Genotypic analysis of cutaneous T-cell lymphomas

Duration of symptoms does not correlate with results of T-cell gene rearrangement studies in patients evaluated for cutaneous T-cell lymphoma

OBJECTIVES

We aimed to determine if clonality on T-cell gene rearrangement studies correlated with duration of cutaneous symptoms in patients with skin disease who are being evaluated for cutaneous T-cell lymphoma (CTCL). Specifically, our goal was to determine if symptom duration could help better optimize sample selection for T-cell gene rearrangement studies.

METHODS

Biopsies were reviewed from patients within both general dermatology clinic and CTCL specialty clinic for clonality results in relation to disease duration.

RESULTS

We did not find an association between duration and clonality in any group.

CONCLUSIONS

The yield of T-cell gene rearrangement studies is similar between shorter and longer duration of disease implying that there is not an optimal duration range in which T-cell gene rearrangement studies are more likely to give a positive result.

Early TCR-beta and TCR-gamma PCR detection of T-cell clonality indicates minimal tumor disease in lymph nodes of cutaneous T-cell lymphoma: diagnostic and prognostic implications

The lymph nodes are generally the first extracutaneous manifestation in patients with cutaneous T-cell lymphoma (CTCL); however, their early involvement is difficult to assess. The aim of our study was to define the diagnostic and prognostic value of T-cell clonality analysis for a more precise assessment of lymph node involvement in CTCL. T-cell clonality was determined by 2 independent polymerase chain reaction (PCR) assays, namely a recently developed T-cell receptor-beta (TCR-beta) PCR technique as well as an established TCR-gamma PCR. T-cell clonality was found in 22 of 22 lymph nodes with histologically detectable CTCL involvement as well as in 7 of 14 histologically noninvolved dermatopathic lymph nodes. The clonal T-cell populations in the lymph nodes were in all cases identical to those detected in the corresponding skin lesions, identifying them as the tumor cell population. T-cell clonality was not found in any of the 12 dermatopathic lymph nodes from 12 patients with inflammatory skin diseases. Clonal T-cell detection in 7 of 14 dermatopathic lymph nodes of patients with CTCL was associated with limited survival (74 months; confidence interval [CI], 66-82 months) as in patients with histologically confirmed lymph node involvement (41 months; CI, 35-47 months), whereas all patients without T-cell clonality in the lymph nodes (7 patients) were alive at the last follow-up. Thus, T-cell clonality analysis is an important adjunct in differentiating benign dermatopathic lymphadenitis from early CTCL involvement.

Long-term implications of T-cell receptor gene rearrangement analysis by Southern blot in patients with cutaneous T-cell lymphoma

BACKGROUND

T-cell clonality analysis by Southern blot (TSB) in skin biopsy specimens suggestive of mycosis fungoides may be helpful in confirming the diagnosis of a cutaneous lymphoma. However, there are no data available regarding the long-term prognostic implication of such results.

OBJECTIVES

We sought to determine the long-term prognostic significance of TSB results from skin biopsy specimens of patients with mycosis fungoides.

METHODS

We reviewed the records from the Cleveland Clinic Foundation and Northwestern University Medical Center for cases of biopsy-proven mycosis fungoides with results available for skin biopsy TSB from 1987 to 1990.

RESULTS

The detection of clonality by TSB correlates with a higher TNM stage (median stage for positive TSB, IIb vs negative TSB, Ib; P <.05), but not with age at presentation (62 vs 59 years) or duration of disease before presentation (6.2 vs 5.9 years). Although the long-term survival was not significantly different between the 2 groups, there was a trend for patients with positive TSB to die earlier (5-year survival of 67% vs 87%). Disease progression did not correlate with TSB results. Higher clonality rates were noted among patients with biopsy specimens showing a denser lymphoid infiltrate and a higher grade of cytologic atypia.

CONCLUSIONS

Detection of clonality with TSB requires a significant clonal burden. Although clonality can be detected in patients with patches and plaques (T1 and T2) most cases with positive results were obtained from patients with advanced disease (T3 and T4). In our experience, detection of clonality by TSB does not correlate with disease progression and does not carry long-term prognostic implications.

Update on erythrodermic cutaneous T-cell lymphoma: report of the International Society for Cutaneous Lymphomas

Two conferences were sponsored by the International Society for Cutaneous Lymphomas (ISCL) to gain consensus on definitions and terminology for clinical use in erythrodermic cutaneous T-cell lymphoma (E-CTCL). Three subsets of E-CTCL were defined: Sézary syndrome ("leukemic phase" E-CTCL), erythrodermic mycosis fungoides (secondary E-CTCL that develops in patients with mycosis fungoides), and E-CTCL, not otherwise defined. The hematologic criteria recommended for Sézary syndrome are intended to identify patients with a worse prognosis compared with the other E-CTCL subsets and consist of one or more of the following: (1) an absolute Sézary cell count of 1000 cells/mm3 or more; (2) a CD4/CD8 ratio of 10 or higher caused by an increase in circulating T cells and/or an aberrant loss or expression of pan-T cell markers by flow cytometry; (3) increased lymphocyte counts with evidence of a T-cell clone in the blood by the Southern blot or polymerase chain reaction technique; or (4) a chromosomally abnormal T-cell clone. For staging purposes, it is proposed that these criteria define the B2 blood rating and that the B2 rating be considered equivalent to nodal involvement.

Evidence that an identical T cell clone in skin and peripheral blood lymphocytes is an independent prognostic factor in primary cutaneous T cell lymphomas

The monoclonality of the T cell receptor gamma-chain gene was analyzed by polymerase chain reaction in skin and blood specimens of 85 patients with cutaneous T cell lymphomas including 67 mycosis fungoides, seven Sézary syndromes, and 11 CD30- nonepidermotropic cutaneous T cell lymphomas. A cutaneous T cell clone was detected in 69% of mycosis fungoides and 100% of Sézary syndromes. This frequency varied according to the clinical stage: 57% in early stages (Ia-IIa) to 96% in advanced stages (IIb-IV, Sézary syndrome). A peripheral blood T cell clone was detected in 42% of early stages and in 74% of late stages but was identical to the cutaneous one in 15% and in 63%, respectively. A significant association between initial clinical stage and T cell monoclonality was observed. In nonepidermotropic cutaneous T cell lymphomas, T cell monoclonality was detected in 55% of skin and 36% of blood samples. Univariate and multivariate analyses showed that, besides the initial clinical stage, an identical cutaneous and blood T cell clone was an independent prognostic factor for disease progression of mycosis fungoides/Sézary syndrome (hazard ratio 3.4, 95% confidence interval 1.4-9.9). Parallel polymerase chain reaction study of skin and blood specimens may therefore provide an initial prognostic marker that could help to monitor therapeutic strategies. A fully prospective study, with simultaneous therapeutic trials, needs to be done to confirm our findings and to include treatment variables in the statistical analysis.

