Primary cutaneous B-cell lymphoma: classification and treatment

Identifying and addressing unmet clinical needs in primary cutaneous B-cell lymphoma: A consensus-based paper from an ad-hoc international panel

Primary cutaneous B-cell lymphomas (PCBCLs) are lymphoproliferative disorders that appear on the skin without evidence of extracutaneous manifestations at the time of diagnosis. There is a lack of evidence-based guidelines for their clinical management due to the availability of very few large scale studies and controlled clinical trials. Here we present and discuss a series of major unmet clinical needs (UCNs) in the management of PCBCLs by a panel of 16 experts involved in research and clinical practice of PCBCL. The Panel produced recommendations on the appropriateness of the clinical decisions concerning the identified clinical needs and proposed research for improving the knowledge needed to solve them. Recommendations and proposals were achieved by multiple-step formalized procedures to reach a consensus after a comprehensive analysis of the scientific literature. Recommendations and proposals lay in the domain of classification uncertainties of PCBCL, optimization of diagnosis, optimization of prognosis, optimization of staging and critical issues on therapeutic strategies with particular focus on new treatments. These recommendations are intended for use not only by experts but above all by dermatologists and hematologists with limited experience in the field of PCBCLs as well as general practitioners.

Neoplastic and Autoimmune Comorbidities in Patients with Primary Cutaneous B-Cell Lymphoma

Primary cutaneous B-cell lymphomas (PCBCLs) constitute a rare subset of non-Hodgkin lymphoma (NHL), with distinctive clinical and biological characteristics. The risk of autoimmune or neoplastic comorbidities in subjects with NHL has been extensively reported in the literature, but the data available are not directly applicable to PCBCLs. The aim of our study was to determine the frequency of relevant medical conditions, with a primary focus on autoimmune and neoplastic disorders, in subjects with PCBCL. We performed a retrospective observational study involving 56 patients diagnosed histologically with PCBCL and 54 sex- and age-matched controls. Our results show a statistically significant association for neoplastic comorbidities in general (41.1% vs. 22.2%, p = 0.034) and hematological malignancies specifically (19.6% vs. 1.9%, p = 0.0041) with PCBCL compared to controls. We did not highlight a statistically significant difference in the frequency of autoimmune comorbidities (21.4% vs. 9.3%, p = 0.1128) and of chronic viral hepatitis (7.1% vs. 0, p = 0.1184). Finally, type 2 diabetes (19.6% vs. 1.9%, p = 0.0041) was significantly associated with PCBCL. Our preliminary data supporting the association between PCBCLs and neoplastic disorders suggest that altered immune surveillance may be a common predisposing mechanism.

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.

The Safety of Radiotherapy in the Treatment of Primary Cutaneous B-Cell Lymphoma: A Multidisciplinary Systematic Review

Primary cutaneous B-cell lymphomas (PCBCL) are rare types of extranodal non-Hodgkin's lymphoma. The choice of treatment usually depends on the variant of PCBCL, number, size, and location of the lesions, involved body surface area as well as patient's age and health condition. The efficacy of radiotherapy (RT) in the treatment of PCBCL has been widely reported conversely, data about the acute and late skin toxicity, patient's treatment satisfaction and quality of life are scarce. A systematic search using PubMed, Scopus, and Cochrane library was performed to identify full original articles analyzing the safety of RT in patients with PCBCL with the primary outcome to assess the acute and late skin toxicity. Secondary outcomes were complete remission, disease free survival, and overall survival. The literature search resulted in 276 articles including eight studies assessing the safety of RT for the treatment of PCBCL. Most patients (median 73%, range 11.9-99.9%) were recorded as having acute skin toxicity of grade 1-2, while acute grade 3-4 toxicity occurred in a median of 8% (range 4-23%) of patients. A median of 20% (range 4-54%) of patients had late skin toxicity of grade 1-2. No late grade 3-4 toxicity was reported. Only one study evaluated patient's satisfaction showing that the 97% of patients were satisfied with radiation therapy. This systematic review confirms the safety of RT in the treatment of PCBCL. Patients with a PCBCL should be managed in highly specialized centers in the context of a multidisciplinary team including dermatologist, hematologist, pathologist, and radiation oncologist.

Epidemiology and Pathology of T- and NK-Cell Lymphomas

PURPOSE

This review will describe and update readers on the recent changes in the 2017 WHO classification regarding peripheral T-cell lymphomas.

