Primary cutaneous lymphoproliferative disorders with dual lineage rearrangement

We present a series of 15 cases of cutaneous lymphoma and pseudolymphoma with dual lineage rearrangement identified among approximately 1200 cases of cutaneous lymphoproliferative disorders assessed in our 4 institutions during the last 8 years in which the results of both T-cell receptor and immunoglobulin heavy chain rearrangement investigations were available. On the basis of the clinicopathologic information, the cases were retrospectively subdivided into 2 categories: (1) cases with definite features of cutaneous lymphoma or pseudolymphoma (n = 11) and (2) cases with unclassifiable disease (n = 4). The detection of dual genotype in the first group did not influence the final diagnosis; 7 cases represented cutaneous B-cell lymphomas, 3 pseudolymphomas, and 1 case lymphomatoid papulosis. The presence of monoclonal T-cell receptor-gene rearrangements in these cases may be explained either by monoclonal or oligoclonal expansion of exuberant T cells (or B cells in case of lymphomatoid papulosis) or by lineage infidelity. Three patients with unclassifiable disease had several clinical and histopathologic features in common. They were elderly, presented with solitary lesions, were in good general health and histopathologically demonstrated a dense multinodular infiltrate containing approximately an equal number of T and B cells and a high number of histiocytes forming granulomas, with prominent granulomatous features in 2 cases. B cells were either scattered with the infiltrate or formed collections vaguely resembling follicles; Reed-Sternberg-like cells were seen in 2 cases. B cells showed expression neither of immunoglobulin light chain. The T-cell component was represented mainly by small, well-differentiated lymphocytes or slightly pleomorphic cells, with some medium-sized convoluted cells. Epstein-Barr virus was not detected by polymerase chain reaction. The exact classification of these cases is unknown; they differ histopathologically from previously published cases of bigenotypic cutaneous lymphomas. They may merely represent a growth or reactive pattern, but, on the other hand, may be low-grade lymphomas. If so, they may be histopathologically related to cutaneous Hodgkin disease, T-cell/histiocyte-rich large B-cell lymphoma, or composite lymphomas. Further reports are needed to identify these lesions to clarify their nature and biologic potential.     

T-cell-rich B-cell lymphoma presenting in skin

We reviewed our experience with six T-cell-rich B-cell lymphomas (TRBL) presenting in skin. Immunohistochemical studies were performed on all biopsies. The lymphoid population consisted mainly of CDS and/or UCHL-1 (CD45RO) positive T cells. 5 to 15% of the lymphoid cells stained for the B-cell marker L26 (CD20). Monoclonality of the B-cell component was demonstrated in all cases, utilizing either light chain restriction (5 cases) or clonal immunoglobulin heavy chain gene rearrangement by polymerase chain reaction (PCR) (2 cases). One case was confirmed to be monoclonal by both techniques. Additionally, no clonal rearrangements of the T-cell receptor gamma gene were observed. There was considerable morphological variety in these cases. In H&E stained sections, the differential diagnosis included pseudolymphoma, peripheral T-cell lymphoma, Hodgkin's disease, Lennert's lymphoma and a MALT lymphoma. A significant component of monoclonal plasma cells was present in 3 of 6 cases, suggesting a possible origin from cutaneous immunocytoma. In fact, one of our cases was a biphasic lymphoma displaying TRBL with a small focus of immunocytoma. We conclude that immunophenotypic analysis is necessary for the diagnosis of TRBL. Pathologists should be aware of this type of cutaneous B-cell lymphoma to avoid misinterpretation as a pseudolymphoma.     