A novel four-color PCR assay to assess T-cell receptor gamma gene rearrangements in lymphoproliferative lesions

We describe a novel 4-color polymerase chain reaction (PCR) assay combined with GeneScan analysis to assess for T-cell receptor gamma chain gene (TCRgamma) rearrangements and evaluate its usefulness in 86 lymphoproliferative lesions. In this assay, each variable region (Vgamma) family primer is 5' end-labeled with a different fluorescent dye, allowing determination of the Vgamma family involved in each TCRgamma rearrangement. PCR products were analyzed by capillary electrophoresis. We detected clonal TCRgamma rearrangements in 60 (98%) of 61 T-cell lymphomas, 2 (15%) of 13 B-cell lymphomas, and 3 (25%) of 12 reactive lesions. These results compared favorably with conventional PCR methods using denaturing gradient gel electrophoresis, which revealed clonal TCRgamma rearrangements in 37 (90%) of 41 T-cell lymphomas, 1 (25%) of 4 B-cell lymphomas, and 2 (25%) of 8 reactive lesions. This 4-color PCR assay is at least equivalent to conventional PCR methods and is convenient, allows accurate size determination of TCRgamma rearrangements, and identifies the specific Vgamma family involved, providing more specific information about TCRgamma rearrangement.

The value of clonality in the diagnosis and follow-up of patients with cutaneous T-cell infiltrates

The diagnosis of early stages of cutaneous T-cell lymphoma (CTCL) is often difficult, especially for lesions that are at the borderline between reactive and neoplastic skin T-cell infiltrates. T-cell monoclonality in these lesions is considered by some to be an important prognostic factor of neoplastic evolution, whereas others claim that clonality can also be found in benign skin infiltrates and is therefore of limited diagnostic value. To address this controversy, the authors analyzed retrospectively eight patients with lymphocytic skin lesions who progressed to CTCL, and three patients with recurrent T-cell lymphocytic infiltrates who had not developed CTCL. From a total of 65 biopsies of eight progressing patients, 32 were diagnosed as histologically malignant and 33 were diagnosed as benign or borderline. The authors found clonality by either polymerase chain reaction or Southern blot analysis in 88% of malignant and in 79% of nonmalignant lesions. None of the 37 biopsies of non-progressing patients was clonal. These results indicate strongly that the presence of monoclonality in T-cell skin infiltrates is related closely to the risk of developing CTCL. The value of clonality as a marker of malignancy is supported by the absence of T-cell clonal populations in all infiltrates from patients who had not progressed to lymphoma.

How useful are T-cell receptor gene rearrangement studies as an adjunct to the histopathologic diagnosis of mycosis fungoides?

The diagnosis and differential diagnosis of mycosis fungoides (MF) is often difficult, clinically and histologically. Recent attempts to enhance diagnostic sensitivity have involved T-cell receptor (TCR) gene rearrangement studies, using Southern blot or polymerase chain reaction (PCR) technique. PCR is more widely used because of its increased sensitivity, lower labor- and cost-intensive analytic steps, lack of radioactive substances, and applicability to routinely processed biopsies. Several studies that use this technique detect clonal bands in 50% to 83% of the MF specimens from patch, patch/plaque, and erythrodermic stages, which often pose a diagnostic challenge. This compares with no clonality in the control groups of most of these studies, or with up to 13% in a few studies, although long-term follow-up reveal that some cases of so-called "clonal dermatitis" eventually progress into overt cutaneous T-cell lymphoma. Furthermore, retrospective studies on archival histologic material from patients with MF demonstrate similar rates of clonality in histologically "inconclusive," "borderline," and diagnostic MF biopsies. Therefore, in the proper clinicopathologic setting, and with consideration of the known limitations of this technique, TCR gene rearrangement studies on lesional skin using PCR may be helpful as an adjunct to the histopathologic diagnosis of MF.

Demonstration of Frequent Occurrence of Clonal T Cells in the Peripheral Blood But Not in the Skin of Patients With Small Plaque Parapsoriasis

Clinical, immunohistological, and molecular biological data suggest the chronic dermatosis small plaque parapsoriasis (SPP) to be a precursor of mycosis fungoides (MF). However, most data are contradictory and confusing due to inexact definition of SPP. Recently, clonal T cells were detected in skin and blood samples of early MF. Because demonstration of identical T-cell clones in skin and blood of SPP patients would indicate a close relationship of SPP to MF, we investigated the clonality of skin and blood specimens from 14 well-defined SPP patients. By a polymerase chain reaction (PCR) amplifying T-cell receptor γ rearrangements and subsequent high-resolution electrophoresis, clonal T cells were detected in 9 of 14 initial and 32 of 49 follow-up blood samples, but in 0 of 14 initial skin specimens. Even a clone-specific PCR showing the persistence of the initial blood T-cell clone in 20 of 20 follow-up samples, failed to detect the T-cell clone in the skin. In 2 patients, the clonal T cells were shown to be CD4+. For the first time, the majority of SPP patients was shown to carry a T-cell clone in the peripheral blood. Although a relation between circulating clonal T cells and SPP cannot directly be proven by the applied techniques, our results indicate blood T-cell clonality to be a characteristic feature of SPP and CTCL because analysis of multiple controls and clinical workup of our SPP patients excluded other factors simulating or causing a clonal T-cell proliferation. A sufficient cutaneous antitumor response but also an extracutaneous origin of the T-cell clones might explain the failure to detect skin infiltrating clonal T cells.

Demonstration of Frequent Occurrence of Clonal T Cells in the Peripheral Blood But Not in the Skin of Patients With Small Plaque Parapsoriasis

Clinical, immunohistological, and molecular biological data suggest the chronic dermatosis small plaque parapsoriasis (SPP) to be a precursor of mycosis fungoides (MF). However, most data are contradictory and confusing due to inexact definition of SPP. Recently, clonal T cells were detected in skin and blood samples of early MF. Because demonstration of identical T-cell clones in skin and blood of SPP patients would indicate a close relationship of SPP to MF, we investigated the clonality of skin and blood specimens from 14 well-defined SPP patients. By a polymerase chain reaction (PCR) amplifying T-cell receptor γ rearrangements and subsequent high-resolution electrophoresis, clonal T cells were detected in 9 of 14 initial and 32 of 49 follow-up blood samples, but in 0 of 14 initial skin specimens. Even a clone-specific PCR showing the persistence of the initial blood T-cell clone in 20 of 20 follow-up samples, failed to detect the T-cell clone in the skin. In 2 patients, the clonal T cells were shown to be CD4+. For the first time, the majority of SPP patients was shown to carry a T-cell clone in the peripheral blood. Although a relation between circulating clonal T cells and SPP cannot directly be proven by the applied techniques, our results indicate blood T-cell clonality to be a characteristic feature of SPP and CTCL because analysis of multiple controls and clinical workup of our SPP patients excluded other factors simulating or causing a clonal T-cell proliferation. A sufficient cutaneous antitumor response but also an extracutaneous origin of the T-cell clones might explain the failure to detect skin infiltrating clonal T cells.

