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+/TCRβF1+. 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.     

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.     

The applicability and prognostic value of the new TNM classification system for primary cutaneous lymphomas other than mycosis fungoides and Sézary syndrome: results on a large cohort of primary cutaneous B-cell lymphomas and comparison with the system used by the Dutch Cutaneous Lymphoma Group

BACKGROUND: Recently, a consensus proposal was published for a TNM classification system for all primary cutaneous lymphomas other than mycosis fungoides and Sézary syndrome, meant to document extent of disease in a consistent manner. The applicability and the prognostic significance of this system have not been investigated thus far. OBJECTIVES: To test the applicability and prognostic relevance of the proposed TNM classification system on a cohort of primary cutaneous B-cell lymphomas (CBCL). METHODS: The study group included 71 primary cutaneous marginal zone lymphomas (PCMZL), 171 primary cutaneous follicle centre lymphomas (PCFCL) and 58 primary cutaneous diffuse large B-cell lymphomas, leg type (PCLBCL, LT). As only patients with primary cutaneous lymphoma were included (T1-3, N0M0), only the T-rating was scored. The results were compared with the scoring as applied by the Dutch Cutaneous Lymphoma Group. RESULTS: The system was easily applicable to all cases. In PCMZL and PCFCL no correlation was found between T-score and survival (5-year disease-specific survival: T1, 100% and 98%; T2, 94% and 93%; T3, 100% and 88%, respectively). In PCLBCL, LT there was a clear, although statistically not significant, association between increasing T-score and reduced survival (5-year disease-specific survival: T1, 75%; T2, 49%; T3, 0%; P = 0.077). Comparing the TNM system with the Dutch Cutaneous Lymphoma Group system, there was a discrepancy in the classification of 20 cases. CONCLUSIONS: The new TNM system is a useful tool to document disease extent in patients with CBCL and provides prognostic information in the group of patients with PCLBCL, LT.     

p53 and bcl-2 expression do not correlate with prognosis in primary cutaneous large T-cell lymphomas

Overexpression of p53 protein in cutaneous T-cell lymphoma (CTCL) has been reported in primary cutaneous large T-cell lymphomas (PCLTCL) and has been associated with tumor progression and transformation in mycosis fungoides. However, the prognostic significance of p53 expression has not been studied thus far. In the present study we investigated the expression of p53 as well as bcl-2 protein in 27 PCLTCL, including 19 CD30-positive and 8 CD30-negative lymphomas, retrieved from the registry of the Dutch Cutaneous Lymphoma Working Group.
The results were correlated with follow-up data and proliferative activity, as assessed by the percentage of MIB-1 positive tumor cells.
Overexpression of p53 protein, defined as nuclear staining of more than 5% of the tumor cells, was found in 10 of 27 cases (37%), including 6 of 19 (32%) CD30+lymphomas and 4 of 8 (50%) CD30–PCLTCL. bcl-2 protein was expressed in 6 of 19 (32%) CD30+lymphomas and in only 1 of 8 (12%) CD30–PCLTCL. However, no significant correlation between p53 or bcl-2 expression and prognosis was found, neither in the whole group, nor within the CD30+ or CD30– group. In addition, no relationship between p53 expression and proliferative activity was found. The results confirm that p53 expression is more common in PCLTCL than in mycosis fungoides and Sézary syndrome. However, neither p53 nor bcl-2 expression correlated with survival or proliferative activity.     