Polymerase chain reaction analysis of immunoglobulin gene rearrangement in cutaneous lymphoid hyperplasias. French Study Group for Cutaneous Lymphomas

The differential diagnosis of cutaneous lymphoid hyperplasia and B-cell lymphoma may be difficult. Whether the detection of clonal immunoglobulin gene rearrangement in the cutaneous lesion is predictive of a malignant outcome remains controversial. We therefore studied cases of cutaneous lymphoid hyperplasia by polymerase chain reaction analysis. DESIGN: Retrospective study of patients seen between 1988 and 1996. SETTING: Two dermatology university departments. PATIENTS: Twenty-four patients with cutaneous lymphoid hyperplasias were included according to clinical, histopathological, and immunophenotypic criteria. MAIN OUTCOME MEASURES: Clinical, histopathological, and laboratory findings. RESULTS: There were 13 men and 11 women (mean age, 49 years) who presented with erythematous or violaceous papules or nodules. The lesions were unique in 13 cases and multiple in 11 cases. All patients had immunochemical evidence of a mixed T- and B-cell infiltrate with polytypic B cells. Polyclonality was demonstrated in 23 patients, whereas a dominant B-cell clone was detected in 1 patient. No lymphoma developed during the follow-up (median, 4 years). In the same period, we studied 53 cases of B-cell lymphomas. Thirty-five (66%) of the 53 cases had a detectable clonal immunoglobulin gene rearrangement. CONCLUSIONS: In the majority of our cases, polyclonality demonstrated by polymerase chain reaction analysis was in accordance with the diagnosis of cutaneous lymphoid hyperplasia. In 1 of the 24 patients, the presence of a B-cell clone could be evidenced. This fact did not modify the treatment as there were no histological or immunophenotypic signs suggestive of a lymphoma.     

Gene rearrangements in lymphoma. Applications to dermatopathology

Clonality is regarded as an important diagnostic feature of B-cell lymphomas, but until recently the clonality of T-cell proliferations could not be directly determined. Elucidation of the genetic events in lymphocytic differentiation has led to the development of an assay for clonality in both B- and T-cell infiltrates. Clonal rearrangement of the immunoglobulin or T-cell receptor genes can be detected by the Southern blot technique. Such rearrangements provide evidence of clonal proliferation, which, in the proper context, can be regarded as a sign of malignancy. The presence of gene rearrangements in poorly differentiated neoplasms may serve as evidence of hematopoietic differentiation, and the pattern of such rearrangements may point to either T- or B-cell lineage. Specific applications to dermatopathology include the evaluation of skin biopsy specimens for cutaneous lymphoma, evaluation of peripheral blood specimens for detection of Sézary's syndrome, and evaluation of lymph nodes and blood for the staging of mycosis fungoides.     

World Health Organization classification of hematopoietic and lymphoid tissues: implications for dermatology

The new World Health Organization (WHO) classification of hematopoietic and lymphoid malignancy represents the first worldwide consensus document on the classification of lymphoma/leukemia. Its aim is to supercede all existing classification systems, including the Revised European American Classification (REAL), and the organ-based classification of cutaneous lymphoma proposed in 1997 by the European Organization for Research and Treatment of Cancer (EORTC) cutaneous lymphoma project group. This article compares the REAL, EORTC, and WHO classifications with particular reference to cutaneous lymphoma. It identifies those entities that have been adopted from the EORTC classification, and illustrates important new entities in the category of cytotoxic T-/NK-cell lymphomas that characteristically present in the skin or subcutaneous tissue. However, WHO is not an organ-based classification and some categories (eg follicular B-cell lymphoma and peripheral T-cell lymphoma) include both cutaneous and systemic diseases, and these may have very different prognoses. It is, therefore, important that cancer registries are capable of recording sites of involvement for both B- and T-cell lymphomas so that the incidence and prognosis of cutaneous lymphomas can be established from national data sets in future years.     

Significance of non-lymphoid (''accessory'') cells in malignant lymphomas and pseudolymphomas of the skin

We investigated the co-distribution of lymphocyte subpopulations and non-lymphoid 'accessory' cells in 35 cases of cutaneous lymphoproliferative diseases (T-cell lymphoma, 10 cases; B-cell lymphoma, 17 cases; pseudolymphoma, 8 cases) using immunohistochemical methods. T-zone histiocytes and particularly Langerhans cells were abundant in all cutaneous T-cell lymphomas, but were also found in B-cell lymphomas. T-zone histiocytes were associated with T-lymphocytes, especially T-helper cells, but not with T-suppressor cells. Dendritic reticulum cells were essentially confined to well differentiated germinal centres. Macrophages occurred in both lymphomas and pseudolymphomas without definite relationship with either B- or T-cells. In malignant lymphomas of high grade malignancy, macrophages represented the only non-lymphoid cell type. Our results indicate that malignant lymphoid cells, like normal lymphocytes, require definite micro-environments which are, at least in part, maintained by certain non-lymphoid cells.     