Immunophenotyping and T-cell receptor gamma gene rearrangement analysis as an adjunct to the histopathologic diagnosis of mycosis fungoides

BACKGROUND

The histopathologic diagnosis of mycosis fungoides (MF) may be difficult.

OBJECTIVE

Our purpose was to evaluate the role of immunophenotyping and T-cell receptor (TCR) gene rearrangement studies as an adjunct to the histopathologic diagnosis of MF.

METHODS

Immunohistochemical studies with antibodies to CD4, CD5, CD7, and CD8 and TCR gamma gene rearrangement analysis with a polymerase chain reaction were performed on fresh-frozen material of patients with "classic" histology of MF, "inconclusive" histology, and benign inflammatory dermatoses.

RESULTS

Clonal TCR gamma gene rearrangements were found in 11 of 16 (69%) of classic MF cases, in 3 of 19 (16%) of inconclusive cases, and in none of the 12 inflammatory dermatoses cases (P < .05 and P < .001, respectively). Only the mean CD7 counts were statistically significantly different between these 3 groups (MF < inconclusive < inflammatory).

CONCLUSION

Inconclusive histology is probably a heterogeneous group in which CD7 counts and TCR gamma gene rearrangement studies might help to differentiate the MF cases from the benign cases.

Differentiation between actinic reticuloid and cutaneous T cell lymphoma by T cell receptor gamma gene rearrangement analysis and immunophenotyping

AIMS

Differentiation between actinic reticuloid and cutaneous T cell lymphoma can be extremely difficult. Demonstration of clonal T cell receptor (TCR) gene rearrangements has been suggested as a potential diagnostic criterion, but the results obtained thus far have been conflicting. This study investigated whether TCR gamma gene rearrangement analysis, using polymerase chain reaction (PCR) in combination with denaturing gradient gel electrophoresis (DGGE) and immunohistochemistry, can serve as a diagnostic criterion.

METHODS

PCR/DGGE was performed on skin, peripheral blood mononuclear cells, and/or lymph nodes of seven patients with actinic reticuloid, 11 patients with Sézary syndrome, and 15 patients with a benign form of erythroderma. The results of PCR/DGGE and Southern blot analysis of TCR beta gene rearrangements were compared. In addition, CD4:CD8 ratios in skin and peripheral blood samples were investigated.

RESULTS

Clonal T cell populations were detected in 19 of 21 samples obtained from patients with Sézary syndrome but were not detected in any of the 12 samples from patients with actinic reticuloid. Clonal T cells were detected in the peripheral blood of only one of 15 patients with a benign form of erythroderma. PCR/DGGE and Southern blot analysis gave concordant results in 28 of 29 samples. Immunophenotypic analysis demonstrated increased proportions of CD8+ T cells in skin (seven of seven cases) and peripheral blood (four of seven cases) of patients with actinic reticuloid.

CONCLUSION

The results of this study demonstrate that gene rearrangement analysis, in combination with immunohistochemistry, may be an important adjunct in differentiating between actinic reticuloid and cutaneous T cell lymphoma. In patients suspected of having actinic reticuloid, application of both techniques is recommended.

The polymerase chain reaction in the diagnosis of early mycosis fungoides

The earliest or patch stage of mycosis fungoides may present diagnostic difficulty both clinically and pathologically. The present study of the polymerase chain reaction (PCR) as a diagnostic tool in early mycosis fungoides was therefore undertaken, using a rapid PCR method for the detection of gamma- and beta-chain T-cell receptor (TCR) gene rearrangements in routine formalin-fixed, paraffin-embedded histological sections. Forty-two biopsies were studied from 26 patients with mycosis fungoides. Twenty-three skin biopsies with a clinicopathological diagnosis of early, or patch stage, mycosis fungoides were investigated. Of these, 18 (78 per cent) showed TCR-gamma or both beta- and gamma-chain TCR gene rearrangements. TCR gene rearrangements were shown in seven of the 14 plaque stage lesions (50 per cent) and also in the single case of tumour stage disease. Where gene rearrangements were identified, these were identical in all biopsies from an individual patient, irrespective of the site of the lesion, the disease stage, or the time lapse between the biopsies. The PCR is therefore a highly sensitive technique, which can be performed on routine pathological material, in cases where the diagnosis of early mycosis fungoides cannot be made with certainty on conventional histopathological and immunohistochemical grounds.

Lymphomatoid papulosis and associated cutaneous lymphoproliferative disorders exhibit a common clonal origin

Determination of the clonal relationship among multiple lymphoproliferative disorders occurring in individual patients has been hampered by dependence on molecular biologic techniques that require analysis of advanced lesions containing high tumor clone densities to isolate dominant, clonal antigen-receptor gene rearrangements. Polymerase chain reaction/denaturing gradient gel electrophoresis (PCR/DGGE) involves the amplification of T-cell receptor (TCR)-gamma gene rearrangements followed by their electrophoresis in denaturing gradient gels. This method detects dominant TCR-gamma gene rearrangements at tumor clone densities as low as 0.1%, making this assay suitable for analysis of early as well as late lesions. Using this approach, we analyzed skin lesions of lymphomatoid papulosis and either CD30+ large-cell lymphoma or early patch/plaque mycosis fungoides that developed in three patients. In each case, the dual specimens exhibited an identical band pattern by PCR/DGGE analysis, suggesting a common clonal origin. To confirm this clonal relationship, the dominant TCR-gamma gene rearrangements were eluted, amplified, cloned, and sequenced. In each case, they showed identical junctional sequences. These findings are significant for several reasons: 1) they demonstrate the common clonal origin of lymphomatoid papulosis and CD30+ large-cell lymphoma or mycosis fungoides occurring in individual patients; 2) they confirm that co-migrating PCR/DGGE bands exhibit identical nucleotide sequences; and 3) they provide a method for determining the sequence of a tumor-derived TCR-gamma gene rearrangement in early lesions containing a low tumor clone density. This latter feature should allow the prospective molecular staging of early cutaneous lymphoproliferative disorders.

