Primary Cutaneous Follicle Center Lymphoma Research Articles

Cutaneous lymphomas—fast facts about an orphan disease—a short review

SummaryCutaneous lymphomas are a rare group of primary skin lymphoproliferative disorders, divided into T and B cell lymphomas. They differ substantially in clinical course and therapy. The two main subtypes of primary cutaneous T‑cell lymphomas include mycosis fungoides, which is the most common, and Sézary syndrome, the rare leukemic variant. Skin lesions seen in mycosis fungoides patients are erythematous patches, plaques, or tumors. Most patients remain at patch/plaque (early) stage, while some progress to tumor (advanced) stage during their clinical course. Sézary syndrome is characterized by erythroderma and involvement of lymph nodes and the peripheral blood. Treatment is dependent on the disease stage. Therapeutic options include skin-directed and systemic therapies. In localized, early stage mycosis fungoides, prognosis is usually good which changes in advanced stages. Significant progress has been made in recent years in the clinical management of progressive or relapsed cutaneous T‑cell lymphomas by the approval of new targeted therapies. Although there are no curative treatment options apart from allogeneic transplantation, response rates are often encouraging, in particular when using combination therapies. Primary cutaneous B cell lymphomas are rare and three main subtypes are recognized: primary cutaneous marginal zone lymphoma, primary cutaneous follicle center lymphoma, and primary cutaneous diffuse large B‑cell lymphoma, leg type. An accurate diagnosis of the subtype is important for therapeutic management. The most common clinical presentations are red-to-violaceous cutaneous nodules and papules. Primary cutaneous marginal and follicle center lymphoma have excellent 5‑year survival rates of 95–99%.

Follicle Center Lymphoma (FCL) of the Lower Female Genital Tract (LFGT): A Novel Variant of Primary Cutaneous Follicle Center Lymphoma (PCFCL).

Primary cutaneous follicle center lymphoma has been distinguished from nodal follicular lymphoma (FL) based on genomic and clinical features. The nature of other extranodal FLs is not well defined. We report 15 cases of follicle center lymphoma involving the lower female genital tract. Cases were evaluated using an immunohistochemical panel for B-cell lymphoma, B-cell clonality, fluorescence in situ hybridization for BCL2 gene rearrangement, and next-generation sequencing. All patients had localized disease with no evidence of bone marrow involvement. Most cases (12/15, 80%) had a follicular pattern, at least focally. Large centrocytes were a prominent feature leading to concern for diffuse large B-cell lymphoma by referring pathologists. Neoplastic cells were positive for CD20 and BCL-6, while BCL-2 was positive in 2/15 (13%) cases. Fluorescence in situ hybridization for BCL2 gene rearrangement was negative in 10/11 (91%) cases. Next-generation sequencing performed in 10 cases revealed TNFRSF14 as the most frequently mutated gene in 6/10 (60%) cases. No case had CREBBP or KMT2D mutations as seen in nodal FL. None of the patients had progressive disease with durable complete remission achieved in 10/12 (83%) cases. The median follow-up period was 7.8 years (range: 0.2 to 20.5y) with a 5-year overall survival of 100%. We conclude that follicle center lymphoma of the lower female genital tract is a novel variant of primary cutaneous follicle center lymphoma. Despite a frequent component of large cells, it is characterized by localized disease and low risk for dissemination. Awareness and recognition are important to distinguish these lesions from aggressive B-cell lymphomas.

433 Single-cell characterization of primary cutaneous B-cell lymphomas reveals distinct clonal properties of marginal zone, follicle center and leg-type lymphomas

Primary cutaneous B-cell lymphomas (CBCL) comprise a group of extranodal non-Hodgkin lymphomas that are primarily confined to the skin. Primary cutaneous marginal zone lymphoma (MZL) and follicle center lymphoma (FCL) are associated with a rather indolent tumor behavior, while diffuse large B-cell lymphoma, leg type (DLBCL-LT) shows an aggressive clinical course. Besides distinct clinical and immune-histological features, the underlying molecular tumor biology is still only insufficiently understood.

Panel Sequencing of Primary Cutaneous B-Cell Lymphoma.