Cutaneous lymphomas showing prominent granulomatous component: clinicopathological features in a series of 16 cases

Background  The presence of a prominent granulomatous tissue reaction in skin biopsies from primary cutaneous or systemic malignant lymphomas with secondary cutaneous involvement is a rare but well-known phenomenon.
Objective  This paper aims to characterize and study a series of cutaneous lymphomas showing a prominent granulomatous component.
Patients and methods  The clinical, histopathological and evolutive features of granulomatous variants of mycosis fungoides (5 patients, 2 of them associating 'granulomatous slack skin' features), Sézary syndrome (1 patient), CD30⁺ cutaneous T-cell lymphoma (2 patients), CD4⁺ small/medium pleomorphic cutaneous T-cell lymphoma (1 patient), primary cutaneous B-cell lymphoma (3 patients) and peripheral T-cell lymphoma with secondary epithelioid granulomatous cutaneous involvement (4 patients) were reviewed.
Results  The observed features were clinically non-distinctive. Only those cases presenting with granulomatous slack skin features were clinically suspected (2 patients). Non-necrotizing granulomata (11 patients) and granuloma annulare-like (4 patients) were the most frequently observed histopathological patterns. In five cases, no diagnostic lymphomatous involvement was initially observed. From our series, no definite conclusions regarding prognosis could be established.
Conclusion  The diagnosis of cutaneous lymphoma may be difficult when a prominent cutaneous granulomatous inflammatory infiltrate obscures the true neoplastic nature of the condition. However, the presence of concomitant lymphoid atypia may help to suspect the diagnosis. In doubtful cases, the clinical evolution and the demonstration of a monoclonal lymphoid B- or T-cell population may lead to a definite diagnosis.

Conflicts of interest

None declared.     

Non-Hodgkin lymphoma of the skin excluding mycosis fungoides and cutaneous involvement of adult T-cell leukemia/lymphoma*

Forty-nine cases of cutaneous malignant lymphoma were reviewed in order to analyze the clinicopathological features of these neoplasms. Excluding 13 cases of mycosis fungoides and 4 cases of cutaneous involvement of proven adult T-cell lymphoma/leukemia, the remaining 32 cases were further classified according to their pathological and clinical features. There were 12 primary cutaneous lymphomas, 15 cases of secondary cutaneous involvement of systemic lymphoma, and 5 cases of concurrent skin and lymph node involvement. Histologically, large cell lymphoma predominated in both primary and secondary cutaneous lymphomas. Immunohistochemical study using monoclonal antibodies reactive with B- and T-cells in paraffin sections revealed the cellular lineage in 30 cases. Nineteen cases were of T-cell origin and 11 cases were of B-cell derivation. The prognosis of these patients was rather poor; 25 patients died within 5 years. The predominance of T-cell lymphoma contrasts with a higher frequency of cutaneous B-cell lymphoma in Western countries. As the clinicopathological features of cutaneous lymphomas are diverse, it is suggested that cutaneous lymphomas should be classified and studied in a similar way to their nodal counterparts.     

Intraepidermal localization of the clone in cutaneous T-cell lymphoma.

