Prolonged Complete Response with Lenalidomide in a Relapsed Diffuse Large B-Cell Lymphoma, Leg-Type: A Case Report.

INTRODUCTION: For primary cutaneous diffuse large B-cell lymphoma, leg-type (PCDLBCL-LT), there are no uniform recommendations for second-line treatment in case of relapse. CASE PRESENTATION: Here, we present the case of an elderly relapsed/refractory PCDLBCL-LT patient who obtained a prolonged clinical complete remission with lenalidomide. CONCLUSION: Lenalidomide as single agent led to an unexpected long complete response with manageable toxicity.

Primary Cutaneous B-Cell Lymphomas with Large Cell Morphology: A Practical Review.

Most primary cutaneous lymphomas consist of T-cell lymphomas or small cell lymphomas; however, the skin may also be affected by lymphomas with large cell morphology, as a primary or secondary localization. A minority of cases consist of primary cutaneous B-cell lymphomas (PCBCLs). PCBCLs are a heterogeneous group of rare neoplasms with an overlapping morphological and immunohistochemical picture of the different subtypes. Nevertheless, differential diagnosis in the setting of this group of neoplasms is mandatory to identify the correct therapy and prognosis, but it may be challenging since, due to the rarity of these neoplasms, they may not always be familiar to pathologists. Indeed, immunohistochemistry may not be enough to distinguish the different histotypes, which overlap in immunohistochemical features. Furthermore, the ever-increasing knowledge of the molecular features of systemic B-cell lymphomas, such as gene rearrangements with clinical significance, has led in recent years to further investigation into the molecular landscape of PCBCLs with large cell morphology. This work aimed to provide a practical diagnostic guide for pathologists dealing with primary cutaneous large B-cell lymphomas.

Radiotherapy as a Treatment Option for Local Disease Control in Primary Cutaneous Diffuse Large B-Cell Lymphoma, Leg Type.

BACKGROUND: Primary cutaneous diffuse large B-cell lymphoma, leg type (PCDLBCL, LT) is an aggressive lymphoma variant. Anthracycline-based chemotherapy with rituximab is recommended as first-line treatment. Radiotherapy (RT) has been considered as a therapeutic option for local disease control in patients with solitary or localized lesions. METHODS: We report the results of a retrospective analysis of PCDLBC, LT patients treated either with RT alone or with physician's decision as first-line treatment, aiming to assess disease progression and/or first recurrence in these treatment groups. RESULTS: We retrospectively analyzed 20 patients treated either with RT alone (n = 8) or with investigator's choice treatment (n = 12), which included chemotherapy alone or combined with local therapy (RT and wide local excision). Complete response (CR) was achieved in 8 patients from the first group and 9 patients from the second group, with 1 treatment failure. Six patients treated with RT alone progressed with a median time to progression (TTP) of 12.5 months. In the second group, 5 patients progressed with a median TTP of 5.2 months. RT showed good local disease control in both groups without any skin relapses during the follow-up period. CONCLUSION: RT as first-line monotherapy followed by watchful waiting did not significantly improve the overall risk of disease progression but resulted in good local disease control. After progression, RT could still easily be combined with systemic treatment. The strength of this analysis needs to be evaluated in a larger patient cohort.

Outcomes in primary cutaneous diffuse large B-cell lymphoma, leg type.

Primary cutaneous diffuse large B-cell lymphoma, leg type (PCDLBCL, LT) is a rare, aggressive lymphoma characterized by skin involvement predominantly in the lower extremities. Immunochemotherapy with or without involved-site radiation therapy (ISRT) is considered standard front-line therapy. Over-expression of PD-L1/PD-L2 is seen in a high proportion of PCDLBCL, LT cases, but efficacy of immune checkpoint inhibitors (ICI) in relapsed/refractory, PCDLBCL, LT has not been thoroughly studied. We conducted a retrospective cohort study of patients diagnosed with PCDLBCL, LT seen at Mayo Clinic from 1 January 2000 to 31 December 2020. Using the Kaplan-Meier method, we calculated progression-free survival, duration of response, and overall survival in patients who received front-line rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) with and without ISRT, and salvage ICI therapy for relapsed/refractory disease. A total of 28 patients with PCDLBCL, LT were identified. The median PFS in patients treated with R-CHOP plus ISRT was 58 months (95% CI: 18-112) compared to 14 months (95% CI: 5-not reached; p = 0.04) in those treated with R-CHOP without ISRT. The median PFS from salvage ICI therapy was 10 months (95% CI: 4-not reached), and median DOR from salvage ICI therapy was 23 months [95% CI: 4-26]. R-CHOP with ISRT had a significantly longer median PFS compared to R-CHOP without ISRT as front-line therapy for PCDLBCL, LT. ICIs may have a role in treating relapsed/refractory disease as reasonable activity in heavily pre-treated patients was observed in this study.

