Primary Cutaneous Diffuse Large B-cell Research Articles

Classical Case of Primary Cutaneous Diffuse Large B-cell Lymphoma, Leg Type

Primary cutaneous diffuse large B-cell lymphoma, leg type (PCDLBCL-LT) usually occurs in elderly patients and in most cases affects lower legs. A 76-year old man presented with red-brown coloured patches and plaques with irregular borders and multiple firm nodes on the anterior surface of the right lower leg. The excision biopsy of a node and histological examination has confirmed the diagnosis of PCDLBCL-LT. Clinical, laboratory and radiological examination showed no evidence of systemic involvement. The treatment was started with R-CHOP (rituximab-cyclophosphamide, doxorubicin, vincristine and prednisone) regimen. The patient died within 10 months due to cardiac complications since the initial diagnosis.

TOX expression in cutaneous B-cell lymphomas.

Thymocyte selection-associated high-mobility group box (TOX) is aberrantly expressed in cutaneous T-cell lymphomas. In a recent study, TOX expression was noted unexpectedly in the follicle center (germinal center) B-cells of reactive lymph nodes and tonsils, used as external controls. To evaluate whether TOX is also expressed by cutaneous B-cell lymphomas, TOX immunohistochemistry was performed on skin biopsies of 44 patients with primary and secondary cutaneous B-cell proliferations. TOX was expressed not only in the reactive follicle center cells of lymph nodes, tonsils, cutaneous lymphoid hyperplasia, and primary cutaneous marginal zone lymphomas, but also by the neoplastic follicle center cells of 16/17 patients with primary cutaneous follicle center lymphoma (PCFCL) and 7/7 patients with cutaneous manifestations of systemic follicular lymphoma (FL). Notably, TOX showed a very similar expression pattern as BCL6, a marker of germinal center B-cells. In 4/10 patients with a BCL6+ primary cutaneous diffuse large B-cell lymphoma, leg type (PCDLBCL,LT) and in 2/2 patients with a secondary cutaneous BCL6+ diffuse large B-cell lymphoma (DLBCL), TOX was expressed by more than 50 % of the neoplastic B-cells. In contrast, in 3/3 BCL6− PCDLBCL,LT, TOX was completely negative or weakly expressed by a minor proportion of the neoplastic B-cells. In conclusion, TOX is expressed not only by neoplastic T-cells, but also by both reactive and neoplastic follicle center (germinal center) B-cells and a proportion of BCL6+ PCDLBCL,LT and secondary cutaneous BCL6+ DLBCL. The functional significance of TOX expression in reactive and neoplastic B-cells remains to be elucidated.

Skin Involvement of Mantle Cell Lymphoma May Mimic Primary Cutaneous Diffuse Large B-cell Lymphoma, Leg Type.

Mantle cell lymphoma (MCL) is a B-cell neoplasm with a variable and generally aggressive clinical course. So far our knowledge of skin involvement of MCL is limited. To understand the clinical and histopathologic features of MCL with skin involvement, the files of the Lymph Node Registry Kiel were screened for MCL diagnosed in the skin. Over a period of 13 years, 1321 biopsy specimens were diagnosed as MCL; among them, 14 patients (1%) showed skin involvement. Of these, skin was the initial site of manifestation in 6/11 (55%) cases. One patient presented with a skin-limited lymphoma. Furthermore, 7/12 (58%) patients presented with lesions on the leg. The lymphomas were highly proliferative with blastoid cytology in 12/14 (86%) cases. Moreover, the immunophenotype with expression of BCL2 (100%), MUM-1/IRF4 (83%), and IgM (82%) and lack of CD10 (25%) and BCL6 (0%) closely resembled the features of primary cutaneous diffuse large B-cell lymphoma, leg type. Solely the expression of cyclin D1 (100%) and the presence of t(11;14) (100%) allowed a distinction from cases of primary cutaneous diffuse large B-cell lymphoma, leg type. Only 2 MCL cases with skin involvement presented with classical cytology. Interestingly, in these 2 cases skin involvement occurred simultaneously in a lesion of coexisting primary cutaneous marginal zone lymphoma. Our data suggest that clinical presentation on the leg and blastoid cytology along with high proliferation and expression of Bcl2, Mum-1/IRF4, and IgM are typical for MCL involving the skin. Lymphomas with these features might be erroneously diagnosed as diffuse large B-cell lymphoma, leg type, if cyclin D1 staining is not performed.