BACKGROUND: No immunohistologic techniques are currently available to demonstrate clonality of T-cell lymphomas. Monoclonal antibodies to the variable region of the T-cell receptor (TCR) have been produced that identify minor populations of normal peripheral blood T lymphocytes. OBJECTIVE: We investigated the expression of TCR V-region genes in cutaneous lymphomas to determine whether immunostaining with these antibodies may be a simple method to detect clonal T-cell proliferations and help to distinguish benign lymphoid infiltrates from malignant lymphoma. METHODS: Cutaneous samples were obtained from 18 cutaneous T-cell lymphomas (14 mycosis fungoides, 1 Sézary syndrome, 2 pleomorphic T-cell lymphoma, and 1 large cell anaplastic lymphoma) and 8 benign lymphoid infiltrates. Frozen sections were incubated with monoclonal antibodies and stained by the alkaline phosphatase-antialkaline phosphatase technique. Staining was performed with a panel of 7 anti-TCR V-region antibodies, 6 T-cell markers, 1 anti-beta chain antibody, and 1 anti-delta chain antibody. RESULTS: Clonality could be demonstrated in 2 of 18 cutaneous lymphomas. We observed the strictly intraepidermal localization of clonal proliferation in one case of early-stage mycosis fungoides. CONCLUSION: Anti-TCR V-region antibodies may identify a strictly epidermotropic clone in early mycosis fungoides. However, the panel of antibodies currently available stains only a minority of cutaneous T-cell lymphomas. The usefulness of these antibodies as a clonotypic marker needs to be reevaluated when a larger panel of antibodies becomes available.     

Cutaneous involvement in lymphoblastic lymphoma

Lymphoblastic leukemia/lymphoma (LBL) is a malignant neoplasm of precursor lymphocytes of B- or T-cell phenotype. Involvement of the skin is relatively uncommon. We examined retrospectively the clinicopathologic, immunophenotypic, and molecular genetic features of six patients with cutaneous involvement of LBL (B-LBL=5; T-LBL=1). Patients presented clinically with solitary, large tumors located on the head (3 cases) or the back (1 case), or with generalized tumors (2 cases). Ulceration was uncommon. In two patients the onset of skin lesions was concomitant to the diagnosis of lymphoblastic leukemia. Histopathologic examination showed in all cases a dense, diffuse, monomorphous infiltrate located in the entire dennis and subcutaneous fat. A typical "starry sky" pattern was observed in the majority of the lesions. In some areas neoplastic cells were aligned in a "mosaic-like" fashion. Cytomorphologically, medium sized lymphoid cells with round or convoluted nuclei, inconspicuous nucleoli and scant cytoplasm predominated. There were no significant differences in the histopathologic features of skin lesions in T- and B-LBL. In B-LBL, CD79a was more useful than CD20 in determining the phenotype of neoplastic cells (4/5 cases positive for CD79a as compared to 2/5 cases positive for CD20). TdT, CD10 and CD43 were positive in 4 cases, CD34 in 2. The case of T-LBL revealed positivity for CD1a, CD3, CD43 and TdT, and negativity for CD34 and for B-cell markers. All neoplasms were positive for CD99 and bcl-2, and showed a high proliferation rate. Molecular genetic analysis of J(H) and T-cell receptor (TCR) genes performed using a polymerase chain reaction technique revealed a monoclonal rearrangement of J(H) genes in all five B-LBLs. One of these cases showed also a concomitant TCR-gamma gene rearrangement. A monoclonal rearrangement of the TCR-gamma gene was detected in the case of T-LBL. Our study shows that skin lesions of LBL present characteristic clinicopathologic and molecular features allowing the differentiation from other cutaneous lymphomas, even in cases without clinical history of previous precursor lymphoblastic leukemia/lymphoma.     

Cutaneous lymphoid hyperplasia and other lymphoid infiltrates of the breast nipple: a retrospective clinicopathologic study of fifty-six patients

This study characterizes the clinicopathological spectrum of lymphoproliferations involving the breast nipple and/or areola. Morphologic, immunohistochemical, molecular-genetic, and clinical features of 58 specimens from 56 patients were analyzed. They were re-diagnosed as cutaneous lymphoid hyperplasia (CLH, n = 44); other benign lymphoid infiltrates (OBLI, n = 8); peripheral T-cell lymphoma, not otherwise specified (n = 1); cases with overlapping features of CLH and B-cell lymphoma (n = 3), one of them composed of spindle cells. Cutaneous lymphoid hyperplasia infiltrates were dense, composed mainly of B cells forming follicles with germinal centers (GC). Cutaneous lymphoid hyperplasia frequently showed features suggesting a malignancy as coalescing follicles with non-polarized germinal centers lacking mantle zones, and smudged infiltrates of lymphoid cells spreading into collagen (often as "Indian files"), smooth muscle, vessel walls, and nerve sheaths. Only two cutaneous lymphoid hyperplasias recurred; otherwise all patients are without disease (mean follow-up 62 months). Monoclonal rearrangement of immunoglobulin heavy chain gene was detected in five, and of T-cell receptor gamma gene in two cutaneous lymphoid hyperplasias using polymerase chain reaction (PCR), but the patients fared well too. In 47% of cases Borrelia burgdorferi was detected by polymerase chain reaction and/or serology, of which one was monoclonal. We conclude that cutaneous lymphoid hyperplasia is the most common lymphoproliferation of the breast nipple, rarely recognized clinically, and often overdiagnosed histologically as lymphoma.     