Primary cutaneous follicular B-cell lymphoma (PCFBCL) represents an indolent subtype of Non-Hodgkin's lymphomas, being clinically characterized by slowly growing tumors of the skin and common cutaneous relapses, while only exhibiting a low propensity for systemic dissemination or fatal outcome. Up to now, only few studies have investigated underlying molecular alterations of PCFBCL with respect to somatic mutations. Our aim was to gain deeper insight into the pathogenesis of PCFBCL and to delineate discriminatory molecular features of this lymphoma subtype. We performed hybridization-based panel sequencing of 40 lymphoma-associated genes of 10 cases of well-characterized PCFBCL. In addition, we included two further ambiguous cases of atypical B-cell-rich lymphoid infiltrate/B-cell lymphoma of the skin for which definite subtype attribution had not been possible by routine investigations. In 10 out of 12 analyzed cases, we identified genetic alterations within 15 of the selected 40 target genes. The most frequently detected alterations in PCFBCL affected the TNFRSF14, CREBBP, STAT6 and TP53 genes. Our analysis unrevealed novel mutations of the BCL2 gene in PCFBCL. All patients exhibited an indolent clinical course. Both the included arbitrary cases of atypical B-cell-rich cutaneous infiltrates showed somatic mutations within the FAS gene. As these mutations have previously been designated as subtype-specific recurrent alterations in primary cutaneous marginal zone lymphoma (PCMZL), we finally favored the diagnosis of PCMZL in these two cases based on these molecular findings. To conclude, our molecular data support that PCFBCL shows distinct somatic mutations which may aid to differentiate PCFBCL from pseudo-lymphoma as well as from other indolent and aggressive cutaneous B-cell lymphomas. While the detected genetic alterations of PCFBCL did not turn out to harbor any prognostic value in our cohort, our molecular data may add adjunctive discriminatory features for diagnostic purposes on a molecular level.

Rituximab Treatment of Primary Cutaneous Follicle Center Lymphoma: A Retrospective Review.

Primary cutaneous B-cell lymphoma (PCBCL) presents only in the skin at the time of diagnosis with no evidence of extracutaneous disease, and primary cutaneous follicle center lymphoma (PCFCL) is the most common subtype. There is currently a lack of prospective randomized control trials and large retrospective studies investigating the efficacy of different treatment options for PCFCL. This retrospective study was conducted to describe our local clinical experience and outcomes of patients treated with rituximab-containing regimens. To describe our local clinical experience and treatment outcomes of patients treated with rituximab-containing regimens. A retrospective study consisting of 25 PCFCL patients treated with different modalities. Patient records were reviewed and analyzed using a Kaplan-Meier estimation and SAS 9.4 software. After the initial treatment, all patients had CR except for 1 patient in the observation group. Further, 60% of patients in surgery, 20% in chemoimmunotherapy, 67% in rituximab monotherapy, 33% in steroid injection/systemic prednisone, and 33% in observation experienced a relapse. Although no significant difference was found between treatment groups due to the small sample size, time to relapse trends provides insight into treatment responses. Chemoimmunotherapy had the lowest relapse rate in the first 5 years post-treatment, whereas surgery had a higher tendency to relapse. Despite the potential for rituximab-containing chemoimmunotherapy to yield adverse effects, it is effective in achieving a prolonged clinical remission in patients with PCFCL. It remains a reasonable treatment option for diffuse, extensive, or treatment-resistant disease.

32922 Intralesional rituximab for indolent primary cutaneous B-cell lymphoma

Primary cutaneous B-cell lymphoma (PCBCL) is a rare group of clonal B-cell lymphoproliferative disorders present in the skin. Two indolent forms of PCBCL are primary cutaneous follicle center lymphoma (PCFCL), and marginal zone B-cell lymphoma (PCMZL). The primary aim of this study was to analyze the outcomes of patients with PCBCL treated with intralesional rituximab. A retrospective search of patients with PCBCL treated with intralesional rituximab was performed across the Mayo Clinic enterprise.

32888 Primary cutaneous B-cell lymphoma treated with systemic rituximab

Primary cutaneous B-cell lymphoma (PCBCL) is a heterogenous group of rare extranodal non-Hodgkin lymphomas of the skin. This group includes primary cutaneous follicle center lymphoma (PCFCL), marginal zone B-cell lymphoma (PCMZL), and diffuse large B-cell lymphoma, leg type (PCDLBCL-LT). The objective of our study was to analyze the treatment protocol and outcomes of patients treated with systemic rituximab, in isolation or in combination with other chemotherapy, for PCBCL. A retrospective search for patients with PCBCL treated with rituximab in the Mayo Clinic enterprise was performed.

34030 Primary cutaneous follicle center lymphoma mimicking alopecia areata: A case report

Primary cutaneous follicle center lymphoma (pcFCL) is an indolent primary cutaneous B-cell lymphoma that most commonly occurs on the head (including scalp), neck, and back. pcFCL typically presents as a solitary to multiple erythematous nodule(s) or plaque(s). The authors present a case of atypical pcFCL in a 65-year-old woman manifesting as 2 discrete erythematous alopecic patches on the scalp, grossly resembling new-onset alopecia areata. Multiple punch biopsies with immunohistochemical (IHC) staining followed by flow cytometry were performed.

