Patty M. Jansen

Reclassification of 300 Primary Cutaneous B-Cell Lymphomas According to the New WHO–EORTC Classification for Cutaneous Lymphomas: Comparison With Previous Classifications and Identification of Prognostic Markers

PURPOSE In the new WHO-European Organisation for Research and Treatment of Cancer (WHO-EORTC) classification for cutaneous lymphomas three major groups of primary cutaneous B-cell lymphoma (CBCL) are distinguished: primary cutaneous marginal zone B-cell lymphoma (PCMZL) and primary cutaneous follicle center lymphoma (PCFCL) with a good prognosis, and primary cutaneous large B-cell lymphoma, leg type (PCLBCL-LT), with an intermediate-level prognosis. This study aimed to assess the clinical significance of the new classification compared with previous classification schemes (EORTC 1997; WHO 2001) and to define prognostic factors within the newly defined categories. PATIENTS AND METHODS In the present study clinical data and histologic sections of 300 patients with CBCL, formerly classified according to the EORTC classification, were reviewed and reclassified according to the WHO and the new WHO-EORTC classification schemes. RESULTS After reclassification, the study comprised 71 patients with PCMZL, 171 patients with PCFCL, and 58 patients with PCLBCL-LT, showing 5-year disease-specific survivals of 98%, 95%, and 50%, respectively. When compared with the EORTC and WHO schemes, 5.3% and 36.3% of patients with CBCL were reclassified into another prognostic category. Multivariate analysis of PCFCL revealed localization on the leg and expression of FOXP1 as independent parameters associated with a poor prognosis. Expression of Bcl-2 or MUM-1 had no significant effect on survival in this group. In PCLBCL-LT, no independent prognostic parameters were found. CONCLUSION These results emphasize the clinical significance of the WHO-EORTC classification, but suggest that within the group of PCFCL, distinction should be made between lymphomas presenting on the legs and lymphomas presenting at other sites.

Unique polycomb gene expression pattern in Hodgkin's lymphoma and Hodgkin's lymphoma-derived cell lines

Human Polycomb-group (PcG) genes play a crucial role in the regulation of embryonic development and regulation of the cell cycle and hematopoiesis. PcG genes encode proteins that form two distinct PcG complexes, involved in maintenance of cell identity and gene silencing patterns. We recently showed that expression of the BMI-1 and EZH2 PcG genes is separated during normal B-cell development in germinal centers, whereas Hodgkin/Reed-Sternberg (H/RS) cells co-express BMI-1 and EZH2. In the current study, we used immunohistochemistry and immunofluorescence to determine whether the binding partners of these PcG proteins are also present in H/RS cells and H/RS-derived cell lines. PcG expression profiles were analyzed in combination with expression of the cell cycle inhibitor p16INK4a, because experimental model systems indicate that p16 is a downstream target of Bmi-1. We found that H/RS cells and HL-derived cell lines co-express all core proteins of the two known PcG complexes, including BMI-1, MEL-18, RING1, HPH1, HPC1, and -2, EED, EZH2, YY1, and the HPC2 binding partner, CtBP. Expression of HPC1 has not been found in normal mature B cells and other malignant lymphomas of B-cell origin, suggesting that the PcG expression profile of H/RS is unique. In contrast to Bmi-1 transgenic mice where p16INK4a is down-regulated, 27 of 52 BMI-1POS cases of HL revealed strong nuclear expression of p16INK4a. We propose that abnormal expression of BMI-1 and its binding partners in H/RS cells contributes to development of HL. However, abnormal expression of BMI-1 in HL is not necessarily associated with down-regulation of p16INK4a.

Prognostic factors in transformed mycosis fungoides: a retrospective analysis of 100 cases

Large cell transformation (LCT) in mycosis fungoides (MF) is generally associated with an aggressive clinical course and poor survival, requiring aggressive therapeutic approach. However, a proportion of cases may follow an indolent clinical course. To identify prognostic factors, we analyzed the prognostic relevance of clinical, histologic, and immunophenotypical features in a large cohort of transformed MF patients, including 75 patients with only skin lesions, 19 patients with LCT in skin and lymph nodes, and 6 patients with LCT in lymph nodes only. Multivariate analysis of the total group showed that CD30 negativity, folliculotropic MF, extent of skin lesions and extracutaneous transformation were associated with reduced disease-specific survival (DSS) and, except for CD30 negativity and folliculotropic MF, also overall survival. In a multivariate analysis of 75 patients with only skin lesions at the time of LCT, CD30 negativity, folliculotropic MF and extent of skin lesions were independent parameters for both DSS and overall survival. Using the most discriminating parameters as a prognostic index, in both study groups differences in DSS between patients with 0-1 unfavorable prognostic factor(s) and ≥ 2 unfavorable prognostic factors were statistically significant (P < .001). This prognostic index may be helpful in predicting prognosis and selecting the most appropriate treatment in patients with transformed MF.