Cutaneous peripheral T-cell lymphoma of cytotoxic phenotype mimicking extranodal NK/T-cell lymphoma

Cutaneous peripheral T-cell lymphoma unspecified is a rare neoplasm that is infrequently associated with Epstein-Barr virus (EBV) infection. In contrast, extranodal natural killer (NK)/T-cell lymphoma, although also rare, is known to be strongly associated with EBV and occurs most commonly in the nasal region. We report the case of a 55-year-old male who presented with fever and an indurated cutaneous plaque with ulceration. This cutaneous neoplasm showed diffuse dermal lymphomatous infiltration and tumor necrosis, with neoplastic cells expressing CD2, cytoplasmic CD3 (CD3ε), CD8, CD16, CD30, T-cell intracellular antigen-1, and granzyme B but not CD56, BF1, or T-cell receptor (TCR) δ1. Furthermore, the tumor cells were noted to be diffusely positive for EBV by in situ hybridization. A monoclonal TCR gene rearrangement was demonstrated. The disease showed an aggressive clinical course, and the patient died within 3 weeks of diagnosis without complete staging or chemotherapy. According to the 2005 World Health Organization/European Organization for Research and Treatment of Cancer scheme for cutaneous lymphoma and the 2008 WHO classification for lymphoid neoplasms, our case would have been classified as a nasal type extranodal NK/T-cell lymphoma with T-cell lineage. However, the expressions of CD8 and CD16, in addition to a monoclonal TCR gene rearrangement, are unusual findings in NK/T-cell lymphoma, and we believe such a phenotype/genotype should be more appropriately classified as an EBV-positive peripheral T-cell lymphoma, unspecified with a cytotoxic phenotype. Detailed clinicopathologic and molecular studies of similar cases may shed light on the prognostic impact of NK vs. T-cell lineage on extranodal NK/T-cell lymphomas.     

Detection of Epstein-Barr virus genome in primary cutaneous T and B cell lymphomas and pseudolymphomas

The Epstein-Barr virus (EBV) genome has recently been identified in Hodgkin's disease (HD) and nodal non-Hodgkin's lymphomas (NHL). In order to elucidate the possible aetiopathogenetic role of EBV in benign and malignant lymphoproliferative disorders we investigated skin specimens from 24 patients with a primary cutaneous lymphoproliferative disorders (10 T-cell lymphomas 6 B-cell lymphomas and 8 pseudolymphomas) and from 22 normal individuals for the presence of EBV DNA using the polymerase chain reaction (PCR) technique and in situ hybridization (ISH) on formalin-fixed paraffin-embedded tissue sections. EBV DNA was identified by PCR in one of two cases of mycosis fungoides, in one of seven cases of pleomorphic T-cell lymphomas, in one case of centro-blastic (CB) lymphoma of six B-cell lymphomas, and in three of eight pseudolymphomas. The EBV genome was also found in 2 of 22 specimens of normal skin. The small EBV-encoded nuclear RNAs, EBERs, were not detected in any PCR-positive sample by ISH. Based on our PCR and ISH findings, EBV does not seem to play a significant role in the development of cutaneous lymphomas.     