Expression of V beta gene segments by Sezary cells

The T-cell receptor V beta repertoire expressed by Sezary cells was determined in a series of 16 patients whose samples have been shown to contain a majority of tumor cells. By using anti-V beta monoclonal antibodies, polymerase chain reaction analysis of expressed V beta, and, in selected cases, nucleotide sequencing, we have shown that the expressed V beta segments belong to five V beta families (V beta 5, V beta 6, V beta 8, V beta 13, and V beta 18), which contain a large fraction of the T-cell receptor V beta repertoire and do not share significant similarities in complementary determining region 4. V beta segments from these five families were also found to be strongly expressed by CD4 + CD7- peripheral blood cells obtained by fluorescence-activated cell sorting from two healthy donors. The diversity of the V beta repertoire expressed by Sezary cells appears to be similar to that expressed by circulating non-neoplastic T cells. These data do not support the hypothesis that a common superantigen is involved in the initiation of this form of cutaneous T-cell lymphoma.

Hypopigmented variant of mycosis fungoides: demography, histopathology, and treatment of seven cases

BACKGROUND

Hypopigmented macules have been described infrequently as a presenting form of mycosis fungoides (MF).

OBJECTIVE

This study was designed to clarify general characteristics of a hypopigmented MF variant.

METHODS

Seven new cases were investigated with the use of descriptive epidemiology techniques. Demographic parameters, histopathology, and treatment outcomes were analyzed. These data were combined with those from prior reports to develop a broad composite view of this disease process.

RESULTS

The median ages in our series were 36 years for disease onset and 39 years at biopsy diagnosis. All patients had brown or black skin. Histologic findings consistently showed a lack of epidermal atrophy and moderate to profound exocytosis. Treatment with PUVA induced rapid and complete repigmentation in six of seven patients.

CONCLUSION

On the basis of our experience and a literature review, the hypopigmented variant of MF occurs in a younger population than typical forms of the disease and affects persons with dark skin almost exclusively. Microscopic features include lack of epidermal atrophy and moderate to extreme epidermotropism of infiltrating mononuclear cells. The treatment of choice appears to be PUVA.

Gene rearrangements and chromosomal translocations in T cell lymphoma--diagnostic applications and their limits

The diversity of the T cell receptor (TCR) repertoire is established for individual T lymphocytes by developmentally regulated gene rearrangements and shaped by predominantly intrathymic selection procedures. TCR gene probes in Southern blot experiments and TCR primers for the polymerase chain reaction (PCR) help to distinguish polyclonal from abnormal clonal T cell proliferations and to monitor clonal disease after treatment. Rearrangement studies can identify the lineage and developmental stage of a lymphocyte clone. Cross-lineage rearrangements, false positive or negative results are rarely misleading when morphology and immunophenotypical findings are considered. Rearrangement studies, however, have not contributed significantly to the comprehension of lymphomagenesis. Analyses of characteristic chromosomal translocations in T cell leukaemias and lymphomas may provide further insight into the mechanisms of malignant transformation. Transcription factors are often involved and sometimes abnormally transcribed, which may alter the physiological intracellular signalling in T cells. Interphase cytogenetic analysis by chromosomal fluorescence in situ hybridization (FISH) has become a new tool in the search for transformed T cells carrying specific translocations. Archival biopsy material is now accessible for PCR rearrangement studies and FISH cytogenetics. This adds another dimension to the diagnosis, disease monitoring and biological understanding of malignant T cell lymphomas and leukaemias.

Analyses of T-cell receptor beta-chain genes by Southern blotting in known and suspected cutaneous T-cell lymphoma. A study of 67 samples from 32 patients

In this study we have investigated the configuration of the T-cell receptor (TCR) beta-chain genes in benign cutaneous conditions (n = 5) and known (n = 22) or suspected (n = 5) cutaneous T-cell lymphoma (CTCL). Sequential biopsies from skin, lymph node, blood and/or bone marrow were available in 12 cases of the 22 confirmed CTCL, and a total of 67 samples were analysed. In the benign conditions, clonal rearrangements of the TCR beta-chain genes were seen in neither skin nor blood samples. In contrast, in CTCL clonal rearrangements were detected in all skin samples from plaque or tumour lesions of mycosis fungoides. Clonal TCR rearrangements were also present in skin and blood samples from two patients with Sèzary's syndrome, and in skin and blood samples from three of five patients with clinically suspected CTCL. In 10 patients with large cell lymphomas, clonal rearrangements were detected in skin samples in half of the cases. In the remaining patients, clonal TCR rearrangements could not be detected in the skin, but only in the blood and/or bone marrow specimens. Results from the analyses of sequential biopsies showed identical patterns of rearrangement in 11 patients. In the remaining patient, the pattern of rearrangement differed between skin and lymph node. These data confirm and extend previous reports and indicate that analysis of TCR beta-chain genes by Southern blotting forms a useful supplement to other methods for the diagnosis of known and suspected CTCL. They also emphasize the importance of studying not only skin, but also extracutaneous sites.

Localization of clonal T cells to the epidermis in cutaneous T-cell lymphoma

BACKGROUND

Mycosis fungoides (MF) is a form of cutaneous T-cell lymphoma (CTCL) characterized by progression of clonal, epidermotropic T cells with the proliferative (Ki-67+) T-cell fraction primarily confined to the epidermis in early CTCL.

OBJECTIVE

Our purpose was to determine whether the malignant clone (recognized by its clonal T-cell receptor [TCR] rearrangement) might also be localized to the epidermal compartment by differential Southern blot analysis.

METHODS

A rapid heat-saline technique was used to separately isolate epidermal and dermal DNA from 11 patients with CTCL (1 with disease in the pre-MF stage, 4 with patch-stage MF, 3 with plaque-stage MF, 1 with tumor-stage MF, 1 with Sézary syndrome, and 1 with non-MF peripheral T-cell lymphoma). Whole and heat-saline separated 6 mm biopsy specimens (obtained from the same lesion) were analyzed by standard Southern blotting with 5 to 10 micrograms of DNA digested with BamHI, HindIII, or EcoRI in each case. Filters were probed with a 32P-labeled TCR-C beta complementary DNA. Skin compartment localization of TCR-C beta rearrangement was compared with results of diagnostic immunophenotyping and expression of proliferating cell nuclear antigen.

RESULTS

DNA yields were as follows: from the whole specimens, 14.5 to 62.5 micrograms; from epidermal sheets, 2 to 42.5 micrograms; and from the dermis specimens, 2.5 to 25.5 micrograms. Whole and separated specimens from one patient with plaque-stage disease, three with patch-stage disease, and one patient with pre-MF disease revealed no rearrangement. Six patients had detectable gene rearrangements in the whole specimen by Southern blot; four of six had identical rearrangements in only the epidermal fragment (including the Sézary syndrome biopsy specimen) and not the dermis. The other two patients had only dermal TCR-C beta rearrangement. No relation was seen between immunophenotype or proliferating cell nuclear antigen expression and the localization of TCR-C beta rearrangements. However, the degree of epidermotropism significantly correlated with the presence of TCR-C beta rearrangements in the epidermal sheets.