Primary cutaneous large B-cell lymphomas: relevance of the 2017 World Health Organization classification: clinicopathological and molecular analyses of 64 cases.

AIMS: We applied the 2017 World Health Organization (WHO) classification criteria to categorise a series of 64 primary cutaneous large B-cell lymphomas (PCLBCLs), containing a majority (≥80%) of large cells and a proliferative rate of ≥40%, raising the problem of the differential diagnosis between PCLBCL, leg type (PCLBCL-LT) and primary cutaneous follicle centre lymphoma, large cell (PCFCL-LC). The aims were to determine the reproducibility and prognostic relevance of the 2017 WHO criteria. METHODS AND RESULTS: Morphology and phenotype identified 32 PCLBCLs-LT and 25 PCFCLs-LC; seven cases (11%) remained unclassified. Morphology was less reproducible than immunophenotype. Pertinent markers for the differential diagnosis were MUM1, FOXP1, CD10, and IgM. bcl-2 and bcl-6 were expressed by both PCFCLs-LC and PCLBCLs-LT at substantial levels. Neither Ki67 expression nor p63 expression was of diagnostic value. MYD88 was found to be mutated only in PCLBCLs-LT (n = 22, 69%). According to Hans/Hans modified algorithms, 23 of 25 PCFCLs-LC had germinal centre (GC) status, and the 32 PCLBCLs-LT had non-GC status. Overall survival was poorer for PCLBCLs-LT than PCFCLs-LC (P = 0.0002). Non-GC cases had poorer overall survival than GC cases (P = 0.0007). In PCLBCLs-LT, MYC expression was associated with cutaneous relapses (P = 0.014). When GC/non-GC status was applied to unclassified cases, only a single case remained discordant. CONCLUSIONS: Our results support the 2017 WHO classification criteria for PCLBCL diagnosis. The Hans modified algorithm using CD10 and MUM1 distinguished PCFCLs-LC from PCLBCLs-LT with optimal diagnostic value without requiring bcl-6 immunolabelling (poorly reproducible). Rare unclassified cases may constitute a provisionally heterogeneous subgroup for which GC/non-GC status (relevant for prognosis) may guide therapeutic decisions.

Composite cutaneous lymphoma of diffuse large B-cell lymphoma-leg type and subcutaneous panniculitis-like T-cell lymphoma.

Composite lymphoma (CL) is a rare disease defined by the occurrence of two distinct lymphomas within a single tissue at the same time. We present the case of an 89-year-old male with a clinical history of immunoglobulin M monoclonal gammopathy of undetermined significance. The patient presented cutaneous eruption of nodules on the right bottom and arm. An excisional biopsy revealed cutaneous infiltration composed of two components. The first one consisted of large B-cells with CD20+/MUM1+/BCL2+ phenotype whereas the second one involved the subcutaneous fat in a panniculitic manner, and was CD3+/CD8+/granzyme B+/TCRßF1+. The final diagnosis was CL of primary cutaneous large B-cell lymphoma-leg type (PCLBCL-leg type) and subcutaneous panniculitis-like T-cell lymphoma (SPTCL). We report and characterize for the first time coexistent PCLBCL-leg type and SPTCL in a patient.

Molecular Mechanisms of Disease Progression in Primary Cutaneous Diffuse Large B-Cell Lymphoma, Leg Type during Ibrutinib Therapy.