RECENT FINDINGS

Signficant advances in molecular studies have resulted in revisions to the classification as well as introduction to provisional entities such as breast implant-associated ALCL and nodal PTCL with T-follicular helper phenotype.

SUMMARY

Major advances in molecular and gene expression profiling has expanded our knowledge of these rare and aggressive diseases.

Primary Cutaneous B-Cell Lymphoma: Management and Patterns of Recurrence at the Multimodality Cutaneous Lymphoma Clinic of The Ohio State University

BACKGROUND

The increasing incidence of primary cutaneous B-cell lymphomas (PCBCLs) presents new challenges for clinicians. Despite advances in the clinical and pathologic characterization of PCBCL, the significance of the current staging approach as a risk profiling tool and the effect of various treatments on outcome remain unclear.

MATERIALS AND METHODS

We retrospectively reviewed patients who presented with a diagnosis of PCBCL seen at The Ohio State University between 1998 and 2012. We reviewed the initial presentation and treatment modality. We then assessed whether the treatment modality (conservative skin-directed vs. definitive radiation with or without systemic therapy), stage (T1 or ≥T2), or histologic subtype (primary cutaneous follicle center lymphoma [PCFCL] vs. primary cutaneous marginal zone B-cell lymphoma [PCMZL]) affected the risk of recurrence.

RESULTS

We identified 67 patients referred with an initial diagnosis of PCBCL. After imaging, 12 did not meet the criteria for PCBCL and were classified as having systemic B-cell lymphoma with cutaneous involvement. The remaining 55 patients included 25 with PCMZL, 24 with PCFCL, 2 with primary cutaneous large B-cell lymphoma leg type, and 4 with unclassifiable disease. According to the International Society of Cutaneous Lymphoma-European Organization for Research and Treatment of Cancer staging, 30 cases were T1 (55%), 14 T2 (25%), and 11 T3 (20%). Comparing the time to first recurrence (TFR) by indolent PCBCL subtypes, we found no difference in the recurrence risk for either stage (T1, p = .51 vs. T2/T3, p = .30). Comparing TFR by treatment modality, we found no difference in TFR within T1 patients (p = .34) or T2/T3 patients (p = .44).

CONCLUSION

Our limited analysis highlights the importance of complete staging at diagnosis and suggests that the treatment modality does not affect the risk of recurrence in T1 indolent PCBCL.

Small lymphocytic lymphoma with florid perniosis-like features: a case report

BACKGROUND

Small lymphocytic lymphoma is a relatively rare B-cell non-Hodgkin lymphoma that is considered to be the tissue equivalent of the much more common entity chronic lymphocytic leukemia. Cutaneous manifestations of small lymphocytic lymphoma are infrequent and the literature regarding them sparse. We describe here a case of a patient with a history of small lymphocytic lymphoma who developed perniosis-like features of the digits.

CASE PRESENTATION

An 86-year old male patient with previously diagnosed small lymphocytic lymphoma developed painful erythematous swelling of the periungual area of his fingers and toes. This was associated with a dense dermal infiltration of CD5-positive B-lymphoid cells consistent with his low-grade B-cell lymphoma. Although partially refractory to local radiotherapy, the painful swelling of the fingers and toes resolved fully following systemic therapy with chlorambucil and rituximab.

CONCLUSIONS

This unusual cutaneous manifestation of a lymphoma and the favourable response to systemic therapy may be instructive for the management of other patients who develop similar perniosis-like features.

Paediatric cutaneous lymphomas: a review and comparison with adult counterparts

Primary cutaneous lymphomas (CL) in children is rare. Only a few studies focused specifically on paediatric CL and therefore little is known whether primary CL in children are similar to or different from their adult counterparts with respect to the clinicopathological presentation, behaviour and prognosis. An extensive literature search using PubMed/MEDLINE from January 1995 through July 2014 was undertaken for articles reporting cases of paediatric CL. In addition, we identified 31 children with CL in our institutions. Mycosis fungoides and lymphomatoid papulosis are the two most prevalent lymphoma forms in children. A few entities of cutaneous lymphomas such as cutaneous diffuse large B-cell lymphoma leg type, and Sézary syndrome have not been reported so far in children. Other lymphoma entities such as hydroa vacciniforme-like lymphoma are mostly seen in certain geographic areas (Asia, Central and South America). In the paediatric population, low-malignant indolent forms such as primary cutaneous marginal zone lymphoma and primary cutaneous follicle centre lymphoma are very rare, whereas the more aggressive forms of B-cell lymphomas, precursor lymphoblastic lymphomas, and blastic plasmacytoid dendritic cell neoplasm are the most common forms in children, mostly involving the skin secondarily. Most paediatric lymphomas have similar clinicopathological features and course as their adults counterparts, particularly in the group of cutaneous T-cell lymphomas. The spectrum of cutaneous B-cell lymphomas in children significantly differs from the one in adults. Diagnostic work-up and treatment of paediatric patients with lymphomas are best achieved in close collaboration with paediatric haematopathologists and oncologists.