Improved sensitivity of T-cell clonality detection in mycosis fungoides by hand microdissection and heteroduplex analysis

BACKGROUND: The presence of a dominant T-cell clone is an important diagnostic criterion in cutaneous T-cell lymphomas (CTCLs) and in atypical T-cell cutaneous infiltrates. Procedures based on polymerase chain reaction (PCR) are the most sensitive to detect clonality, but heteroduplex analysis is less sensitive than other methods such as denaturing gradient gel electrophoresis. OBJECTIVE: To assess whether a gross hand microdissection of the superficial (papillary) portion of the dermal infiltrate may improve the sensitivity of T-cell clonality detection by PCR-heteroduplex analysis in CTCL. SETTING: Regional university hospital (secondary or tertiary referral center).Patients A total of 29 patients with a definite diagnosis of mycosis fungoides based on typical histologic and immunophenotypic features were selected with patch (16) or plaque (13) stages. MAIN OUTCOME MEASURES: Assessment of T-cell clonality by PCR amplification of the T-cell receptor gamma chain followed by heteroduplex analysis using DNA extracted from the entire biopsy specimen and after gross microdissection of the subepidermal bandlike dermal infiltrate. RESULTS: T-cell clonality was demonstrated in 24 of 29 cases when hand microdissection was used compared with 16 of 29 cases with DNA analysis from entire biopsy specimens; thus, hand microdissection resulted in a sensitivity improvement of approximatively 50%. CONCLUSIONS: Hand microdissection substantially improves the detection of a T-cell clone in CTCL when using a PCR-heteroduplex analysis and could be used routinely in the clinical evaluation of T-cell infiltrates. Importantly, the microdissection method was found to be more useful for the detection of T-cell clones in early patch stages of CTCL than in plaque-stage disease.     

Clonality in sarcoidosis, granuloma annulare, and granulomatous mycosis fungoides

The histological discrimination of granulomatous cutaneous T-cell lymphomas (CTCLs) from reactive granulomatous disorders such as sarcoidosis and granuloma annulare (GA) may be difficult due to overlapping histological features. We analyzed the T-cell receptor gene rearrangement in sarcoidosis and GA to investigate the value of the detection of clonal T cells as an adjunctive diagnostic marker in the differentiation between sarcoidosis and GA versus granulomatous CTCLs. Rearrangement of T-cell receptor γ genes was examined by the use of automated high-resolution polymerase chain reaction fragment analysis in 35 cases of sarcoidosis and 15 cases of GA and compared with a series of 19 cases of granulomatous CTCLs. A monoclonal T-cell population was found in none of the cases of sarcoidosis and in 2 of 15 cases of GA (13%). In granulomatous CTCLs, a neoplastic T-cell clone was detected in 94%. Presence of clonal T cells argues in favour of a granulomatous CTCL, while a polyclonal T-cell population makes the presence of a sarcoidosis or a GA more likely. The analysis of T-cell clonality is a useful diagnostic adjunct in the differentiation between sarcoidosis and GA from granulomatous CTCLs.     

True histiocytic lymphoma (monocytic sarcoma)

The clinical, histological, immunophenotypic, and genotypic characteristics of two cases of cutaneous genuine histiocytic lymphoma are described. Both cases presented as cutaneous lesions. Both patients remain alive and free of disease at 26 and 10 months after the diagnosis and after having been treated with polychemotherapy. Neither peripheral blood nor bone marrow infiltration was detected in either case. Histological and immunophenotypic examination showed dense, diffuse dermic infiltrates of mononuclear cells with positive macrophage-associated markers (CD11c, CD68), and negative T- or B-cell-associated antigens. A germline configuration of both T-cell receptor and immunoglobulin genes was observed in gene rearrangement studies. Although most of the cases that have been diagnosed as histiocytic lymphoma or malignant histiocytosis in the past turned out to be B- or T-large-cell lymphomas, a small number of cases (two in our consecutive series of 350 cases) show characteristics of monocyte-macrophage tumors. We stress the importance of the CD68 marker in the diagnosis of true histiocytic lymphoma, suggest a therapeutic approach based on similarities with monocytic leukemia, and propose the use of the term monocytic sarcoma for this clinicopathological presentation.     