CONCLUSION

This study demonstrates that the malignant clone in CTCL can be localized to the epidermal compartment in most cases in which a TCR rearrangement is detectable and that these clones are associated with epidermal proliferation of lymphocytes. This technique of differential epidermal versus dermal Southern analysis for TCR rearrangement may improve sensitivity by helping to distinguish reactive from malignant T-cell populations in future studies of the pathogenesis of CTCL.

Detection of clonal T-cell receptor gamma gene rearrangements in early mycosis fungoides/Sezary syndrome by polymerase chain reaction and denaturing gradient gel electrophoresis (PCR/DGGE)

We used a gene amplification strategy to analyze T-cell receptor (TCR) gene rearrangements in 185 specimens, including mycosis fungoides/Sezary syndrome (MF/SS), other cutaneous neoplasms, inflammatory dermatoses, reactive lymphoid tissues, and normal skin. Genomic DNA was extracted from lesional tissues and rearrangements of the TCR-gamma chain gene were amplified using the polymerase chain reaction (PCR) with primers specific for rearrangements involving V gamma 1-8 or V gamma 9 gene segments. The resulting PCR products were then separated according to their nucleotide sequence as well as size by denaturing gradient gel electrophoresis (DGGE). Dominant clonal TCR-gamma gene rearrangements were detected in 61 of 68 MF/SS cases by PCR/DGGE. This sensitivity of 90% compared to a sensitivity of only 59% when dominant clonality was sought in 17 of these same cases by Southern blot analysis of TCR-beta gene rearrangements. This difference in sensitivity was greatest in early, minimally infiltrated skin lesions. PCR/DGGE was also more sensitive than Southern blot analysis for detecting peripheral blood involvement in two cases of early MF. Among 12 additional specimens of suspected MF/SS, nine (75%) showed clonal TCR-gamma gene rearrangements by PCR/DGGE including six of eight cases with a previously confirmed diagnosis of MF/SS and three of four cases without prior known MF/SS. Among 105 non-MF/SS specimens, dominant TCR-gamma gene rearrangements were detected in only six cases (6%). Four were diagnosed as chronic dermatitis and two were diagnosed as cutaneous lymphoid hyperplasia. We conclude that the large majority of MF/SS cases, including patch phase disease, possess dominant clonal TCR-gamma gene rearrangements. PCR/DGGE is more sensitive than Southern blot analysis for detecting dominant clonality and staging disease in patients with a confirmed diagnosis of MF/SS. However, because PCR/DGGE is sensitive enough to detect dominant TCR-gamma gene rearrangements in a subset of patients with chronic dermatitis, it cannot be used as the sole criterion for establishing a diagnosis of T-cell lymphoma. As with other molecular biologic clonality assays, clinicopathologic correlation is essential. Nevertheless, the detection of dominant clonality in some cases of histologically nonspecific dermatitis allows the identification of a previously unrecognized subset of patients, i.e., those with "clonal dermatitis." It will be important to determine the long-term risk of MF/SS among these patients because our study indicated that MF/SS can sometimes present with lesions indistinguishable from clonal dermatitis.

Primary CD8+ lymphoepithelioid lymphoma of the skin

We describe an 82-year-old man with CD8+ lymphoepithelioid lymphoma localized to the skin. The skin lesion had been present for 18 years. Histologically there was a dense infiltrate that consisted of atypical lymphoid cells and large epithelioid cells, thereby resembling the so-called Lennert's lymphoma. Local radiotherapy proved effective in reducing the size of the tumor. To the best of our knowledge, this is the first report of primary lymphoepithelioid lymphoma of the skin.

Parapsoriasis en plaques: its potential for progression to malignant lymphoma

BACKGROUND

Parapsoriasis en plaques (large-plaque type) is a premalignant condition capable of developing into cutaneous T-cell lymphoma (CTCL). However, it is not known whether the early stage of CTCL can be distinguished from parapsoriasis en plaques.

OBJECTIVE

Our purpose was to determine whether parapsoriasis en plaques can develop into CTCL.

METHODS

The clinical appearance, histopathologic features, immunophenotype, DNA rearrangements, and clinical course were analyzed in 20 cases.

RESULTS

T-cell receptor beta-chain gene rearrangement was detected in four of the 20 cases. No clinical, histopathologic, or immunohistochemical differences were found between patients with and without gene rearrangement.

CONCLUSION

The early stage of CTCL cannot be differentiated from parapsoriasis en plaques by clinical features, histopathologic characteristics, or immunophenotype. Patients with parapsoriasis en plaques exhibit heterogeneous findings, which may include monoclonal proliferation. Patients with long-standing parapsoriasis-like lesions resistant to conventional treatment require careful monitoring for the possible development of cutaneous lymphoma.

Diagnostic and prognostic significance of clonal T-cell receptor beta gene rearrangements in lymph nodes of patients with mycosis fungoides

In this study, 25 involved and uninvolved lymph nodes from 22 patients with mycosis fungoides (MF) and seven dermatopathic lymph nodes from patients with benign skin disorders were studied for the presence of clonal T-cell receptor beta (TCR beta) gene rearrangements by Southern blot analysis. These results were correlated with the histological classification, follow-up data, and survival. The results of the histological classification and Southern blot analysis were concordant in 26 of 32 cases. Clonal TCR beta gene rearrangements were found in all six MF lymph nodes showing (partial) effacement of the normal lymph node architecture, but in none of the eight uninvolved dermatopathic MF lymph nodes and in none of the seven dermatopathic control lymph nodes. In addition, in 5 of 11 dermatopathic MF lymph nodes that were considered to have early involvement by MF at histological examination, clonal TCR beta gene rearrangements were detected. In the group of MF patients with dermatopathic lymphadenopathy, patients with detectable clonal T-cell populations had a significantly shorter survival than patients without such a population (P < 0.01). The results of this study indicate that within the group of dermatopathic MF lymph nodes, prognostically different groups can be distinguished and that TCR beta gene rearrangement analysis may be an important adjunct in the early diagnosis of lymph node involvement by MF.