B-Cell Lymphoma Mimicking Dermatitis: A Pitfall

Primary cutaneous diffuse large B-cell lymphoma, leg type (cDLBCL-LT) is frequently diagnosed in elderly women. As the name implies, it frequently

The High Expression of the microRNA 17–92 Cluster and its Paralogs, and the Downregulation of the Target Gene PTEN, Is Associated with Primary Cutaneous B-Cell Lymphoma Progression

The oncogenic microRNA (miR) 17-92 cluster has a causative role in the lymphomagenesis of nodal B-cell lymphomas, by activating proliferation and inhibiting apoptosis. Here we analyzed primary cutaneous B-cell lymphomas for the miR-17-92 cluster and its paralogs miR-106a-363 and miR-106b-25. In 22 primary cutaneous diffuse large B-cell lymphomas, leg type (PCLBCL-LT) compared with 22 primary cutaneous follicle center lymphomas (PCFCLs), we found that miR-20a and miR-106a were overexpressed. Multivariate Cox analysis showed that higher miR-20a and miR-20b expression levels were associated with shorter disease-free and overall survival, independently from histological type. Gene expression profiling also showed a downregulation of 8 candidate target genes of miR-20a, miR-20b, and miR-106a in PCLBCL-LT compared with PCFCL. Among the candidate target genes, PTEN, NCOA3, and CAPRIN2 were confirmed to be underexpressed in PCLBCL-LT using quantitative reverse transcriptase-PCR on CD20-positive laser-microdissected tumor cells. In multivariate Cox analysis, lower PTEN mRNA expression level was associated with shorter disease-free survival (DFS), independently from the histological type. Altogether, this molecular and bioinformatic study of 44 patient skin biopsy samples showed that the oncogenic miR-17-92 cluster and its paralogs were involved in cutaneous B-cell lymphoma progression, and that the downregulation of the target gene PTEN was associated with shorter DFS.

Complete response in a case of CD30+ primary cutaneous diffuse large B-cell lymphoma of the scalp treated with brentuximab vedotin

Complete response in a case of CD30+ primary cutaneous diffuse large B-cell lymphoma of the scalp treated with brentuximab vedotin

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

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). We sought to describe a new clinical variant of cDLBCL-LT that deviates from the conventional one. 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). 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(+). There were only a small number of cases. 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.

Primary cutaneous diffuse large B-cell lymphoma, leg type: a study of clinicopathology, immunophenotype and gene rearrangement

To study the clinicopathologic features, immunophenotype and gene rearrangement of primary cutaneous diffuse large B-cell lymphoma, leg type (PCLBCL). Seven cases of PCLBCL were enrolled into the study. Clinicopathologic analysis, immunohistochemical staining and gene rearrangement for IgH and Igκ were undertaken in the study. All the seven cases were male, and the median age was 72 years. Patients usually presented with multiple purple tumors, nodules, papules and infiltrative plaques. Two patients had a history of leg injury before onset, and one had mosquito bites. Histologically, the tumor involved the dermis and subcutis with dense and diffuse infiltrative pattern composing of centroblasts and/or immunoblasts. Immunohistochemical staining showed that seven cases (7/7) expressed CD20, six (6/6) expressed bcl-2, four (4/4) expressed MUM-1, four (4/5) expressed CD79a, four (4/5) expressed PAX-5 and four (4/6) expressed bcl-6, respectively. All cases did not express CD3ε, CD45RO, CD10 and CD30. IgH gene rearranged bands were detected in three (3/6) cases and Igκ was detected in one (1/5) case. Six of the seven cases died and the remaining patient, who was 44-year-old, was alive after 22 months of follow-up. PCLBCL is rare, predominantly affects elderly male patients. PCLBCL has poor prognosis and high mortality, but younger patients seem to have better prognosis. Some cases had a history of trauma or mosquito bites. The relationship between the history and the onset of PCLBCL needs further evaluation.