Primary cutaneous diffuse large B-cell lymphoma, leg type (PCDLBCL-LT) is one of the well-recognized extranodal lymphomas commonly addicted to the B-cell receptor-MYD88 superpathway. We aimed to describe the genomic changes in a patient who progressed through treatment with ibrutinib, a Bruton's tyrosine kinase (BTK) inhibitor. An 80-year-old woman presented with multiply relapsed PCDLBCL-LT after multiple lines of chemoimmunotherapy and radiotherapy. Pre-treatment testing of the localized cutaneous tumor lesion on a lymphoid amplicon panel demonstrated an MYD88 p.L265P mutation. Ibrutinib therapy was subsequently commenced, resulting in complete resolution of the skin disease. Despite an ongoing skin response, the patient developed progressive nodal disease at two months. Genomic analysis of the cutaneous tumor sample at baseline was compared to that of the inguinal lymph node upon progression, and revealed the acquisition of multiple genomic changes. These included several aberrations expected to bypass BTK inhibition, including two CARD11-activating mutations, and a deleterious mutation in the nuclear factor kappa B (NF-κB) negative regulator, NFKBIE. In addition, an IgH-IRF8 translocation was detected (which brings the IRF8 transcription factor under control of the immunoglobulin heavy chain locus), representing a third plausible mechanism contributing to ibrutinib resistance. Several copy-number changes occurred in both samples, including an amplification of 18q, which encodes the anti-apoptotic protein BCL2. We describe the first case of novel genomic changes of PCDLBCL-LT that occurred while on ibrutinib, providing important mechanistic insights into both pathogenesis and drug resistance.

Primary cutaneous B-cell lymphomas with large cell predominance-primary cutaneous follicle center lymphoma, diffuse large B-cell lymphoma, leg type and intravascular large B-cell lymphoma.

In this review, we present clinical features and detailed histopathologic, immunologic, and molecular information regarding primary cutaneous follicle center lymphoma and primary cutaneous diffuse large B-cell lymphoma, leg type which together represent two of the three most common types of primary cutaneous B-cell lymphoma recognized in the current WHO classification system.1,2 Overall, B-cell lymphomas represent 19-27% of primary cutaneous lymphomas in most large European and American studies3-6 and together, primary cutaneous follicle center lymphoma and primary cutaneous diffuse large B-cell lymphoma, leg type account for approximately 2/3 to ¾ of these cases.5,7-11 Both subtypes can contain a high content of large B-lymphocytes, although most cases of primary cutaneous follicle center lymphomas exhibit a range in cell size and cytology. Intravascular large B-cell lymphoma, a less commonly-encountered EBV-negative primary cutaneous B-cell lymphoma composed of large cells, will be more briefly discussed in this report as well.

Primary cutaneous diffuse large B-cell lymphoma presenting as chronic non-healing ulcer.

Primary cutaneous diffuse large B-cell lymphoma is an uncommon and aggressive lymphoproliferative disorder with a rapid growth rate and dismal prognosis. We present the case of a 91-year-old female with an unusual manifestation of primary cutaneous diffuse large B-cell lymphoma, mimicking other more prevalent diseases like chronic non-healing venous ulceration. Dermatopathologic evaluation rendered the correct diagnosis. A discussion of this rare presentation is important for clinician consideration to prevent misdiagnosis and prolongation of proper management in patients with chronic non-healing leg ulcers.

[Diffuse large B-cell lymphoma with concomitant c-MYC and BCL6 gene rearrangements with primary skin involvement: A case report and a review of literature]. / Diffuznaia V-krupnokletochnaia limfoma s sochetannoi rearanzhirovkoi genov c-MYC i BCL6 s pervichnym porazheniem kozhi: sobstvennoe nabliudenie i obzor literatury.

Double-hit lymphoma (DHL) is a rare aggressive B-cell lymphoma with concomitant c-MYC, BCL2 or BCL6 gene rearrangements, which is characterized by the high frequency of extranodal lesions and by resistance to chemotherapy. The median survival does not exceed 18 months in patients with this disease. The majority of DHL is represented by с-MYC/BCL2 cases. The combination of c-MYC/BCL6 occurs rarely (5-8%). The paper describes a case of DHL with concomitant c-MYC and BCL6 gene rearrangements, which mimics diffuse large B-cell lymphoma, leg-type.

Aggressive primary cutaneous B-cell lymphomas show increased Angiopoietin-2-induced angiogenesis.