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.

Multiple skin-colored facial papules in a child

Multiple skin-colored facial papules in a child

Abstract 4129: Descriptors of primary cutaneous follicular helper T-cell lymphoma (PCFHTCL): Analysis of a pooled database of a rare entity

Abstract Introduction: Primary Cutaneous Follicular Helper T-cell Lymphoma (PCFHTCL) is a rare cutaneous T-cell lymphoma that was recently described. PCFHTCL is comprised of small to medium lymphocytes that express CD4, CD19, Bcl6, PD1, ICOS, CXCR5, and CXCL13. While it tends to have mostly an indolent course, occasionally PCFHTCL may display a more aggressive pattern. We conducted this analysis to explore the key clinicopathologic characteristics of this rare and little-known entity. Methods: In order to study the demographic characteristics, molecular and immunohistochemical signatures, therapeutic interventions, survival, and prognostic factors, we compiled a pooled database of 57 cases. Kaplan-Meier survival curves were constructed. Cox proportional-hazards model and Log-rank tests were used to assess the influence of demographic and clinicopathologic factors on overall survival and disease-free survival. Results: A total of 57 patients with confirmed PCFHTCL were identified. The median age was 57 years with a peak incidence between ages 53 and 64. There was a male predominance with an M:F ratio of 1.25. PCFHTCL commonly involved the head (54%), followed by the torso (24%) and limbs (12%). Sixteen percent of the lesions were solitary and mostly involved the head. The most common pattern was nodular/tumorous. Histologically, PCFHTCL involved mainly the dermis with occasional focal epidermotropism (27%), folliculotropism (43%), syringotropism (7%), and subcutaneous extension (14%). Extracutaneous involvement comprised lymph nodes (11%), bone marrow (4%), and the peripheral blood (2%). The median duration of symptoms prior to diagnosis was 5 months. The six-year disease-free survival is around 85%. Surgical resection alone resulted in durable remission in 40% of the cases. Recurrent disease was successfully salvaged with re-resection, radiation, and chemotherapy. While solitary lesions tended to have a better disease-free survival, it did not reach statistical significance. Conclusions: This study represents the largest cohort of this rare cutaneous T-cell entity. It describes the demographic and clinical patterns of disease presentation and provides a detailed update on the clinicopathologic features PCFHTCL. Citation Format: Philip A. Haddad, Dalia Hammoud, Kevin Gallagher. Descriptors of primary cutaneous follicular helper T-cell lymphoma (PCFHTCL): Analysis of a pooled database of a rare entity [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 4129.

BCL‐2 expression in primary cutaneous follicle center lymphoma is associated with a higher risk of cutaneous relapses: A study of 126 cases

<scp>BCL</scp>‐2 expression in primary cutaneous follicle center lymphoma is associated with a higher risk of cutaneous relapses: A study of 126 cases

H3K27m3 overexpression as a new, BCL2 independent diagnostic tool in follicular and cutaneous follicle center lymphomas

Approximately 15% of follicular lymphomas (FL) lack overexpression of BCL2 and the underlying translocation t(14;18). These cases can be diagnostically challenging, especially regarding follicular hyperplasia (FH). In a subset of FL, mutations in genes encoding for epigenetic modifiers, such as the histone-lysine N-methyltransferase EZH2 (enhancer of zeste homolog 2), were found, which might be used diagnostically. These molecular alterations can lead to an increased tri-methylation of histone H3 at position lysine 27 (H3K27m3) that, in turn, can be visualized immunohistochemically. The aim of this study was to analyze the expression of H3K27m3 in FL, primary cutaneous follicle center lymphomas (PCFCL), and pediatric-type FL (PTFL) in order to investigate its value in the differential diagnosis to FH and other B cell lymphomas and to correlate it to BCL2 expression and the presence of t(14;18). Additionally, the mutational profile of selected cases was considered to address H3K27m3’s potential use as a surrogate parameter for mutations in genes encoding for epigenetic modifiers. Eighty-nine percent of FL and 100% of PCFCL cases overexpressed H3K27m3, independently of BCL2, EZH2, and the presence of mutations. In contrast, 95% of FH and 100% of PTFL cases lacked H3K27m3 overexpression. Other B cell lymphomas considered for differential diagnosis also showed overexpression of H3K27m3 in the majority of cases. In summary, overexpression of H3K27m3 can serve as a new, BCL2 independent marker in the differential diagnosis of FL and PCFCL, but not PTFL, to FH, while being not of help in the differential diagnosis of FL to other B cell lymphomas.