Clinical features and treatment outcomes of primary cutaneous B-cell lymphoma: a single-center analysis in South Korea.

Clinical features and treatment outcomes of primary cutaneous B-cell lymphoma (PCBCL) have rarely been reviewed, due to the rarity and pathologic obscurity of this disease. We reviewed 21 patients who were pathologically diagnosed with PCBCL from Samsung Medical Center's lymphoma cohort, following the WHO-EORTC classification system: primary cutaneous follicle-center lymphoma (PCFCL), primary cutaneous marginal zone lymphoma (PCMZL), primary cutaneous diffuse large B-cell lymphoma, leg type (PCLBCL, LT), and cutaneous diffuse large B-cell lymphoma, other (PCDLBCL, other). Of 2831 B-cell lymphoma cases, PCBCL comprised only 0.74 % of cases (N = 21, eight PCLBCL, LT (0.28 %), 10 PCMZL (0.35 %), two PCDLBCL, other (0.06 %), and one PCFCL (0.03 %)). Eighteen of 21 patients received treatment for PCBCL (12 chemotherapy alone, three radiotherapy alone, three chemotherapy following radiotherapy) and complete response (CR) was observed in 17 patients. The median progression-free survival was 44 months [95 % confidence interval (CI): 11-61 months]. Two patients had died at the time of analysis, with a median follow-up duration of 85 months [95 % confidence interval (CI): 55-118 months]. PCBCL cases in this study have a higher proportion of disseminated PCMZL and PCLBCL, LT, and excellent outcomes were observed with chemotherapy, including R-CHOP or R-CVP irrespective of staging and pathologic subtype.

Cutaneous B-cell lymphomas: 2015 update on diagnosis, risk-stratification, and management.

Approximately one-fourth of cutaneous lymphomas are B-cell derived and are generally classified into three distinct subgroups: primary cutaneous follicle center lymphoma (PCFCL), primary cutaneous marginal zone lymphoma (PCMZL), and primary cutaneous diffuse large B-cell lymphoma, leg type (PCDLBCL, LT). DIAGNOSIS and disease classification is based on histologic review and immunohistochemical staining of an appropriate skin biopsy. Pathologic review and an appropriate staging evaluation are necessary to distinguish primary cutaneous B-cell lymphomas from systemic B-cell lymphomas with secondary skin involvement. Risk-stratification: Disease histology remains the most important prognostic determinant. Both PCFCL and PCMZL are indolent lymphomas that infrequently disseminate to extracutaneous sites and are associated with 5-year survival rates that exceed 95%. In contrast, PCDLBCL, LT is an aggressive lymphoma with an inferior prognosis. PCFCL and PCMZL patients with solitary or relatively few skin lesions may be affectively managed with local radiation therapy. While single-agent rituximab may be employed for patients with more widespread skin involvement, multiagent chemotherapy is rarely appropriate. In contrast, management of patients with PCDLBCL, LT is comparable to the management of patients with systemic DLBCL.

High frequency and clinical prognostic value of MYD88 L265P mutation in primary cutaneous diffuse large B-cell lymphoma, leg-type.