Indolent CD8-positive lymphoid proliferation of the ear: a distinct primary cutaneous T-cell lymphoma?

The authors report 4 cases of cutaneous lymphoproliferation unusual by their histology and their clinical presentation. Each presented with a history of a slow growing nodule on the ear. Despite the indolent clinical evolution, the histology suggested a high-grade lymphoma. All lesions consisted of a dense, diffuse proliferation of monomorphous medium-sized T cells throughout the dermis and subcutis. There was no epidermotropism and a grenz zone was clearly present in each case. The tumor cells displayed irregular blastlike nuclei, with small nucleoli and clear chromatin and had a CD3+, CD8+, CD4−, TIA1+, granzyme B−immunophenotype with a loss of other T-cell antigens. The 3 cases with available material for polymerase chain reaction studies displayed a monoclonal T-cell rearrangement of the T-cell receptor-γ chain. These cases do not correspond to a recognized cutaneous T-cell lymphoma as described in the recent WHO/EORTC classification. The apparent striking propensity for the ear suggests that they might represent a specific entity. Further cases are needed to confirm this hypothesis. It is important for such indolent lesions to be known to avoid over treatment.

Expression of programmed death-1 in primary cutaneous CD4-positive small/medium-sized pleomorphic T-cell lymphoma, cutaneous pseudo-T-cell lymphoma, and other types of cutaneous T-cell lymphoma.

In this study we investigated whether programmed death-1 (PD-1) could serve as a useful diagnostic marker to differentiate between primary cutaneous CD4+ small/medium-sized pleomorphic T-cell lymphoma (PCSM-TCL) and cutaneous pseudo-T-cell lymphomas on the one hand and other types of cutaneous T-cell lymphomas (CTCLs) on the other. Formalin-fixed, paraffin-embedded skin biopsies from 26 patients with PCSM-TCL or pseudo-T-cell lymphoma, including 1 patient with a lymphomatoid drug eruption, and 52 skin biopsies from other types of CTCLs were stained for PD-1. In addition, PD-1-positive cases were stained with antibodies against BCL6, CXCL13, and CD10 to determine a possible relationship with follicular helper T (TFH) cells. In all 26 cases of PCSM-TCL or pseudo-T-cell lymphoma, the medium-sized to large-sized atypical T cells consistently expressed PD-1, BCL6, and CXCL13 but not CD10. PD-1 expression was found in only 2 of 21 cases of mycosis fungoides and in only 2 of 16 cases of cutaneous peripheral T-cell lymphoma, unspecified. All 4 patients with an aggressive epidermotropic cytotoxic CD8+ CTCL and all 11 cases with a primary cutaneous CD30+ lymphoproliferative disorder were negative for PD-1. In conclusion, PD-1 is typically expressed by atypical cells in PCSM-TCL and pseudo-T-cell lymphoma but is not expressed or is rarely expressed in other types of CTCLs. Therefore, it may serve as a suitable adjunct in differential diagnosis. Our results demonstrate that the atypical cells in PCSM-TCL and pseudo-T-cell lymphomas share a common TFH phenotype and support the view that most cases classified nowadays as PCSM-TCL are identical to cutaneous pseudo-T-cell lymphomas described previously.

A Meta-Analysis of Gene Expression Data Identifies a Molecular Signature Characteristic for Tumor-Stage Mycosis Fungoides

Mycosis fungoides (MF) is the most common type of primary cutaneous T-cell lymphoma (CTCL). To identify a molecular signature characteristic of MF tumor stage, we used a bioinformatic approach involving meta-analysis of publicly available gene expression data sets combined with previously generated gene expression data. Results for a selection of genes were further refined and validated by quantitative PCR and inclusion of additional controls. With this approach, we identified a profile specific for MF tumor stage, consisting of 989 aberrantly expressed genes, the majority of which (718 genes) are statistically significantly more expressed in MF compared with normal skin, inflamed skin, and normal T cells. As expected, the signature contains genes reflecting the highly proliferative characteristic of this T-cell malignancy, including altered expression of cell cycle and kinetochore regulators. We uncovered details of the immunophenotype, suggesting that MF originates from IL-32-producing cells and identified previously unreported therapeutic targets and/or diagnostic markers, for example, GTSF1 and TRIP13. Loss of expression of the NF-κB inhibitor, NFKBIZ, may partly explain the enhanced activity of NF-κB, which is a hallmark of MF and other CTCLs.

Non-mycosis fungoides cutaneous T-cell lymphomas: report of the 2011 Society for Hematopathology/European Association for Haematopathology workshop.