T-cell receptor gene rearrangement studies as a diagnostic tool in lymphoproliferative skin diseases

The growth of our knowledge in T-cell biology, in particular the molecular biology of the T-cell receptor (TCR), has provided a means to molecularly characterize lymphoproliferative diseases of the skin based on the presence or absence of a clonal population of T lymphocytes. TCR gene rearrangement studies, by Southern blot analysis, have aided the investigative dermatologist in gaining insights into the pathogenesis and clonal evolution of lymphoproliferative skin diseases. In addition, the application of TCR gene rearrangement studies as a diagnostic aid in the evaluation of lymphoproliferative skin diseases has been introduced into clinical dermatology. Despite its enormous research value, TCR gene rearrangement studies presently have limited applications as an independent diagnostic tool. However, as our knowledge and experience grows and as the application of new techniques provides us with greater detection sensitivity and specificity, the diagnostic utility of TCR gene rearrangement studies will be enhanced.

Mycosis fungoides--type cutaneous T-cell lymphoma arising before 30 years of age. Immunophenotypic, immunogenotypic and clinicopathologic analysis of nine cases

BACKGROUND

Cutaneous T-cell lymphomas (CTCLs) rarely arise before 30 years of age; therefore the characteristics of these lymphomas are largely unknown.

OBJECTIVE

Our purpose was to assess the clinical and pathologic aspects of CTCL in young persons.

METHODS

We identified nine patients who had epidermotropic CTCL by 30 years of age and analyzed their lymphoma phenotypes and genotypes.

RESULTS

The diagnosis of CTCL was made an average of 6 years after the reported onset of the lesion. Histologic examination revealed the mycosis fungoides (MF) form of CTCL, and none of the patients underwent conversion to nonepidermotropic or large-cell variants of CTCL. The immunophenotypes were typical of MF-type CTCL; seven of eight lymphomas tested were predominantly CD4+ although in only three were abnormal CD4/CD8 ratios present. All four cases tested were CD7- (Leu-9-), and seven of eight specimens tested exhibited deficient Leu-8 expression. The loss of one or more pan-T-cell markers was found in four of eight patients tested. Clonal beta-chain T-cell receptor gene rearrangements occurred in skin samples from four of eight tested cases.

CONCLUSION

A persistent eruption, even in youths and young adults, should be thoroughly evaluated for possible CTCL.

T-cell receptor V beta-family usage in primary cutaneous and primary nodal T-cell non-Hodgkin's lymphomas

To evaluate whether the expression of T-cell receptor (TCR) V beta families in eight cases of malignant T-cell lymphomas took place in a preferential manner, we analyzed four cases of mycosis fungoides (MF), the most common form of primary cutaneous T-cell non-Hodgkin's lymphomas (NHL), and four cases of primary nodal T-cell NHL. The usage of V beta families in T-cell populations was investigated on mRNA that was transcribed to cDNA using a C beta primer and reverse transcriptase. Subsequently, the specific usage of the families was analyzed by polymerase chain reaction (PCR) using combinations of the selected C beta-oligonucleotide primer and one of the family-specific V beta primers. Peripheral blood lymphocytes from four healthy volunteers and 1 "reactive" lymph node served as a control and expressed all 20 V beta families tested for. In T-cell lines, with restricted V beta expression, and in three patients with advanced MF, only one or two V beta families were expressed at the mRNA level. In an early MF lesion this monoclonal expression was absent: several V beta families were expressed with a weak intensity. This may indicate either a polyclonal origin of MF, or that too few monoclonal neoplastic cells were present in the tissue specimen. In the four nodal T-cell NHL, only one family could be clearly distinguished, whereas some of the other V beta families showed only a weak expression. These latter families represent the reactive T-cell component in the nodal T-cell NHL. Both in nodal T-cell NHL and in MF there was no preferential expression of a particular V beta family. There was a good correlation between PCR data and the expression of V beta-family protein products observed by immunohistochemistry on tissue sections of the T-cell lymphomas. All T-cell lines, three cases of MF, and three cases of nodal T-cell NHL showed a rearrangement of the TCR beta chain on DNA level.

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.

Diagnostic value of T-cell receptor beta gene rearrangement analysis on peripheral blood lymphocytes of patients with erythroderma

Differentiation between Sézary's syndrome (SS) and benign forms of erythroderma may be extremely difficult. In this study T-cell receptor beta (TCR beta) gene rearrangement analysis was performed on peripheral blood lymphocytes (PBL) from 32 patients with erythroderma, including 10 patients with SS, three patients with another type of cutaneous T-cell lymphoma, and 19 patients with a benign form of erythroderma. The aim of this study was to define the sensitivity and specificity of this technique in the diagnosis of SS. Clonal TCR beta gene rearrangements were found in eight of 10 patients with SS, one T-CLL patient, one of two patients with erythrodermic mycosis fungoides, and only one of 19 patients from the benign group. In the two "false-negative" cases of SS clonal TCR beta gene rearrangements were detected in PBL obtained during follow-up. The results indicate that TCR beta gene rearrangement analysis on PBL is a sensitive and highly specific technique, that may contribute significantly to the differential diagnosis of patients with erythroderma. However, because both "false-positive" and "false-negative" results may occur, the results of gene-rearrangement analysis should always be considered in conjunction with clinical, histologic, and immunophenotypical data.

T-cell receptor gene rearrangement analysis: cutaneous T cell lymphoma, peripheral T cell lymphoma, and premalignant and benign cutaneous lymphoproliferative disorders

T-cell receptor gene rearrangement analysis is a useful technique to detect clonality and determine lineage of lymphoid neoplasms. We examined 103 patients with mycosis fungoides, Sézary syndrome, peripheral T cell lymphoma, potentially malignant lymphoproliferative disorders including pre-Sézary syndrome, large plaque parapsoriasis, lymphomatoid papulosis and follicular mucinosis, and various benign inflammatory infiltrates. A clonal rearrangement was detected in skin samples in 20 of 24 patients with mycosis fungoides and in peripheral blood samples in 19 of 21 patients with Sézary syndrome. A clonal population was also detected in seven of eight cases classified as peripheral T cell lymphoma. The potentially malignant dermatoses tended to have clonal rearrangement, with the exception of large plaque parapsoriasis, and further follow-up is needed to correlate clonality with the disease course. These studies demonstrate the value of molecular genetics as an adjunct to morphology in the examination of patients with cutaneous lymphoproliferative disease.