Primary cutaneous large B-cell lymphomas, leg type (PCLBCL/LT) are primary cutaneous B-cell lymphoma (PCBCL) with an intermediate prognosis. Therefore, antracycline-based polychemotherapy combined with rituximab has been recommended as first-line treatment. Yet, despite this regimen, the 5-year survival rate remains 50-66% only. Angiogenesis, the formation of a vascular network, is essential for the pathogenesis of nodal lymphomas. So far, no study has analysed angiogenesis and its key factors in PCLBCL/LT. The present study was aimed at characterizing angiogenesis in PCLBCL/LT to identify the angiogenic molecules as potential therapeutic targets. The intra-tumoral microvessel density (MVD) was assessed by immunohistochemical studies of CD20 and CD31. The MVD was higher in PCLBCL/LT compared with indolent PCBCL. Analyses of open-source microarray data showed correlation between the angiogenic molecule angiopoietin-2 (Ang-2) and pan-endothelial cell markers. ELISA studies determined a shift between Ang-2 and Ang-1 towards Ang-2 in the peripheral blood of PCLBCL/LT patients. Immunofluorescence costainings against the Ang receptor Tie2/angiogenic integrins/CD34 revealed that the vasculature in both aggressive and indolent PCBCL tumors harbours an endothelial cell subpopulation with reduced expression of Tie2. In contrast, the alternative Ang-2 binding partners, angiogenic integrins, are strongly expressed in PCBCL. In line with these findings, downstream targets of Ang-2-integrin signalling, that is phosphorylation of focal adhesion kinase at Tyr397, and sprouting angiogenesis are enhanced in PCLBCL/LT. Our data present Ang-2 as a promising therapeutic target and anti-angiogenic therapy as a new line in treatment of PCLBCL/LT as a hitherto intractable disease.

Atypical clinicopathologic presentation of primary cutaneous diffuse large B-cell lymphoma, leg type.

BACKGROUND: Primary cutaneous diffuse large B-cell lymphoma, leg type (cDLBCL-LT) is a well-defined entity of cutaneous B-cell lymphoma affecting predominantly elderly patients, mostly women. The typical clinical presentation is characterized by solitary or multiple, rapidly growing plaques or tumors on 1 leg (rarely both legs). OBJECTIVE: We sought to describe a new clinical variant of cDLBCL-LT that deviates from the conventional one. METHODS: Clinical, histopathologic, phenotypical, and molecular features of 3 cases of cDLBCL-LT presenting with patches or thin plaques were reviewed (all were women, aged 60, 62, and 87 years; lesions were located on the leg in all patients). RESULTS: These patients presented with patches or thin plaques that represented the first manifestation of cDLBCL-LT. All 3 patients reported a history of long-standing lesions (present for 6, 9, and 18 months, respectively). Histology revealed moderately dense, perivascular infiltrates of small lymphocytes admixed with variable numbers of large cells that were CD20(+), Bcl-2(+), and MUM-1(+). LIMITATIONS: There were only a small number of cases. CONCLUSIONS: We reported an unusual clinical presentation of cDLBCL-LT that deviates from the conventional one and that represents a formidable diagnostic challenge. Biopsy specimens of unusual patches/thin plaques or annular lesions should be obtained from the legs of adult patients if the lesions do not respond to conventional treatment.

Spontaneous regression of primary diffuse large B-cell lymphoma, leg type.

Primary cutaneous diffuse large B-cell lymphoma, leg type (PCLBCL LT) accounts for approximately 20% of all primary cutaneous B-cell lymphomas and tends to present as infiltrated nodules, tumors, and plaques on the legs in the elderly. Unlike other primary cutaneous large B-cell lymphomas, it has a poor prognosis and tends to require treatment with systemic chemotherapy. We present the case of an 82-year-old patient with a 1-year history of nodules and plaques on her right leg. Biopsy led to a diagnosis of PCLBCL LT and the lesions resolved without treatment within 1 month of the first visit. This is an atypical course of PCLBCL LT and we believe that it is the first such case to be reported in the literature.

Rituximab in the treatment of primary cutaneous B-cell lymphoma: a review.

Rituximab is a chimeric mouse-human antibody that targets the CD20 antigen, which is found in both normal and neoplastic B cells. In recent years, it has been increasingly used to treat cutaneous B-cell lymphoma and is now considered an alternative to classic treatment (radiotherapy and surgery) of 2 types of indolent lymphoma, namely, primary cutaneous follicle center lymphoma and primary cutaneous marginal zone B-cell lymphoma. Rituximab is also administered as an alternative to polychemotherapy in the treatment of primary cutaneous large B-cell lymphoma, leg type. Its use as an alternative drug led to it being administered intralesionally, with beneficial effects. In the present article, we review the literature published on the use of rituximab to treat primary cutaneous B-cell lymphoma.

Cutaneous B-Cell Lymphomas.

Primary cutaneous B-cell lymphomas represent a type of non-Hodgkin's lymphoma of the skin without evidence of extracutaneous involvement at the time of diagnosis. According to the 2018 World Health Organization-the European Organization for Research and Treatment of Cancer classification, primary cutaneous B-cell lymphomas include primary cutaneous marginal zone lymphoma, primary cutaneous follicle center lymphoma, primary cutaneous diffuse large B-cell lymphoma, leg type, intravascular large B-cell lymphoma, and Epstein-Barr virus+ mucocutaneous ulcer (provisional). Herein, we provide a comprehensive review of the updated literature on these entities, including clinical presentation, histopathology, immunophenotype, molecular genetics, prognosis, and treatment.