Primary cutaneous T-cell lymphomas (CTCL) excluding mycosis fungoides (MF) were discussed in 2 sessions of the 2011 Society for Hematopathology/ European Association of Haematopathology Workshop, Los Angeles, CA. Session 2 focused on primary cutaneous CD30+ T-cell lymphoproliferative disorders and their differential diagnosis, including systemic CD30+ T-cell lymphoma secondarily infiltrating the skin. Interesting features like special morphologic variants and atypical phenotypes were presented. In addition, the possibility of rare ALK+ primary cutaneous lymphomas was discussed. Session 3 examined other more uncommon non-MF CTCLs, including subcutaneous panniculitis-like T-cell lymphoma, extranodal NK/T-cell lymphoma, hydroa vacciniforme-like T-cell lymphoma, and rare subtypes of primary cutaneous peripheral T-cell lymphoma, not otherwise specified. In addition, systemic T-cell lymphomas involving the skin secondarily, such as angioimmunoblastic T-cell lymphoma, were included in this session. In this report, novel findings, areas of special interest, and diagnostic challenges emerging from the cases submitted to the workshop will be highlighted. The necessity to integrate histologic, immunophenotypical, genetic, and in particular, clinical data to arrive at the correct diagnosis, and subsequently provide adequate treatment, is emphasized.

IgM Expression on Paraffin Sections Distinguishes Primary Cutaneous Large B-cell Lymphoma, Leg Type From Primary Cutaneous Follicle Center Lymphoma

In the World Health Organization (WHO) 2008 classification 2 main types of primary cutaneous large B-cell lymphomas (PCLBCLs) are distinguished: primary cutaneous follicle center lymphoma (PCFCL) and primary cutaneous large B-cell lymphoma, leg type (PCBCL-LT). PCFCL has a 5-year overall survival rate of 95%, and PCBCL-LT of approximately 50%. Expression profiling studies have shown higher RNA expression of the IgM heavy chain in PCBCL-LT compared with PCFCL. To find out whether this difference could also be demonstrated at the protein level, we performed immunohistochemical staining for B-cell receptor heavy and light chains on skin biopsies from 53 patients with PCFCL and 40 patients with PCBCL-LT. All 40 cases of PCBCL-LT consistently showed cytoplasmic staining for IgM, in 18 of them with coexpression of IgD. In contrast, only 5 of the PCFCL cases showed cytoplasmic staining for IgM and/or IgD, including all 3 PCFCLs presenting on the leg. Hence, staining for IgM on paraffin-embedded sections seems to be an additional tool for differentiating between the 2 entities in clinical pathology practice. Analogous to other nodal and extranodal large B-cell lymphomas, expression of IgM in PCLBCL seems to be related to an activated B cell-like phenotype. Finally, the expression of IgM (and IgD) in this type of lymphoma might imply defective class switch recombination.

Diagnostic and prognostic evaluation of phenotypic markers TRAF1, MUM1, BCL2 and CD15 in cutaneous CD30-positive lymphoproliferative disorders

Background  CD30 is expressed in various types of cutaneous lymphomas, including lymphomatoid papulosis (LyP), primary cutaneous anaplastic large cell lymphoma (C‐ALCL), some cases of mycosis fungoides showing large cell transformation (MF‐TR) and skin localizations of systemic anaplastic lymphoma kinase (ALK)‐positive or ALK‐negative ALCL. Differentiation between these entities is often not possible on the basis of histology alone, but several markers, including TRAF1, MUM1 and BCL2, have been reported to provide additional diagnostic information.

Differential Expression of Programmed Death-1 (PD-1) in Sezary Syndrome and Mycosis Fungoides

OBJECTIVE To determine if there are differences in the expression of programmed death-1 (PD-1) between SS and MF, and in particular erythrodermic MF (E-MF). PD-1 is a marker of follicular helper T (TFH) cells and is expressed by the neoplastic T cells of some types of malignant T-cell lymphoma, including mycosis fungoides (MF) and Sézary syndrome (SS). Reported results of PD-1 staining in MF and SS are, however, conflicting. DESIGN Formalin-fixed, paraffin-embedded skin biopsy specimens were stained for PD-1. In addition, PD-1+ cases were stained with antibodies against BCL6, CXCL13, and CD10 to find possible relationship with TFH cells. SETTING Tertiary referral center for cutaneous lymphomas. PATIENTS Twenty-seven patients with SS and 60 patients with MF, including 8 patients with E-MF. RESULTS In patients with SS, expression of PD-1 by more than 50% of the neoplastic T cells was observed in 24 of 27 cases (89%). In contrast, PD-1 expression by more than 50% of neoplastic T cells was found in only 8 of 60 patients with MF (13%), including only 1 of 8 patients with E-MF (12%). In PD-1+ cases, serial skin sections showed that CXCL13 and BCL6 generally stained 25% to 50% of the PD-1+ cells, while expression of CD10 was uncommon. CONCLUSION The results of the present study show differential expression of PD-1 between SS and MF/E-MF, which provides further support for the view that SS and MF are distinct entities.