Primary Cutaneous B-Cell Lymphoma: An Update on Pathologic and Molecular Features

Primary cutaneous B-cell lymphomas (PCBCLs) account for 25% of all primary cutaneous lymphomas. Three major types are currently recognized by the WHO classification: primary cutaneous marginal zone B-cell lymphoma (PCMZL), primary cutaneous follicle centre lymphoma (PCFCL) (both considered indolent lymphomas) and primary cutaneous diffuse large B-cell lymphoma, leg-type (PCDLBCL-LT), which is, instead, a very aggressive disease. Nowadays, the PCBCL’s category also includes some rare entities such as intravascular B-cell lymphoma (IVBL) and the EBV+ mucocutaneous ulcer (EBVMCU). Furthermore, controversies still exist concerning the category of primary cutaneous diffuse large B-cell lymphoma (PCDLBCL), because some cases may present with clinical and histological features between PCFCL and PCDLBCL-LT. Therefore, some authors proposed introducing another category called PCDLBCL, not otherwise specified (NOS). Regardless, PCBCLs exhibit distinct features and differ in prognosis and treatment from their nodal/systemic counterparts. Therefore, clinicopathologic analysis is a key diagnostic element in the work-up of these lymphomas.

Integrative diagnosis of primary cutaneous large B-cell lymphomas supports the relevance of cell of origin profiling.

Primary cutaneous large B-cell lymphomas (PCLBCL) represent a diagnostic challenge because they are classified as PCLBCL, leg type (PCLBCL, LT) or primary cutaneous follicle centre lymphoma, large cell (PCFCL, LC), which differ by prognosis and therapeutic requirement. Unclassified cases with discordant clinical presentations, morphologies, and immunophenotypes may be classified into the not otherwise specified (PCLBCL, NOS) category based on ancillary molecular analyses. Cell-of-origin profiling as germinal centre (GC) type or non-GC type by immunohistochemistry is not considered reproducible because of variable CD10 expression. In a series of 55 PCLBCL cases with > 80% large cells, we reported 21 PCFCL, LC cases as GC-type and 27 PCLBCL, LT as non-GC-type; 7 cases were considered PCLBCL, NOS. Here, we demonstrate the accuracy of molecular profiling of PCLBCL as GC or non-GC type using a reverse transcriptase multiplex ligation assay (RT-MLPA). RT-MLPA classified the seven PCLBCL, NOS cases in accordance with their mutational profile. An integrative principal component analysis confirmed the main criteria and the relevance of genomic profiling of PCFCL, LC as GC-derived, and PCLBCL, LT as non-GC-derived. Both the cell-of-origin classification of PCLBCL and the integrative analysis identified two clinically relevant subgroups according to overall survival, which may help to standardize PCLBCL diagnosis and patient management.

A Rare Case of Primary Cutaneous Follicle Center Lymphoma Mimicking Leprosy

Cutaneous B-Cell Lymphoma is a rare type of cutaneous lymphoma with a plethora of clinical manifestations ranging from macules, papules, nodules, or plaques. The lesions are often painless and certain subtypes such as the primary cutaneous follicle center lymphoma (PCFCL) are indolent. The disease is often misdiagnosed with other dermatoses including bacterial and fungal infections. Here we report a 55-year-old female patient with clinical manifestations resembling multibacillary leprosy that was then confirmed to be PCFCL through aid of dermoscopy and histopathology. The patient then undergone chemotherapy using the R-CHOP regiment which resulted in significant clinical improvement and no signs of metastases or extracutaneous involvement upon follow-up.

Immunohistochemical algorithms and gene expression profiling in primary cutaneous B-cell lymphoma

Objectiveto assess whether immunohistochemical (IHC) algorithms used to classify the cell of origin (COO) of nodal Diffuse Large B-cell lymphoma (nDLBCL) in Germinal Center type (GCB) and non-GCB subtypes may be applied to Primary Cutaneous B-cell lymphoma (PCBCL) too, and which of these algorithms performs better on PCBCL. DesignRetrospective case control study. SettingPathology Department of the University Hospital “San Giovanni di Dio e Ruggi d′Aragona” Salerno, Italy. ParticipantsFourteen PCBCL, including Primary Cutaneous follicle centre lymphoma (PCFCL) and primary cutaneous diffuse large B-cell lymphoma, Leg type (PCDLBCL-LT) and 14 nDLBCL were evaluated for 7-year period (January 2011 to December 2017). Primary cutaneous marginal zone cell lymphoma (PCMZL) cases were not included in the present study. InterventionEvaluation of immunohistochemical CD10, BCL6, MUM1/IRF4, BCL2, MYC and Ki-67 expression and classification according to three different algorithms. Gene expression profiling (GEP) was performed on the same series using Lymph2Cx assay (Nanostring). The data obtained were compared and analysed. ResultsAll the IHC algorithms showed 13 GCB and 15 non-GCB. GEP showed 12 GCB, 12 activated B cell–type and 4 unclassified. ConclusionsThe PCBCL were classifiable as GCB and non-GCB like the nDLBCL as IHC algorithms were concordant to GEP and produced the same results.