Primary cutaneous diffuse large B-cell lymphoma, leg type: clinicopathologic features and prognostic analysis in 60 cases

OBJECTIVES: To describe clinicopathologic features and to identify prognostic factors in a large series of primary cutaneous diffuse large B-cell lymphoma, leg type (PCLBCL LT), as defined in the recent World Health Organization-European Organization for Research and Treatment of Cancer classification of cutaneous lymphomas. DESIGN: Retrospective multicenter study from the French Study Group on Cutaneous Lymphomas. SETTING: Nineteen departments of dermatology in 10 regions of France. PATIENTS: Sixty patients with a PCLBCL LT included in the registry of the French Study Group on Cutaneous Lymphomas. MAIN OUTCOME MEASURES: Age, sex, outcome, therapy, B symptoms, cutaneous extent, number of lesions, location (leg vs nonleg), serum lactate dehydrogenase level, and MUM-1 and Bcl-2 expression were recorded. Disease-specific survival was used as the main end point. Prognostic factors were identified using a Cox proportional hazards model. RESULTS: Primary cutaneous diffuse large B-cell lymphoma, leg type is characterized by a predilection for the leg (72%), a high proportion of Bcl-2 expression (85%), an advanced age at onset (mean age, 76 years), and frequent relapses and extracutaneous dissemination. The overall 5-year disease-specific survival rate was 41%. Location on the leg and multiple skin lesions were predictive of death in multivariate analysis. Although no variable related to therapy was significantly associated with survival, patients recently treated with combinations of anthracycline-containing chemotherapies and rituximab had a more favorable short-term outcome. CONCLUSIONS: Primary cutaneous diffuse large B-cell lymphoma, leg type is a distinct entity with a poor prognosis, particularly in patients with multiple tumors on the legs. Despite the advanced age of many patients, the prognosis could be improved with combinations of anthracycline-containing chemotherapies and rituximab.     

The skin-associated lymphoid tissue-related B-cell lymphomas

Primary cutaneous B-cell lymphomas (CBCLs) should be clearly separated from non-Hodgkin's B-cell lymphomas with secondary cutaneous involvement and from cutaneous B-cell pseudolymphomas. The majority of CBCLs are characterized by a homogeneous clinical presentation and behavior, with good response to local radiotherapy, low tendency to extracutaneous spread, and excellent prognosis. According to the European Organization for Research on the Treatment of Cancer classification of primary cutaneous lymphomas, CBCLs with an indolent behavior are divided into 2 subgroups: follicular center cell lymphoma and immunocytoma/marginal zone lymphoma, due to putative histologic similarities with their purported nodal counterparts. In addition, a third subgroup with intermediate prognosis (large B-cell lymphoma of the leg) is identified. Conversely, the identification of distinct subgroups is disputable from a strictly histologic, immunophenotypic, and genotypic point of view, and has neither correlation with the clinical course nor the prognosis of the disease. Moreover, the majority of CBCLs show a uniform immunophenotype (CD5-, CD10-) and genotype (lack of bcl-1/bcl-2 and c-myc gene rearrangement) of neoplastic cells. Therefore, we favor the use of the term Skin-Associated Lymphoid Tissue (SALT)-related B-cell lymphomas, due to the close similarities between CBCLs and mucosa-associated lymphoid tissue (MALT) lymphomas, and the evidence for an acquired B-cell arm of SALT.     

Linfoma cutáneo primario difuso de células grandes-tipo pierna con regresión espontánea

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.     

Comparative genomic hybridization analysis of cutaneous large B-cell lymphomas

The aim of the present study was to identify genetic aberrations in a series of patients with cutaneous large B-cell lymphoma (LBCL) using comparative genomic hybridization (CGH). Eighteen consecutive patients with primary (13 patients) (PCLBCL) and secondary (five patients) (SCLBCL) cutaneous large B-cell lymphoma were included in the study. Nine cases corresponded to PCLBCL leg type and four cases primary cutaneous follicle centre-cell lymphoma (PCFCL). Chromosomal imbalances (CIs) were detected in 14 of 18 samples (77.8%). All of nine cases with PCLBCL leg type and two of four cases with PCFCL showed CIs (100% and 50%, respectively). Regarding SCLBCL, in three of five cases (60%), CIs were detected. The most frequently detected gains involved 2q, 5q, 3 and 7q and amplifications affected 18, 12 and 13. Frequent losses were found in 17p. In PCLBCL leg type, the most frequent gains involved 2q and 7q, amplifications were localized in chromosomes 12, 13 and 18 and losses affected chromosomes 17p and 19. In PCFCL, gains located in 3q, 4 and 7q were found. Our study seems to confirm clear-cut differences between primary cutaneous LBCL and nodal diffuse LBCL, and it suggests the presence of genotypic differences between cases of PCLBCL leg type and cases of PCFCL.     