The activating mutation of MYD88 L265P is a frequent feature of primary cutaneous diffuse large B-cell lymphoma, leg-type (PCLBCL-LT), reported in up to 69% of the cases. Whether patients with MYD88 mutation display specific clinical and evolutive features has not been evaluated. To identify the clinical characteristics associated with MYD88 mutation, confirm its high prevalence, and evaluate its effect on prognosis in patients with PCLBCL-LT. A retrospective multicenter study was conducted using the medical records of patients from dermatology departments belonging to the French Study Group for Cutaneous Lymphomas. Sixty-one patients with a diagnosis of PCLBCL-LT made between 1988 and 2010 who were available for molecular study were included. Of these, 58 patients displaying interpretable results constituted the study group. Median follow-up was 33 months, and 39 patients (67%) were monitored until death. Clinical features (age, sex, number of skin lesions, tumor stage, and location as leg vs elsewhere), MYD88 mutation (allele-specific TaqMan polymerase chain reaction assay), treatment regimen, and outcome were recorded. Baseline characteristics and outcome were compared according to the status of MYD88. The median age of the patients was 79 years, and 59% were female. Skin lesions were located on the leg in 76% of the cases. Thirty-four of 58 patients (59%) harbored the MYD88 L265P mutation. Patients had similar clinical characteristics at presentation regardless of their MYD88 status, except that those harboring the MYD88 mutation were older (P = .006) and had more frequent involvement of the leg (P = .008). Patients harboring the MYD88 mutation had 3- and 5-year-specific survival rates of 65.7% and 60.2% vs 85.4% and 71.7% in patients with the wild-type allele. The MYD88 mutation was significantly associated with shorter disease-specific survival in univariate (P = .03) and multivariate (odds ratio, 3.01; 95% CI, 1.03-8.78; P = .04) analysis. There was no significant difference between the groups in their treatment regimens. Considering overall survival, in univariate (P = .002) and multivariate (odds ratio, 2.94; 95% CI, 1.18-7.30; P = .02) analysis, MYD88 L265P mutation was an independent adverse prognostic factor. This study confirms the high prevalence of MYD88 L265P mutation in PCLBCL-LT and shows its association with shorter survival. The clinical effect of MYD88 mutation activating the nuclear factor-κB pathway supports the use of targeted therapies at the time of relapse after conventional therapies.

REFLECTANCE CONFOCAL MICROSCOPY IN THE DIAGNOSIS OF PRIMARY CUTANEOUS DIFFUSE LARGE B-CELL LYMPHOMAS

The article presents a brief review of the literature about the incidence, classification, clinical manifestations and modern methods for the diagnosis and treatment of the Primary Cutaneous Diffuse Large B-cell Lymphomas. The authors present the clinical case of a preliminary diagnosis of the disease with reflectance confocal microscopy before biopsy and following verification of diagnosis with pathomorphological and immunohistochemical studies of the biopsy specimen. Key words: reflectance confocal microscopy, Primary Cutaneous Diffuse Large B-cell Lymphomas, clinical manifestations, diagnosis, treatment. Cite this article: I.A. Kuklin, M.M. Kokhan, N.V. Kungurov, N.V. Zilberberg, E.P. Topychkanova, N.V. Volkova. Reflectance confocal microscopy in the diagnosis of Primary cutaneous diffuse large B-cell lymphomas . RoJCED 2017;3(4):176-180. https://doi.org/10.26574/rojced.2017.4.3.176

Methotrexate-associated B-cell lymphoproliferative disorders presenting in the skin: A clinicopathologic and immunophenotypical study of 10 cases.

Methotrexate (MTX)-associated B-cell lymphoproliferative disorders (B-LPD) may first present in the skin, but their clinicopathologic features are still ill defined. Differentiation from primary cutaneous follicle center lymphoma and primary cutaneous diffuse large B-cell lymphoma, leg type (PCLBCL-LT) is important, as MTX-associated B-LPD may show spontaneous regression after withdrawal of MTX therapy. In the present study, the clinicopathologic and phenotypical features of 10 patients with MTX-associated B-LPD first presenting in the skin, including 5 EBV(+) and 5 EBV(-) cases, were investigated. Six patients had skin-limited disease. Clinically, abrogation of MTX therapy resulted in a complete response in 4 cases and a partial response in another 2. The 5-year disease-specific survival was 90%. MTX-associated B-LPD differed from primary cutaneous follicle center lymphoma by the presence of ulcerating and/or generalized skin lesions, an infiltrate composed of centroblasts/immunoblasts rather than large centrocytes, reduced staining for CD79a, and expression of BCL2, IRF4, and FOXP1 in most cases. EBV(+) MTX-associated B-LPD differed from PCLBCL-LT by the presence ulcerative skin lesions, marked tumor cell polymorphism, reduced staining for CD79a, and expression of CD30 and EBV. EBV(-) cases showed morphologic and immunophenotypical similarities to PCLBCL-LT but differed by presentation with generalized skin lesions in 4 of 5 cases. The results of this study, showing a relatively good clinical outcome and spontaneous disease regression after only withdrawal of MTX in a considerable proportion of patients, underscores the importance of a careful wait-and-see policy before considering more aggressive therapies in patients with MTX-associated B-LPD of the skin.