Analysis of beta, gamma, and delta T-cell receptor genes in mycosis fungoides and Sezary syndrome

The authors have analyzed the configuration of immunoglobulin (Ig) and beta, gamma and delta T-cell receptor (TCR) genes in DNA extracted from skin, lymph nodes, and peripheral blood mononuclear cells obtained from 41 patients with mycosis fungoides (MF), 14 patients with Sezary syndrome, and 13 patients with benign inflammatory dermatoses. No discrete rearranged bands (DRB) were detected in patients with inflammatory dermatoses. In tissue DNA from 19 patients with MF DRB were detected with beta and gamma, but not delta TCR probes. Only one patient with MF had a rearrangement of gamma and delta with germ line beta TCR genes. In 13 patients multiple biopsies were analyzed and DRB, when present, were identical in different lesions from individual patients. In three patients analysis of DNA from dermatopathic lymph nodes did not reveal DRB. Analysis of peripheral blood DNA from 24 patients revealed a discrete rearrangement of the gamma TCR gene in four patients and both beta and gamma genes in four additional patients. In MF DRB were detected more frequently with advancing stage of disease in tissues (P less than 0.01) but not in peripheral blood (P equals 0.36). Of 14 patients with Sezary syndrome, eight had DRB in peripheral blood DNA with both beta and gamma probes and in three of these patients identical DRB were also detected in DNA from skin biopsy samples. In contrast, DRB were not detected in the peripheral blood of the other six patients. In both MF and Sezary syndrome there was no restricted usage of particular V gamma genes. These results indicate that in MF (1) T-cell clones can be detected in skin biopsy specimens from the majority of patients with early stage disease, (2) gamma delta T-cell clones are only rarely found, and (3) TCR gene analysis can detect T-cell clones in the peripheral blood with a greater degree of specificity than conventional light microscopic study. In Sezary syndrome these studies also suggest that a subset of patients have a polyclonal population of circulating atypical lymphoid cells. In addition these patients appear to have a better prognosis than those with monoclonal disease.

Gene rearrangement analysis in lymphoid neoplasia

Current uses for gene rearrangement analysis in clinical dermatology are listed in Table 3. This technique is useful for determining the existence of clonal populations within a background of polyclonal lymphoid cells; therefore, it is helpful in the diagnosis and staging of patients with CTCL and PTCL. Although dual genotypes do occur, this technique is usually capable of determining lineage in a clonal lymphoid infiltrate and elucidating and characterizing the etiopathogenesis of certain neoplasms. On the basis of this review of the literature and our own experience, we conclude that gene rearrangement analysis shows great promise for monitoring response to therapy and detecting progression or relapse in patients with CTCL and PTCL. With the recent technology of PCR, it is possible to amplify specific sequences of DNA, detect molecular alterations in individual malignant T cells, and even identify exogenous retroviral gene sequences in tissues of patients with CTCL. Although gene rearrangement analysis has supported or established the clonal nature of lymphomatoid papulosis, pre-Sézary syndrome, granulomatous slack skin syndrome, and follicular mucinosis, the clinical significance of these findings is not yet clear. In the case of primary cutaneous B-cell lymphoma and its benign counterpart, B-cell pseudolymphoma, further investigation will be needed to determine the clinical significance of clonal rearrangements.

Antibodies against retroviral core proteins in relation to disease outcome in patients with mycosis fungoides

We have studied the relationship of antibodies reacting with human retroviral core proteins to the disease outcome in Finnish mycosis fungoides (MF) patients in a prospective manner. Antibodies recognizing human T-cell leukaemia/lymphoma virus I (HTLV-I) or human immunodeficiency virus type 1 (HIV-1) core proteins were found in 12 of 14 MF patients as shown by the Western blot method. The antibody reactivities showed three patterns: three patients had antibodies cross-reacting with the gag-encoded core proteins of both HTLV-I and HIV-1; seven patients showed antibodies reacting with HTLV-I core proteins only; and the sera of two patients reacted with HIV p24 core protein only. When following the clinical course of these patients, we found that the three patients with antibodies cross-reacting with both viruses had the most fulminant clinical course, and the overall duration of MF was, on average, 4 years less than in the rest of the patients. None of the patients, however, became leukaemic, or showed any other features suggestive of acute T-cell leukaemia/lymphoma (ATL). Two patients, who did not show anti-retroviral antibodies during the follow-up, had a stable disease with plaque-type skin lesions. Histological or immunohistological typing of the skin infiltrates did not correlate with the disease outcome or the above antibody patterns. Our results thus raise the possibility that an unknown retrovirus, immunologically related to the known human retroviruses, may be aetiologically linked to MF.

Mycosis fungoides and the Sézary syndrome: pathology, staging, and treatment

Mycosis fungoides and the Sézary syndrome are forms of cutaneous T-cell lymphoma. Mycosis fungoides is an uncommon disease: only about 500 new cases are diagnosed in the United States annually. The median age of onset is 55 years and there is a 2:1 male predominance. The etiology of mycosis fungoides is unknown. Although occupational exposures have been implicated, case control studies fail to support this hypothesis. Mycosis fungoides is typified by cutaneous plaques which may evolve into tumors over the course of time. It is often preceded by a lengthy pre-mycotic phase prior to the time of definitive diagnosis. In its earliest diagnostic phase, there may only be slightly scaling patches with a limited distribution. Indurated lesions evolve into plaques, which may become more generalized in their distribution. As the severity of skin involvement increases, there is an increasing likelihood of spread to extracutaneous sites. The pathology of this disease is marked by involvement of the epidermis (Pautrier microabscesses). Immunologic studies characterize these cells as belonging to the helper T-cell subset. Genotypic analysis demonstrates monoclonal rearrangements of the T-cell receptors of the infiltrating cells. The staging system for mycosis fungoides considers the extent of skin involvement, presence of lymph node or visceral disease, and detection of abnormal cells in the peripheral blood. Patients with disease limited to the skin (90% of newly diagnosed cases) are treated best with topical or cutaneous therapies. Common modalities include psoralen photochemotherapy (PUVA), topical chemotherapy (nitrogen mustard) and total skin electron beam therapy. Both topical nitrogen mustard and electron beam therapy have good initial response rates (73% and 100%) and may achieve long-term disease-free survival, especially in patients with initially limited disease. Even if the response is incomplete or relapse occurs, substantial and very important palliation is generally achieved with topical therapy. Recurrent or resistant cutaneous disease will require the use of sequential topical treatment. The median survival time of patients who present with disease limited to the skin is greater than 10 years, and many deaths in this group are from intercurrent causes, especially in patients with limited or generalized plaque disease. If cutaneous tumors are present, the majority of these patients will eventually die from disease-related causes. The prognosis of patients who develop extracutaneous disease is exceedingly poor (median survival time, approximately 1 year).(ABSTRACT TRUNCATED AT 400 WORDS)

T-cell receptor and immunoglobulin gene rearrangements in cutaneous T-cell-rich pseudolymphomas