Simultaneous aberrations of single CDKN2A network components and a high Rb phosphorylation status can differentiate subgroups of primary cutaneous B-cell lymphomas

The cyclin-dependent kinase inhibitor 2A (CDKN2A) gene on chromosome 9p21 encodes p16 (INK4A), the inhibitor of the CDK4/retinoblastoma (Rb) cell proliferation pathway, as well as p14 (ARF), which controls p53-dependent pathways. Inactivation of p16 has previously been associated with the prognostically unfavourable primary cutaneous diffuse large B-cell lymphoma, leg type (PCLBCL, LT). In this work, we analysed 22 tumors [nine primary cutaneous follicle centre lymphomas (PCFCL), seven primary cutaneous marginal zone lymphomas (PCMZL) and six PCLBCL, LT] not only for alterations of the p16 gene but also for p14, p53 and Rb by fluorescence in situ hybridization (FISH) and immunohistochemistry. In most PCLBCL, LT (4/6) alterations of CDKN2A (two biallelic deletions, one monoallelic deletion and one trisomy 9) and in addition the highest frequency of deletions of p53 (3/6) and Rb (3/6) were detected. p16 was not expressed but very high levels of phosphorylated Rb, indicating a functional effect of genomic CDKN2A alterations on the protein level in PCLBCL, LT. Regarding the p14/p53 axis, PCLBCL, LT showed a variable expression. Neither PCFCL nor PCMZL showed alterations of CDKN2A and also deletions of p53 or Rb were extremely rare in these subtypes. Exclusively in PCMZL, p53 protein was consistently lacking. In conclusion, only PCLBCL, LT is characterized by a high frequency of aberrations of the CDKN2A network components in both important tumor suppressor pathways regulated by the CDKN2A gene. Moreover, PCLBCL, LT appears to be distinguishable from PCMZL not only by its level of p53 expression but also by its stage of Rb phosphorylation. The latter may also apply to a subgroup of PCFCL.     

大疱性类天疱疮并发原发性皮肤弥漫性大B细胞淋巴瘤

报告1例大疱性类天疱疮并发原发性皮肤弥漫性大B细胞淋巴瘤.患者男,80岁.全身水肿性红斑伴水疱、大疱,诊断为大疱性类天疱疮.在发病7个月后,右胫前出现多个暗紫红色结节,逐渐增多、增大,并扩展至右股内侧和背部.皮损组织病理检查示真皮全层及皮下脂肪小叶弥漫致密的淋巴细胞浸润,可见多数淋巴细胞体积增大,形态不规则,核大深染,可见核分裂相.免疫组化染色:CD20( ),bcl-2( ),bcl-6( ).诊断:原发性皮肤弥漫性大B细胞淋巴瘤.在肿瘤出现后1个月,患者大疱性类天疱疮的病情出现反复,通过CHOP方案治疗,病情明显好转.     

The histomorphologic spectrum of primary cutaneous diffuse large B-cell lymphoma: a study of 79 cases