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.

Durable Regression of Primary Cutaneous B-Cell Lymphoma Following Fever-inducing Mistletoe Treatment: Two Case Reports

BACKGROUND

Mistletoe is a complementary cancer treatment that is widely used, usually in addition to and alongside recommended conventional cancer therapy. However, little is known about its use, effectiveness, and safety in the treatment of cutaneous lymphoma.

CASE REPORT

Two patients with primary cutaneous B-cell lymphoma (pT2bcNxM0 follicle center and pT2ac-NxM0 marginal zone) either declined or postponed recommended conventional treatment and received high-dose, fever-inducing mistletoe treatment; a combination of intratumoral, subcutaneous, and intravenous application was given; and one patient also underwent whole-body hyperthermia. The lymphoma regressed over a period of 12 and 8 months, respectively, and after administration of a cumulative dose of 12.98 g and 4.63 g mistletoe extract, respectively. The patients are in remission to date, 3.5 years after commencement of treatment. Neither patient received conventional cancer treatment during the entire observation period.

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.

Primary Cutaneous B-Cell Lymphoma: Role of Surgery

PURPOSE

To evaluate the role of surgery in patients diagnosed with primary cutaneous B-cell lymphoma (PCBCL) – a rare disease entity. The authors offer a rationale for the use of primary surgical excision in the treatment of isolated cutaneous lymphomas.

METHODS

A literature review examining the use of primary surgical excision in the treatment of PCBCL was conducted. The lymphoma database at the Juravinski Cancer Centre (Hamilton, Ontario) was searched from January 1995 to July 2008, generating a list of 4924 patients. A simulated computer program was subsequently designed to search for all possible PCBCLs. A retrospective chart review was then conducted on the new list of 1325 patients, identifying 25 patients diagnosed with PCBCL.

RESULTS

The mean age of the 25 patients with PCBCL was 59.9 years; nine (36%) were treated with surgery, and sixteen (64%) with radiation. The average follow-up period for patients was 3.6 years. Twenty-four of the 25 patients were completely cured, with only one patient recurring in the radiation subgroup. There were no complications in the surgery subgroup. There were two local complications in the radiation subgroup consisting of chronic ulcerations.

CONCLUSIONS

Primary surgical excision is an effective management option in the treatment of PCBCL, particularly the marginal zone and follicle centre subtypes.

The value of molecular diagnostics in primary cutaneous B-cell lymphomas in the context of clinical findings, histology, and immunohistochemistry

BACKGROUND

Primary cutaneous B-cell lymphoma (PCBCL) is classified into 3 major subtypes: primary cutaneous follicle center lymphoma (PCFCL); primary cutaneous marginal zone B-cell lymphoma (PCMZL); and primary cutaneous diffuse large B-cell lymphoma, leg type (PCLBCL, LT). Diagnosis of PCBCL is mainly based on clinical and (immuno)-histochemical grounds.

OBJECTIVE

We investigated the diagnostic value of the BIOMED-2 Concerted Action BMH4 CT98-3936 protocol in PCBCL.

METHODS

We analyzed with the BIOMED-2 Concerted Action BMH4 CT98-3936 protocol skin specimens from patients with well-defined clinical and (immuno)-histologic PCBCL (n = 18) in comparison with benign lymphocytic infiltrates (n = 9). For molecular staging we also investigated 13 extracutaneous samples from 6 patients with PCLBCL, LT. Each sample was investigated at least twice.

RESULTS

Monoclonality was detected in all of 5 PCFCL; 5 of 6 PCMZL; all of 6 PCLBCL, LT; and 2 of 9 benign lymphocytic infiltrates. In 5 of 6 patients with PCLBCL, LT, a clone corresponding to the clone detected in the skin was detected in 3 of 5 bone-marrow, 4 of 5 blood, and 1 of 3 lymph node specimens. DNA amplification using tubes A and B of IgH was not possible in PCFCL/PCMZL, benign lymphocytic infiltrates, and extracutaneous specimens of PCLBCL, LT, even after repeated analysis up to 11 times. Pseudomonoclonality was identified by repeated analyses in one case of PCMZL and in one case of benign lymphocytic infiltrate.

