDG PET/CT in primary cutaneous lymphoma: an educational review

INTRODUCTION

Primary cutaneous lymphoma (PCL) is a cutaneous non-Hodgkin's lymphoma that originates in the skin and lacks extracutaneous spread upon initial diagnosis. The clinical management of secondary cutaneous lymphomas is different from that of PCLs, and earlier detection is associated with better prognosis. Accurate staging is necessary to determine the extent of disease and to choose the appropriate treatment. The aim of this review is to investigate the current and potential roles of ¹⁸F- fluorodeoxyglucose positron emission tomography-computed tomography (¹⁸F-FDG PET/CT) in the diagnosis, staging, and monitoring of PCLs.

METHODS

A focused review of the scientific literature was performed using inclusion criteria to filter results pertaining to human clinical studies performed between 2015 and 2021 that analyzed cutaneous PCL lesions on ¹⁸F PET/CT imaging.

RESULTS & CONCLUSION

A review of 9 clinical studies published after 2015 concluded that ¹⁸F-FDG PET/CT is highly sensitive and specific for aggressive PCLs and proved valuable for identifying extracutaneous disease. These studies found ¹⁸F-FDG PET/CT highly useful for guiding lymph node biopsy and that imaging results influenced therapeutic decision in many cases. These studies also predominantly concluded that ¹⁸F-FDG PET/CT is more sensitive than computed tomography (CT) alone for detection of subcutaneous PCL lesions. Routine revision of nonattenuation-corrected (NAC) PET images may improve the sensitivity of ¹⁸F-FDG PET/CT for detection of indolent cutaneous lesions and may expand the potential uses of ¹⁸F-FDG PET/CT in the clinic. Furthermore, calculating a global disease score from ¹⁸F-FDG PET/CT at every follow-up visit may simplify assessment of disease progression in the early clinical stages, as well as predict the prognosis of disease in patients with PCL.

Treatment of Indolent Cutaneous B-Cell Lymphoma with Intralesional or Intravenous Rituximab

Simple Summary

Cutaneous B-cell lymphomas (CBCL) are a heterogeneous group of mature B-cells neoplasms that present in the skin without evidence of nodal or systemic involvement. Despite being indolent in nature, they tend to recur in a third of patients after treatment. As repetitive treatments may be necessary for patients with CBCL, there is a need for gentle non-invasive therapy. Rituximab is a medication that targets CD20, a receptor regularly expressed on CBCL, and thereby destroys the cancerous cells. This medication can be given as an infusion into the vein or as an injection directly into the skin tumors. In this study, we found that rituximab injections have a similar efficacy compared to infusions for patients with limited CBCL lesions.

Abstract

Indolent cutaneous B-cell lymphomas (CBCL) are a rare disease for which the therapeutic recommendations are based on clinical reports. Recommendations for solitary lesions include surgery or irradiation. However, the high relapse rates may require less invasive repeatable therapy. This study seeks to retrospectively assess the efficacy of intralesional rituximab (ILR) for indolent CBCL when compared with intravenous rituximab (IVR). Patients treated for indolent CBCL with ILR or IVR at the Division of DermatoOncology of the University Hospital Heidelberg were eligible for this study. Characteristics of lymphoma, treatment response, and adverse events were assessed. Twenty-one patients, 67% male at a median age of 52 (range 17–80), were included. Nineteen (90%) had only localized lymphoma (stage T1 and T2). Complete response was achieved in 92% (11/12) of ILR after a median of one cycle (three injections) and 78% (7/8) of IVR patients after a median of six cycles. Half of ILR patients and 78% of IVR patients showed relapse after a median of 15 and 23 months, respectively. Adverse reactions were usually mild and were limited to the first injection of ILR. One patient with IVR contracted a pulmonary infection. ILR may be an alternative to the intravenous administration of rituximab for localized indolent CBCL.

Update in Diagnosis and Management of Primary Cutaneous B-Cell Lymphomas

Primary cutaneous lymphomas are a rare group of diseases, with an estimated incidence of 0.5-1 case per 100,000 people per year. Primary cutaneous B-cell lymphomas (pCBCLs) represent 25-30% of all primary cutaneous lymphomas. There are three main subtypes of pCBCL: primary cutaneous marginal zone lymphoma, primary cutaneous follicle center lymphoma, and primary cutaneous diffuse large B-cell lymphoma, leg type. Cutaneous B-cell lymphomas have a broad spectrum of clinical presentations, which makes diagnostic and therapeutic strategies challenging. To date, treatment recommendations for cutaneous B-cell lymphomas have been largely based on small retrospective studies and institutional experience. Recently, the pharmacotherapeutic landscape has expanded to include drugs that may modify the underlying disease pathology of pCBCLs, representing new therapeutic modalities for this rare group of diseases. Novel therapies used for other systemic B-cell lymphomas show promise for the treatment of pCBCLs and are being increasingly considered. These new therapies are divided into five main groups: monoclonal antibodies, immune checkpoint inhibitors, small-molecule inhibitors, bispecific T-cell engaging, and chimeric antigen receptor T cell. In this review, we discuss the clinical, histopathological, molecular, and cytogenetic features of the most common pCBCL subtypes with a focus on current and innovative therapeutic developments in their management. These emerging treatment strategies for B-cell lymphomas and cutaneous B-cell lymphomas may represent novel first-line options for the management of these rare diseases.

Non Epitheliotropic B-Cell Lymphoma with Plasmablastic Differentiation vs. Cutaneous Plasmacytosis in a 12-Years-Old Beagle: Case Presentation and Clinical Review

Cutaneous lymphoid neoplasms and cutaneous plasmacytosis are rare in the dog; in human and in veterinary medicine, these have many clinical, cytological, histological, and phenotypic similarities, and a diagnosis of certainty is not easy. The aim of this study is to describe a case of cutaneous non epitheliotropic B-cell lymphoma (CNEBL) with plasmablastic differentiation vs. multiple cutaneous plasmacytosis (CP) in a dog, since the scarce bibliographic data on these topics. A 12-year-old male Beagle dog was presented for multiple, nodular, cutaneous, and subcutaneous, indolent masses disseminated on the whole body. Cytological, histological, flow cytometric, and immunohistochemical examinations, as well as complete radiographic evaluation, echocardiography, and abdominal ultrasound were performed. Cytology, histopathology, flow cytometric, and immunohistochemical examination, performed on the skin lesions, revealed a B-cell phenotype with plasmablastic differentiation. Nevertheless, a final diagnosis could not be achieved and it was categorized as a case of borderline CNEBL with plasmablastic differentiation versus CP. The dog was treated with a COP chemotherapeutic protocol. Total remission was obtained and relapse occurred 120 days later. To our knowledge, specific markers are actually unavailable to certainly differentiate CNEBL and CP in the dog and future studies are needed to improve knowledge on these pathologies in veterinary medicine, since prognosis and therapy are different.