Primary cutaneous large B-cell lymphomas (PCLBCL) have historically been a matter of debate in the literature. The 2005 World Health Organization-European Organization for Research and Treatment of Cancer (WHO-EORTC) classification scheme segregated cutaneous B-cell lymphomas into 3 groups: primary cutaneous marginal zone B-cell lymphoma, primary cutaneous follicle center cell lymphoma, and primary cutaneous diffuse large B-cell lymphoma (PCDLBCL), "leg type" (PCDLBCL-LT). Additionally, the WHO-EORTC classification scheme utilized the term PCLBCL "other" not otherwise specified (NOS) type for rare cases of PCLBCL not belonging to either the "leg type" or the primary cutaneous follicle center cell lymphoma group. In this study, we retrospectively assessed the histomorphologic features of 79 cases of PCDLBCLs, including those of "leg type" and "other" NOS type, to further categorize the histologic spectrum of these unusual cutaneous neoplasms. The histologic diagnosis of PCLBCL usually poses little diagnostic difficulty; however, some cases may adopt unusual or unfamiliar appearances mimicking other lymphoproliferative disorders or other malignant neoplasms. Seventy-nine cases, occurring in 37 men and 42 women, aged 34-94 years, were analyzed. Fifty-three cases were classified as "leg type" and 26 cases were classified as "other" NOS type using the WHO-EORTC classification. Of the 53 cases classified as "leg type," 33 were women and 20 were men; of the 26 cases of "other" NOS type, 9 were women and 17 were men. In the "leg type" category, 31 cases were located on the lower extremities, 5 cases on the face, 5 cases on the arm, 3 cases on the chest, 2 cases on the shoulder, 2 cases on the back, 1 case on the trunk, 1 case on the buttock, 1 case on the supraclavicular area, 1 case on the head, and 1 case on the flank. Of the "other" NOS type category, 8 cases were located on the face, 5 cases on the shoulder, 3 cases on the head, 2 cases on the abdomen, 2 cases on the chest, 1 case on the trunk, 1 on the vulva, 1 on the axilla, 1 on the back, 1 on the neck, and 1 on the hip. Most cases assessed showed the classic morphologic appearance of PCDLBCL, but cases mimicking Burkitt lymphoma (starry-sky pattern), natural killer-cell (NK) lymphoma, mycosis fungoides (epidermotropism), low-grade B-cell lymphomas, epithelial malignancies, and Merkel cell carcinoma were encountered in this series. The high frequency of these rare histologic patterns can be explained by a bias associated with consultation practice. Careful histologic examination and immunohistochemical stains were used to establish the correct diagnosis. The differential diagnosis of PCDLBCL is broad and difficult to define histologically. Knowledge of these rare histologic variants is necessary to avoid misinterpretation of these cases as nonlymphoid malignancies.     

Bcl-2, Bcl-6 and CD10 expression in cutaneous B-cell lymphoma: further support for a follicle centre cell origin and differential diagnostic significance

BACKGROUND: Primary cutaneous follicle centre cell lymphomas (PCFCCLs) are the most common type of cutaneous B-cell lymphoma. There is ongoing discussion on the origin of the neoplastic B cells in these PCFCCLs, and consequently on their relation to the groups of primary cutaneous marginal zone B-cell lymphomas (PCMZLs) and nodal follicular lymphomas. OBJECTIVES: To define better the neoplastic B cells in PCFCCLs, and to find out if differences in the expression of the antiapoptopic protein Bcl-2, and Bcl-6 and CD10, molecules which are normally expressed by the neoplastic B cells in nodal follicular lymphomas, might have diagnostic or prognostic significance in cutaneous B-cell lymphoproliferative disorders. METHODS: Pretreatment biopsies of well-defined groups of PCFCCL (n = 24), PCMZL (n = 14), primary cutaneous large B-cell lymphoma of the leg (PCLBCL-leg; n = 19), secondary cutaneous follicular lymphoma (n = 3) and cutaneous pseudo-B-cell lymphoma (n = 6) were investigated by immunohistochemistry for expression of Bcl-2, Bcl-6 and CD10. RESULTS: The PCFCCLs consistently expressed Bcl-6, whereas CD10 and Bcl-2 were expressed in only one and two of 24 cases, respectively. In contrast, PCMZLs were always negative for Bcl-6 and CD10, but were Bcl-2 positive, whereas skin and lymph node localizations of secondary cutaneous follicular lymphomas consistently expressed all of Bcl-2, Bcl-6 and CD10. Reactive follicle centre cells in pseudo-B-cell lymphomas expressed Bcl-6 (six of six cases) and CD10 (five of six cases), but not Bcl-2. PCLBCL-leg was Bcl-6 positive and CD10 negative in all cases, irrespective of clinical outcome, and strongly expressed Bcl-2 protein in all but two cases. CONCLUSIONS: The results of the present study provide further support for the follicle centre cell origin of both PCFCCL and PCLBCL-leg, and indicate that staining for Bcl-2, Bcl-6 and CD10 can serve as an important adjunct in the differential diagnosis of cutaneous B-cell lymphoproliferative disorders.     