A Case of Cutaneous Diffuse Large B-cell Lymphoma.

Received/Gelis tarihi : June 10, 2013 Accepted/Kabul tarihi : September 4, 2013 To the Editor, We report the clinical findings of a 55-year-old woman who presented with purple-reddish nodules on her face diagnosed as primary cutaneous diffuse large B-cell lymphoma (PCLBCL), which is very rarely seen in this area. A 55-year-old woman applied to our oncology department after a brief episode of fever, general weakness, and erythematous patches and plaques in the facial area (Figure 1). Other associated symptoms and signs were general malaise and weight loss of 5 kg in 1 month. She had previously been well. A diagnostic biopsy showed an infiltration of large lymphoid cells staining positively for CD20, BCL-6, BCL-2, and PAX5, suggesting a diagnosis of diffuse large B-cell lymphoma (Figure 2). The cells were negative for CD5 and CD10. Renal and liver functions were normal. Bone marrow aspiration and biopsy showed no evidence of lymphoma. There was no other systemic organ involvement. The patient began receiving systemic chemotherapy with rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone. After 3 cycles of treatment, the large tumor showed no gradual improvement; this was suggestive of a lack of response. Rituximab plus ifosfamide, carboplatin, and etoposide chemotherapy (R-ICE) were therefore initiated. The patient was treated with 3 cycles of R-ICE chemotherapy. The patient declined additional treatment because her condition remained progressive despite the treatment, and she died soon after. Infomed consent was obtained. PCLBCL is a rare primary cutaneous lymphoma characterized by a diffuse proliferation of large B cells consisting of centroblasts and immunoblasts, occurring most commonly on the legs [1]. PCLBCL affects elderly population with a female predominance. This type of lymphomas tend to develop on the lower limbs, predominantly as large dermal nodules or tumors, which are either solitary or multifocal and rapidly enlarging [1]. PCLBCL can also rarely occur at other cutaneous sites [2]. The prognosis of PCLBCL is poor, with a 5-year survival of 41%-58%

Can Cutaneous Low-Grade B-cell Lymphoma Transform Into Primary Cutaneous Diffuse Large B-cell Lymphoma? An Immunohistochemical Study of 82 cases

Low-grade B-cell lymphomas of the skin, especially, primary cutaneous follicle center cell lymphoma has several distinctive features when compared with nodal/systemic follicular lymphomas, as they are frequently negative for bcl-2 and CD10, and only fewer than 25% of the cases show a bcl-2 rearrangement. The risk of transformation of a cutaneous low-grade B-cell lymphoma, such as primary cutaneous follicle center cell lymphoma, to primary cutaneous diffuse large B-cell lymphomas (PCDLBCL) has not been clearly delineated in the literature. Transformation of systemic/nodal follicular lymphoma into aggressive DLBCL is associated with rapid disease progression, refractoriness to treatment, and poor prognosis. The authors studied 82 cases of primary cutaneous DLBCL using antibodies for follicular dendritic cells (FDCs), CD21, and CD35 to detect networks of FDCs that could possibly indicate transformation of preexisting low-grade B-cell lymphoma to PCDLBCL. All cases were classified as PCDLBCL using strict histologic and immunophenotypic criteria. Fifty-three cases were classified as primary cutaneous DLBCL of "leg type," and 29 cases were classified as primary cutaneous DLBCL, "NOS" category. Immunohistochemical studies were performed in all 82 cases; in 15 cases, a CD21/CD35+ network of FDCs was noted within the tumor, indicating the presence of remnants of residual germinal centers, suggesting the possibility of a transformed low-grade B-cell lymphoma. In summary, the authors' findings seem to indicate that some cases of primary cutaneous DLBCL may result from transformation of a low-grade B-cell lymphoma. Further studies are necessary to evaluate the significance of their findings by using ancillary techniques including genetic analysis.