LIMITATIONS

A multicentric, randomized, blinded study is necessary to confirm our results.

CONCLUSION

Molecular diagnosis supports the clinical and (immuno)-histologic diagnosis in PCBCL. In PCLBCL, LT, molecular staging may be useful. Tubes C through E of IgH and Igκ analyses seem to be superior to tubes A and B of IgH. Each sample should be analyzed at least twice to assess the possibility of pseudomonoclonality.

Primary cutaneous diffuse large B cell lymphoma relapsed solely as a huge lung tumor mimicking a primary pulmonary lymphoma

Primary cutaneous large B cell lymphoma, leg type (PCLBCL-leg) has recently been identified and recognized as a specific entity. Patients with PCLBCL-leg have a higher relapse rate and a poorer prognosis than the other types of primary cutaneous B cell lymphomas, and disease relapse is confined to the skin in the majority of cases with rare exclusive extracutaneous progression. The late occurrence of lymphoma in patients with a prior history of lymphoma may represent a relapse/progression or a distinct tumor unrelated to the original one. The distinction is of important clinical and therapeutic implications. Here, we report the case of a 90-year-old lady with a history of PCLBCL-leg in complete remission after radiotherapy that developed a huge, solitary pulmonary lymphoma without lymphadenopathy 14 months later. The latter was initially considered as stage IE primary pulmonary lymphoma and was treated with combination chemotherapy resulting in complete remission. Retrospective pathologic review and B cell clonality study revealed that the pulmonary tumor was a diffuse large B cell lymphoma of the same clonal origin as the PCLBCL-leg. This case is unique in the exclusive pulmonary relapse and illustrates the importance of expert pathological review and molecular study in the management of lymphoma patients with unusual clinical features.

Low-grade B-cell proliferation progressing to high-grade B-cell lymphoma

We present a case of a primary cutaneous lymphoproliferative process, originally diagnosed as cutaneous lymphoid hyperplasia, which progressed to a nodal high-grade diffuse large B-cell lymphoma 3 years after the initial diagnosis. The 2 processes were related by the presence of the same lymphoid clone in the cutaneous and the nodal proliferation.

Cutaneous non-Hodgkin's lymphoma of the foot: a rare case report

Lymphomas comprise a heterogeneous group of cancers originating in cells of the immune system at different stages of differentiation. Primary cutaneous non-Hodgkin lymphoma of the foot is a rare occurrence. We present a case involving a primary cutaneous marginal zone lymphoma of the foot, and highlight the clinical recognition and treatment of this condition.

LEVEL OF CLINICAL EVIDENCE

4.

Methotrexate-induced primary cutaneous diffuse large B-cell lymphoma with an 'angiocentric' histological morphology

A patient with a 25-year history of rheumatoid arthritis and a 3-year history of methotrexate treatment developed a generalized papular rash. The papules rapidly became necrotic and then resolved, leaving a depressed scar. The rapid course of lesion development and regression was reminiscent of pityriasis lichenoides. Histology revealed a nodular infiltrate composed of a mixture of pleomorphic large B cells positive for CD20, CD30 and CD79a, and of small T cells positive for CD3 and CD4. The T cells had a striking angiocentric distribution, with some of the vessels exhibiting fibrinoid necrosis of the vessel wall reminiscent of lymphomatoid granulomatosis. However, B cells were consistently negative for Epstein-Barr virus (EBV) antigen expression. A thorough examination excluded involvement of organs other than the skin. Thus, this patient was classified as having a rare form of an EBV-negative primary cutaneous T-cell-rich B-cell lymphoma in association with methotrexate treatment.

[Skin tumours of the facial area]

Almost the complete spectrum of skin tumours can occur within the facial area, ranging from benign tumours of infancy to typical malignancies of old age. This spectrum is quiet heterogeneous and comprises every cell type within the skin as a possible origin for tumour growth. Among these are cells derived from the epidermis; adnexal structures; connective, fatty, and vascular tissue; muscle; nerves; melanocytes; and skin-infiltrating inflammatory cells. Due to this diversity, a correct assessment of the clinical findings compared with a histopathologic appraisal in cases of uncertainty is mandatory in order to recommend appropriate therapy. The present overview aims to summarise the basics of the most frequent and most important skin tumours occurring on the face.