Primary cutaneous B-cell lymphomas: part II. Therapy and future directions.

The choice of therapy for primary cutaneous B-cell lymphoma (PCBCL) relies on correct histopathologic classification and the exclusion of systemic disease. In part II of this continuing medical education article, we will review the available therapies for the different types of PCBCL. Primary cutaneous follicle center lymphoma (PCFCL) and primary cutaneous marginal zone lymphoma (PCMZL) are indolent tumors with an excellent prognosis. They are managed similarly with local therapy, such as radiotherapy or surgical excision, for isolated disease and observation for asymptomatic multifocal presentations. Relapses are common in both PCFCL and PCMZL, but overall survival remains excellent. Primary cutaneous diffuse large B-cell lymphoma (both leg type and other) has a much poorer prognosis than indolent PCBCL, and it often requires an aggressive approach with radiation therapy and/or multiagent chemotherapy. Investigational approaches hold promise for the treatment of these malignancies, particularly primary cutaneous diffuse large B-cell lymphoma.

Primary cutaneous B-cell lymphomas: part I. Clinical features, diagnosis, and classification.

Primary cutaneous B-cell lymphomas (PCBCLs) are defined as lymphomas with a B-cell phenotype that present in the skin without evidence of systemic or extracutaneous disease at initial presentation, after adequate staging. In non-Hodgkin lymphomas, the skin is the second most common site of extranodal involvement after the gastrointestinal tract. PCBCLs are histologically very similar to their nodal counterparts, and these histologic similarities can lead to confusion about both therapy and prognosis. This article will summarize the clinical, pathologic, and diagnostic features of the 3 main types of PCBCL: primary cutaneous follicle center lymphoma, primary cutaneous marginal zone lymphoma, and primary cutaneous diffuse large B-cell lymphoma, leg-type, and the appropriate evaluation and staging procedures for each of these entities.

CD5+ Primary Cutaneous Diffuse Large B-Cell Lymphoma, Leg Type, Presenting as an Asymptomatic Nodule.

Primary cutaneous diffuse large B-cell lymphoma, leg type (PCDLBCL-LT), is a rare and aggressive variant of primary cutaneous lymphoma that typically expresses B cells as well as MUM1/IRF4, BCL2, and FOXP1, whereas BCL6 may be present or undetectable. We present a case of CD5+ PCDLBCL-LT presenting as a 6 mm pink-bluish nodule on the mid-left thigh, which was concerning for basal cell carcinoma. The histological examination reveals the presence of an intradermal proliferation of large, atypical CD5+, CD20+ BCL2+, BCL6+, MUM-1+, and Cyclin-D1+ lymphocytes in a nodular, diffuse interstitial and perivascular distribution. Because the patient presented with a small, single nodule, the systemic treatment of multiagent chemotherapy was avoided and localized electron beam radiation therapy with rituximab was initiated instead, achieving complete response. Early identification of PCDLBCL-LT is key for maximal therapeutic benefit and prognosis; it is important to consider PCDLBCL-LT on the differential when evaluating small, single nodules on the lower extremities of elderly patients.

Primary cutaneous large B cell lymphoma masquerading as lupus vulgaris.

Primary cutaneous large B cell lymphoma, leg type is a rare and aggressive variant of cutaneous B cell lymphoma. It predominantly affects elderly women, with the lower limb being the most common site of presentation. The overall prognosis is poor, compared to other cutaneous B cell lymphomas. A 47-year-old man presented with a progressively enlarging nodule over the medial aspect of the left foot since 2 months. Clinical examination revealed a nodular plaque-like lesion with central ulceration that measured 7 × 7 cm, firm in consistency, and with ill-defined margins. The initial clinical diagnosis was lupus vulgaris. An incision biopsy was done, which on histopathology and immunohistochemistry revealed a rare diagnosis of primary cutaneous B cell lymphoma, leg type. The patient was started on chemotherapy; however, he succumbed to his illness about 1 year after the initial presentation. It is a rare type of cutaneous lymphoma, which may masquerade infectious disorders such as lupus vulgaris. A detailed histopathological and immunohistochemical analysis is essential for its correct diagnosis and management. Only a handful of cases of this rare condition are reported to date. This case has been reported in view of its rarity and unusual clinical presentation.