Primary cutaneous B-cell lymphoma leg type: good response with the RADHAP 21 protocol

Primary cutaneous lymphomas are defined as the ones that exclusively affect the skin for up to 6 months after the diagnosis. B-cell lymphomas represent 20-25% of primary cutaneous lymphomas and have, among its subtypes, the leg type, which represents 10 to 20% of cutaneous B-cell lymphomas, generally affecting elderly people and with an intermediate prognosis. This is the report of a rare case of a leg-type B-cell lymphoma with an exuberant clinical presentation affecting a young male patient.     

Characteristics of cutaneous lymphomas in Osaka, Japan (1988-1999) based on the European Organization for Research and Treatment of Cancer classification

Based on accumulating information, European investigators proposed a new classification for primary cutaneous lymphomas known as the European Organization for Research and Treatment of Cancer (EORTC) classification. The clinical utility of this classification in Japanese cases has not been evaluated. Material from 65 patients with cutaneous lymphomas (48 with primary disease and 17 with secondary disease) who were admitted to Osaka University Hospital during the period 1988 through 1999 was reviewed. Immunohistochemical analysis was performed in all cases. Cutaneous T-cell lymphoma (CTCL) comprised mycosis fungoides (15 cases), Sézary syndrome (1 case), lymphomatoid papulosis (5 cases), large cell CTCL (13 cases), pleomorphic small- or medium-sized CTCL (2 cases), and cutaneous natural killer /T-cell lymphoma (4 cases). B-cell lymphomas comprised 7 cases of follicle center cell lymphoma and 1 case of diffuse large B-cell lymphoma of the leg. Each category of disease in the EORTC scheme showed its characteristic features in our series. Five of 13 large cell CTCL cases were positive for CD30, and 5 were negative. The 5-year survival rate of patients with large cell CTCL CD30+ disease was 100% and that of patients with CD30- disease was 0%. (p > 0.1). Only 1 of 7 CTCL cases expressing CD30 was ALK-1+, and all 7 cases showed a favorable clinical course. The EORTC classification is effective in dealing with Japanese cases of cutaneous lymphomas.     

Primary cutaneous large B-cell lymphomas

According to the European Organization for Research and Treatment of Cancer classification, primary cutaneous large B-cell lymphomas are subdivided into 2 groups: follicle center cell large B-cell lymphomas and large B-cell lymphomas of the leg. The first type predominantly affects middle-aged adults with an equal gender distribution and presents with lesions on the head and trunk. Histology shows proliferations of predominantly large cleaved cells. The prognosis is excellent, with a 5-year survival rate >90%. The second group predominantly affects elderly females. Histologically the lesions are composed of centroblasts and/or immunoblasts (large round cells). The prognosis is more unfavorable with a 5-year survival rate of 50%. Intravascular large B-cell lymphoma is still classified as a provisional entity.     

Systemic therapy with cyclophosphamide and anti-CD20 antibody (rituximab) in relapsed primary cutaneous B-cell lymphoma: a report of 7 cases