Improvement of Survival in Patients With Primary Cutaneous Diffuse Large B-Cell Lymphoma, Leg Type, in France

Primary cutaneous diffuse large B-cell lymphoma, leg type (PCDLBCL-LT), occurs in elderly patients and has been considered as a lymphoma with a poor prognosis, with estimated 5-year specific survival rates of approximately 50%. The hypothesis of an improvement in prognosis over time has not been studied. To evaluate this hypothesis in a large series of patients and investigate factors associated with prognosis as well as improvement in the prognosis. A retrospective multicenter study was conducted including dermatology departments belonging to the French Study Group on Cutaneous Lymphoma. Participants were 115 patients with PCDLBCL-LT diagnosed between 1988 and 2003 (period 1) or between 2004 and 2010 (period 2). Age, sex, period of diagnosis, number of skin lesions, tumor stage, tumor location (leg vs nonleg), lactate dehydrogenase level, type of therapy (with or without a combination of rituximab and polychemotherapy [PCT]), and outcome were recorded. Baseline characteristics and outcome were compared according to period of diagnosis and type of therapy. Prognosis factors were identified by univariate and multivariate survival analyses. The mean age of the patients was 76.9 years, and 47% of the patients were older than 80 years. The 3- and 5-year specific survival rates improved between period 1 and period 2, from 55% to 74% and from 46% to 66%, respectively (P = .01). Patients had similar baseline characteristics during both periods, but rituximab-PCT regimens were administered to 88.5% of the patients in period 2 vs 16.7% in period 1 (P < .001). The 3- and 5-year specific survival rates were 80% and 74%, respectively, in patients who received a rituximab-PCT regimen compared with 48% and 38% in those who received less-intensive therapies. No significant difference was observed between both groups in age and baseline prognostic factors. In multivariate analysis, treatment without rituximab-PCT was the only adverse prognostic factor (odds ratio, 4.6 [95% CI, 2.4-9.1]; P < .001), whereas the number of skin lesions (P = .06) and location on the leg (P = .07) had only borderline significance. A major improvement in the survival of patients with PCDLBCL-LT has occurred over time in France, mainly as a result of the use of intensive rituximab-PCT regimens in most patients, including very elderly ones. Until further prospective clinical trials are conducted, such regimens should be considered as the standard of care in these patients.

Cutaneous Lymphomas

: Primary cutaneous B-cell lymphomas (PCBCL) are the second most common form of primary cutaneous lymphomas and account for approximately 25%-30% of all primary cutaneous lymphomas. Both forms of low-grade malignant PCBCL, primary cutaneous follicle center lymphoma (PCFCL) and primary cutaneous marginal zone lymphoma of mucosa-associated lymphoid tissue-type (MALT lymphoma) (PCMZL) represent the vast majority of PCBCL and show an indolent slowly progressive course and an excellent prognosis despite a high recurrence rate. Genetic analysis indicates that PCMZL differ from other forms of extranodal MALT lymphomas. The more common class-switched and the non-class-switched form of PCMZL can be distinguished as two distinctive subsets that differ in the cellular composition, IgM expression, and biological behavior with extracutaneous involvement found in the non-class-switched form. Recently, unusual clinical and histological forms of PCMZL and PCFCL manifesting with miliary or agminated lesions have been described that are diagnostically challenging. In contrast to PCMZL and PCFCL, primary cutaneous diffuse large B-cell lymphoma, leg type, and other rare forms of large B-cell lymphomas such as intravascular large B-cell lymphoma have an unfavorable prognosis. There is an emerging group of Epstein-Barr virus (EBV)-driven B-cell lymphoproliferations including posttransplant lymphoproliferative disorders and mucocutaneous ulcer occurring in immunocompromised patients and EBV-associated diffuse large B-cell lymphoma of the elderly arising in the setting of senescence-linked immunodeficiency. This review reports on recent findings expanding the spectrum of clinicopathological features, differential diagnostic aspects, and the pathogenesis of PCBCL and discusses the group of EBV-associated B-cell lymphoproliferations involving the skin.