Cutaneous lymphoma incidence patterns in the United States: a population-based study of 3884 cases

There have been no prior large population-based studies focusing on cutaneous lymphomas (CL) in the United States. Using the Surveillance, Epidemiology and End Results (SEER) program data, we analyzed age-adjusted CL incidence rates (IRs) and survival rates by sex and race/ethnicity. There were 3884 CLs diagnosed during 2001-2005. Cutaneous T-cell lymphomas (CTCLs) accounted for 71% (age-adjusted incidence rate [IR] = 7.7/1 000 000 person-years), whereas cutaneous B-cell lymphomas(CBCLs) accounted for 29% (IR = 3.1/1 000 000 person-years). Males had a statistically significant higher IR of CL than females (14.0 vs 8.2/1 000 000 person-years, respectively; male-female IR ratio [M/F IRR] = 1.72; P < .001). CL IRs were highest among blacks and non-Hispanic whites (both 11.5/1 000 000 person-years), followed by Hispanic whites (7.9) and Asian/Pacific Islanders (7.1). The CTCL IR was highest among blacks (10.0/1 000 000 person-years), whereas the CBCL IR was highest among non-Hispanic whites (3.5). Over the past 25 years, the CL IR increased from 5.0/1 000 000 person-years during 1980-1982 to 14.3 during 2001-2003. During 2004-2005, the CL IR was 12.7. This recent apparent change could be incomplete case ascertainment or potential leveling off of IRs. CLs rates vary markedly by race and sex, supporting the notion that they represent distinct disease entities.

Bcl-xL gene expression correlated with lower apoptotic cell numbers and shorter progression-free survival in PCFCL

The expression of bcl-x(L), an antiapoptotic member of the bcl-2 family, has been correlated with poor prognosis in nodal follicular lymphomas (NFLs). So far, it has not been studied in primary cutaneous follicle center lymphomas (PCFCLs), which, compared with NFLs, express less frequently t(14;18)(q32;q21) and bcl-2. Using real-time PCR we measured bcl-xL and bcl-2 gene expression levels in laser-microdissected lymphoma cells of 20 PCFCL frozen sections. Numbers of apoptotic cells labeled by TUNEL assay were negatively correlated with bcl-xL expression levels (r=-0.840, P<0.005). Bcl-xL expression was significantly higher in biopsies of patients who developed relapse or disease progression later compared with patients who did not (P=0.022), and higher levels of bcl-xL gene expression were significantly correlated with shorter progression-free survival (PFS) (P=0.017). None of these features was correlated with bcl-2 gene expression levels. Our findings indicate that bcl-xL overexpression is inversely correlated with PFS in PCFCL. Moreover, the inverse correlation between bcl-xL expression levels and apoptotic cell numbers suggests that bcl-xL, through its antiapoptotic effect, might contribute to tumor cell survival in PCFCL.

Primary cutaneous CD4+ small/medium-sized pleomorphic T-cell lymphoma expresses follicular T-cell markers

Cutaneous CD4 small/medium-sized pleomorphic T-cell lymphoma (CSTCL) is a cutaneous T-cell lymphoma defined by a predominance of small-to-medium-sized CD4 pleomorphic T cells, with a favorable clinical course. Cases are also characterized by the presence of a rich infiltrate of reactive B cells. Recently, it has been reported that follicular helper T cells (TFH cells) display a distinct gene expression profile, positive for PD-1, CXCL13, and BCL-6. We report for the first time the expression of PD-1 and other TFH cell markers in CSTCLs and discuss its biologic significance. Sixteen CSTCLs were included in this study, and also 20 reactive inflammatory conditions, 10 primary cutaneous marginal zone, 10 follicular center lymphomas, and 5 primary CD30 cutaneous lymphomas. They were immunohistochemically analyzed for a large panel of markers. Double immunoperoxidase labeling of paraffin sections was performed for PD-1, OCT-2, and BCL-6. Clonal Ig and T-cell receptor rearrangements and Epstein-Barr virus-encoded RNA expression were also evaluated. Morphologic and clinical data were reviewed. Histologic examination showed a dense polymorphic lymphoid infiltrate throughout the dermis. Atypical large CD4 cells were positive for PD-1, CXCL13, and BCL-6 in all cases, and were attached in small clusters, or formed rosettes around CD30/OCT-2+ B blast cells. Epstein-Barr virus was not apparent in any of the cases. A dominant T-cell clone was identified in 14 cases, whereas polymerase chain reaction IgH gene rearrangement studies showed that all cases were polyclonal. None of the patients had lymphadenopathy or showed any evidence of systemic disease, nor did they have any previous history of mycosis fungoides or drug reactions. FTH cell markers are not exclusive to angioimmunoblastic lymphadenopathy but may also be seen in neoplastic cells of CSTCLs. Moreover, these findings suggest that B-cell stimulation by FTH could also take place in some cutaneous T-cell lymphomas.