BACKGROUND: Rituximab, a chimeric antibody directed against CD20, has a high therapeutic value in refractory/relapsed low-grade or follicular B-cell non-Hodgkin's lymphomas as a monotherapy or in combination with polychemotherapy. OBJECTIVES: We sought to evaluate the clinical activity and toxicity of a schedule foreseeing the use of intravenous rituximab preceded by single-dose cyclophosphamide in the treatment of patients with primary cutaneous B-cell lymphoma who progressed and relapsed after chemotherapy. METHODS: A total of 7 patients were treated; 4 had both cutaneous lesions and nodal or visceral involvement. All the patients had been previously treated with at least 1 standard chemotherapy regimen, and 4 with 2 or more, with a median response duration of 8 months. Immunohistochemistry on frozen sections was performed with monoclonal antibodies directed against CD20, CD55, and CD59 before rituximab treatment. RESULTS: The overall objective response rate was 85.7%, with a complete response in 5 patients; treatment was well tolerated in all cases. After a median follow-up of 13 months, 2 patients showed a cutaneous relapse. The response durations of the remaining patients who were disease-free are now 5, 7, 17, and 18 months. No relationship was found between CD55 and CD59 expression and the clinical outcome. CONCLUSION: Although a longer follow-up period is needed to confirm these data, our results are encouraging, particularly in terms of disease-free survival.     

Primary cutaneous B-cell lymphoma: a clinical, histological, phenotypic and genotypic study of 21 cases

The clinical, histological, phenotypic and genotypic features of 21 primary cutaneous B-cell lymphomas (CBCLs) have been investigated. The patients were 13 men and eight women aged 34-91 years (median 67) at diagnosis. Eighteen patients had localized disease, and three had multiple skin lesions at diagnosis. Twelve patients developed cutaneous or extracutaneous recurrences, and five died from malignant lymphoma 7-84 months (median 36) after diagnosis. Histological examination showed features of marginal zone/mucosa-associated lymphoid tissue (MALT)-type lymphoma in 12 cases. Three of these had transformed to diffuse large B-cell lymphoma (DLBCL) in relapse biopsies. The remaining cases were seven primary DLBCLs and two cases tentatively classified as follicle centre cell (FCC) lymphoma. The neoplastic B cells showed similar phenotypes and genotypes in most cases (CD20+, CD79+, CD5-, CD10-, cyclin D1-, bcl-2+, bcl-x-, bax-, t(14;18)-negative). p53 protein was expressed in five cases, and four harboured mis-sense or loss-of-function mutations in the p53 gene. Deletion or promoter region hypermethylation of the p16INK4a gene was detected in two patients with DLBCL. The level of retinoblastoma protein expression and the proliferative fraction were significantly higher in DLBCL (> 50%) than in MALT- or FCC-type lymphomas (< 10%). Features associated with an unfavourable prognosis were the presence of multiple skin lesions at diagnosis, transformation from MALT-type lymphoma to DLBCL, and possibly p16INK4a aberrations. It is concluded that most CBCLs are dissimilar from FCC lymphomas and seem to be more closely related to marginal zone/MALT-type lymphomas. It is also suggested that there are fundamental differences between DLBCL and other histological categories of CBCL, indicating that cutaneous DLBCL is a separate entity with an increased growth potential and genetic features similar to DLBCL originating in other anatomical sites.     

Treatment of primary cutaneous follicular centre lymphoma with rituximab: a report of two cases

Rituximab (anti-CD20 chimeric monoclonal antibody) has been demonstrated to have significant activity in nodal B-cell lymphomas, with very few associated adverse effects. Although primary cutaneous B-cell lymphomas (PCBCL) also express the CD20 antigen, relatively few reports of rituximab use in PCBCL have been published to date. We present two cases of primary cutaneous follicular centre lymphoma treated with rituximab (375 mg/m(2)/week intravenously for 4 weeks). Both cases responded to rituximab, with one partial response and one complete response seen. No adverse effects were observed. To date, disease progression has occurred in one case during overall follow up at 6 and 17 months. The potential role of rituximab in the treatment of these lymphomas is discussed.     