Cell-of-origin classification using the Hans and Lymph2Cx algorithms in primary cutaneous large B-cell lymphomas

Primary cutaneous diffuse large B-cell lymphoma, leg type (PCDLBCL-LT) and primary cutaneous follicle center lymphoma with a diffuse population of large cells (PCFCL-LC) are both primary cutaneous B-cell lymphomas with large-cell morphology (CLBCL) but with different clinical characteristics and behavior. In systemic diffuse large B-cell lymphoma, not otherwise specified (DLBCL-NOS), gene-expression profiling (GEP) revealed two molecular subgroups based on their cell-of-origin (COO) with prognostic significance: the germinal center B-cell-like (GCB) subtype and the activated B-cell-like (ABC) subtype. This study investigated whether COO classification is a useful tool for classification of CLBCL. For this retrospective study, 51 patients with PCDLBCL-LT and 15 patients with PCFCL-LC were analyzed for their COO according to the immunohistochemistry-based Hans algorithm and the NanoString GEP-based Lymph2Cx algorithm. In PCFCL-LC, all cases (100%) classified as GCB by both Hans and Lymph2Cx. In contrast, COO classification in PCDLBCL-LT was heterogeneous. Using Hans, 75% of the PCDLBCL-LT patients classified as non-GCB and 25% as GCB, while Lymph2Cx classified only 18% as ABC, 43% as unclassified/intermediate, and 39% as GCB. These COO subgroups did not differ in the expression of BCL2 and IgM, mutations in MYD88 and/or CD79B, loss of CDKN2A, or survival. In conclusion, PCFCL-LC uniformly classified as GCB, while PCDLBCL-LT classified along the COO spectrum of DLBCL-NOS using the Hans and Lymph2Cx algorithms. In contrast to DLBCL-NOS, the clinical relevance of COO classification in CLBCL using these algorithms has limitations and cannot be used as an alternative for the current multiparameter approach in differentiation of PCDLBCL-LT and PCFCL-LC.

Cutaneous B-cell lymphomas: Update on diagnosis, risk-stratification, and management

PCBCLs are a group of Non-Hodgkin's B-cell lymphomas originating in and usually confined to the skin, representing approximately one fourth of primary cutaneous lymphomas (PCL). Their current classification system has been the result of the joint World Health Organization (WHO) - European Organization for Research and Treatment of Cancer (EORTC) consensus in 2018. To date, several types of PCBCLs have been described in the scientific literature, with different clinical presentation and prognosis. Primary cutaneous follicle-center lymphoma (PCFCL) and primary cutaneous marginal zone lymphoma (PCMZL) are the most common forms, with a typical indolent course. On the contrary, primary cutaneous diffuse large B-cell lymphoma, leg type (PCDLBCL, LT) is less common, yet more aggressive, with a reported 5-year overall survival of approximatively 50%. In this review, we outline the PCBCLs defining diagnostic criteria, report the features of the less common subtypes and summarize the noteworthy therapeutical options currently available in this field.

A case of primary cutaneous follicle center lymphoma that recurred 5 years after the first diagnosis as pseudolymphoma

37歳，男性。2016年11月右前額部に紅色結節を生じた。病理では，真皮全層に小型リンパ球の密な浸潤がみられT細胞，B細胞は混在していた。偽リンパ腫と診断，ステロイド局注にて消退した。2021年8月より前額部の紅色結節再発。皮膚生検にて表皮から皮下脂肪織にかけて大型の異型細胞を混じる密な細胞浸潤がみられた。免疫グロブリンH鎖遺伝子再構成あり。免疫染色にて，CD20（＋）CD79a（＋）bcl－6（＋）bcl－2（－）MUM－1（－）で原発性皮膚濾胞中心リンパ腫（PCFCL）と診断。PETCT検査にて明らかな転移等認めず，ステロイド局注・放射線治療行い紅色結節は消退した。PCFCLは予後良好な皮膚原発のB細胞性リンパ腫であり，しばしば偽リンパ腫との鑑別が困難で，診断に難渋することがある。初回の組織学的所見が異型性に乏しく治療反応性が良好であっても慎重に経過を観察することが望ましい。