Indolent primary cutaneous B-cell lymphoma: experience using systemic rituximab

BACKGROUND

Optimal treatment of indolent primary cutaneous B-cell lymphoma (CBCL), marginal zone lymphoma, and follicle center lymphoma, presenting as multiple lesions, has yet to be established. Rituximab is a chimeric monoclonal IgG1 antibody directed against the CD20 antigen of B cells. Clinical efficacy of systemic rituximab in CBCL has yet to be established.

OBJECTIVE

We sought to assess the efficacy of systemic rituximab in the treatment of CBCL.

METHODS

This was a retrospective study of 15 patients with indolent CBCL treated with intravenous rituximab (375 mg/m(2)) as a single agent. Variable maintenance regimen was used in a subset of patients. Responses were categorized as complete response, partial response, stable disease, or progressive disease. The efficacy end points included were objective response rate, time to response, time to progression, and duration of response.

RESULTS

Ten patients with follicle center lymphoma and 5 with marginal zone lymphoma were included. The objective response rate was 87% (60% complete response, 27% partial response). All patients with follicle center lymphoma had a response with 80% achieving complete response. Of the patients with marginal zone lymphoma, 3 had a response, one stable disease, and one progressive disease. Median follow-up was 36 months. Median time to response, duration of response, and time to progression was 30 days, 24 months, and 24 months, respectively.

LIMITATIONS

The study was limited by the small sample size and retrospective design.

CONCLUSIONS

This study, although small, suggests that rituximab is a reasonable first-line treatment option for indolent CBCL with multiple lesions where local treatment is not effective or desirable.

Marginal zone B-cell non-Hodgkin's lymphoma of mucosa-associated lymphoid tissue type: imaging findings

OBJECTIVE

The aim of this essay is to describe the imaging features of marginal zone B-cell lymphoma of the mucosa-associated lymphoid tissue (MALT) type throughout various organs.

CONCLUSION

Awareness of the expected locations of MALT lymphoma combined with knowledge of the incidence and imaging findings leads to accurate diagnosis of lesions suspicious for this disorder and helps to differentiate this disease from other abnormalities.

[Extranodal diffuse large B-cell lymphoma--an organotypic disease?]

Roughly 30-40% of diffuse large B-cell lymphomas (DLBCL) arise primarily in extranodal sites. Most frequently, they occur in the gastrointestinal tract, especially in the gastric mucosa. They also occur in the central nervous system, as testicular lymphomas, in the lungs, or in the skin. Morphologically, they show the whole spectrum of peripheral B-blasts: centroblasts, immunoblasts, or plasmoblasts. Thus, there is no actual difference in their cytomorphological presentation compared to their nodal-and frequently systemic-counterparts. However, recent data point to profound differences in primary extranodal DLBCL compared to primary nodal tumors, as well as to each other, frequently relating to their molecular characteristics and especially implying organotypic features. These characteristics may relate to a particular organotypic site of origin, or the particular clinico-pathogenetic setting in which the tumors arise. This is exemplified in the description of the DLBCL subtypes as defined by the World Health Organization classification (mediastinal or intravascular B-cell lymphoma; primary effusion lymphoma). On the other hand, primary extranodal DLBCL are frequently characterized by a particular (cyto-)genetic constitution, often related to their site of origin. Finally, some preliminary data on gene expression profiling strongly argue in favor of particular gene signatures for primary extranodal DLBCL, and hence in favor of particular organotypic transformation pathways.

[Cutaneous B-cell lymphoma. Classification and diagnostics]

Primary cutaneous B-cell lymphomas include cutaneous follicle centre lymphoma (PCFCL), cutaneous marginal zone B-cell lymphoma (PCMZL) and cutaneous diffuse large B-cell lymphoma (PCLBCL) "leg type" which are the three main types in the new WHO-EORTC classification for cutaneous lymphomas. PCFCL and PCMZL are indolent lymphomas with an excellent prognosis while PCLBCL shows an aggressive clinical course. All three types must be distinguished from a secondary skin involvement by systemic lymphomas. Since histological and immunohistochemical findings are not decisive, making this distinction requires appropriate staging procedures. In contrast, the pathologist can make an important contribution to the differential diagnosis between neoplastic and reactive cutaneous lymphoproliferations.