Expression of the T-cell regulatory marker FOXP3 in primary cutaneous large B-cell lymphoma tumour cells

Background Primary cutaneous B‐cell lymphomas (PCBCL) are subdivided into the aggressive form, primary cutaneous diffuse large B‐cell lymphoma, leg type (PCLBCL, LT) and two subtypes of indolent behaviour (primary cutaneous follicle centre lymphoma and primary cutaneous marginal zone B‐cell lymphoma). The difference in clinical behaviour can be explained by the tumour cell itself, or the lymphoma microenvironment including the antitumour immune response. Objectives To investigate the presence of regulatory T cells (Treg), CD4+CD25+FOXP3+, in the microenvironment of PCBCL in correlation with clinical outcome. Methods Tumour specimens of 55 consecutive cases of PCBCL were blinded and analysed for FOXP3, CD4 and CD25 expression by immunohistochemistry. Confocal images were taken with a Leica SP5. Statistical analyses were performed to determine significance. The test was considered significant when P < 0·05. Results The CD4 and FOXP3 expression as well as the CD4/FOXP3 ratio were significantly increased in PCBCL of indolent behaviour in contrast to PCLBCL, LT (P = 0·0002 for CD4, P < 0·0001 for FOXP3 and P = 0·0345 for FOXP3/CD4 ratio). CD25 expression did not differ in the three groups (P = 0·9414). Within the group of patients with PCLBCL, LT we identified a subgroup with FOXP3+ tumour cells as demonstrated by CD20/FOXP3 double stainings. Patients with FOXP3+ PCLBCL, LT tumour cells showed a better prognosis on Kaplan–Meier analysis. Conclusion High numbers of Treg in the lymphoma microenvironment correlate with a better prognosis in PCBCL. In PCLBCL, LT the presence of FOXP3+ tumour cells is beneficial for prognosis suggesting that FOXP3 expression of PCLBCL, LT tumour cells might serve as a tumour suppressor.     

Cutaneous lymphomas other than mycosis fungoides in Singapore: a clinicopathological analysis using recent classification systems

BACKGROUND: Cutaneous lymphomas other than mycosis fungoides (MF) are a heterogeneous group with wide variations in clinical presentation, biological behaviour and prognosis. New classification systems have been designed or proposed in recent years, with well-defined disease entities and emphasis on the importance of site. OBJECTIVES: This study aims to analyse a series of non-MF lymphomas in an institution-based dermatological setting in Singapore, based on the European Organization for Research and Treatment of Cancer (EORTC) classification and the World Health Organization (WHO) classification. A secondary objective is to highlight the clinical utility of both classification systems. PATIENTS AND METHODS: Forty cases diagnosed over a 12-year period were examined by immunohistochemistry with antibodies targeting CD3, CD4, CD5, CD8, CD20, CD30, CD43, CD45RO, CD56 and CD68 in paraffin-embedded specimens. The immunohistological diagnosis was correlated with the clinical presentation and staging investigations for the final diagnosis and the course of disease recorded. RESULTS: Non-MF T-cell lymphomas presenting in the skin comprised 31 cases (78%) and were 3(1/2) times more common than B-cell lymphomas, which comprised nine cases (22%). The common subtypes were lymphomatoid papulosis, CD30+ large cell cutaneous T-cell lymphoma and subcutaneous panniculitis-like T-cell lymphoma. The commonly ascribed B-cell pattern with infiltrates in the mid and deep dermis and perivascular spaces was seen in 60% of T-cell lymphomas. Overall, there were equal numbers of primary cutaneous T-cell lymphomas and those due to concurrent or secondary cutaneous lymphoma. Five of six cases of subcutaneous panniculitis-like T-cell lymphoma had concurrent cutaneous and systemic involvement and their median survival was 7 months. CONCLUSIONS: The predominance of cutaneous T-cell lymphomas in this case series closely matched that reported from east Asia; cutaneous B-cell lymphomas are much less common than in Europe. The EORTC classification, which is designed only for primary cutaneous lymphomas, should be used in conjunction with the WHO classification because of the high prevalence of cutaneous lymphomas as the secondary site of disease from systemic lymphoma. In addition, subcutaneous panniculitis-like T-cell lymphoma is a primary cutaneous lymphoma where systemic involvement is common at initial presentation. We propose full immunophenotyping and complete clinical evaluation with staging investigations for all patients presenting with cutaneous lymphomas other than MF.