Primary Cutaneous Diffuse Large B-Cell Lymphoma with Tongue Involvement

We report a case of diffuse large B-cell lymphoma involving the thigh skin and tongue in an 85-year-old woman. No systemic symptoms or other lesions were observed at diagnosis. Local radiotherapy was effective, but cutaneous recurrence occurred 6 months after the treatment. The patient died of old age with no macroscopically distinguishable nodal or systemic lesions. A postmortem examination revealed intravascular invasion into the tongue, lung, and lymph nodes around the pancreas. To our knowledge, this is the first report of primary cutaneous diffuse large B-cell lymphoma with tongue involvement.

Primary Cutaneous Diffuse Large B-Cell Lymphoma of the Leg: Apropos of a Fatal Case

Primary cutaneous lymphomas are a heterogeneous group of lymphoproliferative disorders with skin involvement and no evidence of systemic disease at the time of diagnosis. Since the 1980s, primary cutaneous B-cell lymphomas have been considered a specific group of lymphomas. Large B-cell lymphoma of the leg accounts for 2% of primary cutaneous lymphomas, but its classification has been under debate over the past few years. It was recognized as an independent entity in the 2004 WHO-EORTC classification of cutaneous lymphomas. It is clinically characterized by erythematous nodules or tumors, frequently unilateral, on the distal third of the lower limbs in patients of advanced age. The clinical behavior is generally indolent, and cases of extracutaneous spread are infrequent but have an intermediate prognosis. We report the case of an 85-yr-old man who presented with a six-week history of asymptomatic indurated erythematous plaque on the left leg that had rapidly and progressively increased in size. Histological analysis revealed a CD20- and bcl-2-positive large cell lymphoid infiltrate throughout the dermis. The extension study was normal. Chemotherapy was started with the R-CHOPregimen, and the patient evidenced a good clinical response but died after two months.

MicroRNA Profiling of Primary Cutaneous Large B-Cell Lymphomas

Aberrant expression of microRNAs is widely accepted to be pathogenetically involved in nodal diffuse large B-cell lymphomas (DLBCLs). However, the microRNAs profiles of primary cutaneous large B-cell lymphomas (PCLBCLs) are not yet described. Its two main subtypes, i.e., primary cutaneous diffuse large B-cell lymphoma, leg type (PCLBCL-LT) and primary cutaneous follicle center lymphoma (PCFCL) are characterized by an activated B-cell (ABC)-genotype and a germinal center B-cell (GCB)-genotype, respectively. We performed high-throughput sequencing analysis on frozen tumor biopsies from 19 cases of PCFCL and PCLBCL-LT to establish microRNA profiles. Cluster analysis of the complete microRNome could not distinguish between the two subtypes, but 16 single microRNAs were found to be differentially expressed. Single microRNA RT-qPCR was conducted on formalin-fixed paraffin-embedded tumor biopsies of 20 additional cases, confirming higher expression of miR-9-5p, miR-31-5p, miR-129-2-3p and miR-214-3p in PCFCL as compared to PCLBCL-LT. MicroRNAs previously described to be higher expressed in ABC-type as compared to GCB-type nodal DLBCL were not differentially expressed between PCFCL and PCLBCL-LT. In conclusion, PCFCL and PCLBCL-LT differ in their microRNA profiles. In contrast to their gene expression profile, they only show slight resemblance with the microRNA profiles found in GCB- and ABC-type nodal DLBCL.