Automated kappa and lambda light chain mRNA expression for the assessment of B-cell clonality in cutaneous B-cell infiltrates: its utility and diagnostic application

INTRODUCTION: Primary cutaneous B-cell lymphoma (1 degrees CBCL) accounts for 25% of all lymphomas. The difficulty in distinction of reactive from neoplastic B-cell infiltrates prompts the use of molecular diagnostic adjuncts. While T-cell clonality can be seen in various reactive states, clonal B-cell infiltrates are often neoplastic; standard assays employed include polymerase chain reaction (PCR) or Southern blot analysis to assess heavy chain rearrangement. We sought to assess the utility of kappa (kappa) and lambda (lambda) mRNA expression using the Ventana automated assay (Ventana Medical Systems, Tucson, AZ, USA) in the analysis of atypical cutaneous B-cell lymphoid infiltrates. MATERIALS AND METHODS: Multiple 4 micro m sections of paraffin-embedded, formalin-fixed skin biopsies from 31 patients with CBCL were placed on silane-coated slides, deparaffinized, then digested in pepsin (5 mg/ml) for 30 min at 37 degrees C. Fluorescein-tagged oligoprobes and tissue mRNA were denatured at 80 degrees C for 5 min, hybridized for 2 h at 37 degrees C, and incubated with antifluorescein alkaline phosphatase conjugates. Detection of the probe target complex employed nitroblue tetrazolium and bromochloroindolyl phosphate conjugates with a nuclear fast red counterstain. A kappa : lambda ratio > 3 : 1 was held to represent kappa light chain restriction and a kappa : lambda ratio 相似文献   

Coexistent cutaneous T-cell lymphoma and B-cell chronic lymphocytic leukaemia

Three patients with cutaneous T-cell lymphoma (CTCL) are reported who had concurrent B-cell chronic lymphocytic leukaemia (B-CLL). The separate lineage and clonal nature of the individual lymphoid malignancies were confirmed by gene-rearrangement analysis. The chronology of the illnesses did not support the hypothesis that CTCL predisposes to the development of B-cell proliferative disorders. There was no clear association with immunosuppressive therapy, and HTLV-1 studies were negative in all patients. Consequently, we speculate that a lymphoid stem cell defect, which may lead to the development of either aberrant B- or T-cell clones, may be responsible for such cases of dual lymphoid neoplasia.     

Cutaneous B-cell lymphoma

The various morphologic and functional subtypes of nodal B-cell lymphomas can also be found in the skin. These reflect the various steps of lymphocyte differentiation including maturation from the pre-B lymphocyte to the well-differentiated B2 lymphocyte or plasma cell in the peripheral blood. The subtypes of cutaneous B-cell lymphomas have been discussed (Kiel classification); the percentages indicate the frequencies of the subtypes among a total of 736 cutaneous lymphomas of both T-cell and B-cell origin: Lymphocytic lymphoma (7 per cent). Immunoglobulin-producing lymphomas, including the rate plasmacytoma of the skin, lymphoplasmacytoid immunocytoma, which represents the largest group of cutaneous B-cell lymphoma (12 per cent), and immunoblastic lymphoma, which is the most aggressive form in this group (8 per cent). Cutaneous B-cell lymphoma arising from or related to follicular center cells, including centrocytic lymphoma (7 per cent), mantle-cell lymphoma, centroblastic/centrocytic lymphoma (6 per cent), the highly malignant centroblastic lymphoma (4 per cent), and lymphoblastic lymphoma, Burkitt type. The Ann Arbor staging system is not applicable to cutaneous B-cell lymphoma; therefore, a TNM staging system has been proposed. The diagnosis of cutaneous B-cell lymphoma is based primarily on cytomorphologic features. Differentiation of cutaneous B-cell lymphoma from pseudolymphoma of the skin cannot be based on a single criterion; a spectrum of characteristic features must be evaluated. Analysis of the infiltrating cells in cutaneous B-cell lymphoma using monoclonal antibodies demonstrates that the proliferation of the neoplastic clone is accompanied by a mixture of accessory cells of various origins, including T cells, macrophages, and dendritic reticulum cells. As in nodal B-cell lymphomas, several factors may be involved in the generation of cutaneous B-cell lymphoma, including persistent antigenic stimulation and loss of regulatory mechanisms for lymphocyte proliferation and differentiation in conjunction with environmental and other factors.