T-cell rich, small lymphoid infiltrates of the skin may cause considerable problems in the differential diagnosis of reactive versus neoplastic lymphoproliferations, particularly when they lack the morphologic and immunophenotypical criteria for a malignant lymphoma. We did histologic, immunohistologic, and gene rearrangement studies on 10 biopsies from patients with persistent nodular T-cell-rich skin lesions refractory to topical therapy. Based on clinical and immunohistochemical findings, no discrimination was possible between reactive lesions and malignant lymphoproliferations. Histologically, most of the cases contained T-lymphocytic infiltrations that were assumed to be reactive; however, in four biopsies a neoplastic infiltration could not be excluded. Although the T-cell receptor (TCR) beta chain and the immunoglobulin heavy chain (IgH) genes were in germ-line configuration in nine of 10 cases, indicating a predominantly polyclonal lymphocellular infiltrate, in one patient without clinical evidence of malignant lymphoma at presentation a clonally rearranged TCR beta chain gene with the IgH gene in germ-line configuration was detected. One year later, the patient developed a cutaneous pleomorphic T-cell lymphoma and subsequently a large cell anaplastic (CD30+) T-cell lymphoma in an inguinal lymph node. We conclude that clonal T-cell proliferations can be detected by molecular genetic analysis of T-cell-rich, small lymphoid infiltrates of the skin. This finding may precede development of an overt malignant T-cell lymphoma.

Mycosis fungoides in children and adolescents

The clinical and histologic findings in five young patients with mycosis fungoides are reviewed. The skin specimen from a 16-year-old boy had an infiltrate predominantly Leu-1+, Leu-4+, Leu-3a + 3b+, OKT6+, Leu-2a-, Leu-8-, and Leu-9-, and rearrangements were noted in T cell receptor gene (beta chain [constant region probe] and gamma chain [J region probe]); no rearrangements were found in a histologically normal lymph node or peripheral blood. The skin specimen from an 11-year-old girl contained predominantly Leu-4+ and Leu-9+ lymphoid cells. No T cell receptor gene rearrangements were found in the skin or in an involved lymph node. The variations in clinical, histologic, and immunopathologic features suggest that mycosis fungoides in young patients represents a heterogeneous subgroup of cutaneous T cell lymphoma.

Cutaneous T cell lymphoma with suppressor/cytotoxic (CD8) phenotype: identification of rapidly progressive and chronic subtypes

We identified nine patients with cutaneous T cell lymphoma in whom the neoplastic cells expressed the CD8 (T8) suppressor T cell phenotype instead of the more common CD4 (T4) helper T cell phenotype. Five had rapidly progressive disease characterized by distinctive papulonodular skin lesions (four patients), involvement of palms or soles (four patients) or oral cavity (two patients), and poor response to standard topical therapy (four patients). Histologic examination showed extensive epidermotropism often associated with pagetoid features. Immunoperoxidase studies revealed a novel aberrant T cell phenotype characterized by lack of expression of CD4 and CD2 (T11) but positive staining for CD3 (T3) and CD7 (3A1). In contrast, the neoplastic cells from four patients with clinically more chronic CD8+ cutaneous T cell lymphoma, although also commonly epidermotropic, had a different aberrant T cell phenotype similar to that often seen in CD4+ mycosis fungoides; that is, there was lack of expression of CD7 but a positive reaction to staining for CD2. In two cases the tumor cells acquired the CD7 antigen or lost the CD2 antigen with progression of the disease. Two cases were analyzed with Southern blotting and both showed rearranged DNA bands that confirmed the presence of clonal populations of T cells. Our findings suggest the following: (1) CD8+ cutaneous T cell lymphoma can be rapidly progressive or chronic. (2) These two types cannot be reliably distinguished by histologic features. (3) Rapid progression was associated with a CD2-, CD7+ phenotype whereas chronicity was associated with a CD2+, CD7- phenotype.

Phenotypic and functional characterization of tumor infiltrating lymphocytes in mycosis fungoides: continuous growth of CD4+ CD45R+ T-cell clones with suppressor-inducer activity

Tumor-infiltrating lymphocytes (TIL) were obtained by mechanical release from a solitary rapidly grown tumor of a patient with mycosis fungoides. The preparations separated by density gradient centrifugation contained a major portion of CD3+ CD8+ WT31+ CD5- large T-cell blasts and a minor portion of non-blastic TIL predominantly of the CD3+ CD4+ phenotype. Using cDNA-probes for the constant region of the T-cell receptor beta-genes, the large cell fraction was identified as tumor by its distinct monoclonal rearrangement. TIL were expanded by culture in recombinant interleukin 2 and cloned by limiting dilution. Phenotypic analysis of expanded TIL and two clones further analyzed in more detail showed CD3+, CD4+, CD8-, and 2H4+ (CD45R+) expression. Cloned and uncloned TIL showed no NK and LAK activity, no proliferative response, and no cytotoxic activity against autologous tumor cells. These cells were unable to suppress the proliferative response of alloreactive T-cell clones stimulated by B-lymphoblastoid cell lines (i.e., they had no suppressor-effector activity), but strongly suppressed proliferation responses in allogeneic mixed lymphocyte culture (i.e., they most likely had suppressor-inducer activity). This was not the case when irradiated tumor cells were added. The present results demonstrate continuous in vitro growth of CD4+ and 2H4+ T-cell clones with suppressor-inducer activity obtained from TIL, and indicate that a subpopulation of TIL may down-regulate immune responses which may lead to suppression of antitumor immunity.

Differentiation between lymphomas and pseudolymphomas of the skin by computerized DNA-image cytometry

The histologic and immunohistologic differential diagnosis between pseudolymphomas (PL) and malignant lymphomas (ML) of the skin can be difficult. Since DNA cytometry has been found to be of both diagnostic and prognostic value in various neoplasms, its ability to discriminate between ML and PL in Feulgen-stained imprints of 17 PL and 49 ML skin biopsies was examined by high-resolution image analysis. The reliability of the following algorithms of DNA distribution was evaluated: 1) 2cDI (2c-deviation index), which reflects the variation of the nuclear DNA values around the diploid DNA peak; 2) percentage of cells having a DNA value greater than or equal to 5c (5cER; 5c-exceeding rate); 3) percentage of cells presenting with a DNA value greater than or equal to 4c (4cER). A 2cDI of 0.1 was found to be the most reliable marker for the differentiation between PL and ML. On the basis of this feature, 16 of 17 cases of PL and 46 of 49 cases of ML were correctly classified. The sensitivity, specificity, and efficiency of this feature were 94%. A 5cER greater than or equal to 1% had a specificity of 100%, but the sensitivity was only 43%. For the 4cER, a sensitivity of 61% and a specificity of 94% were found. In conclusion, the calculation of the 2cDI and the 5cER based on high-resolution image analysis provided additional helpful diagnostic features, and therefore should be included as a diagnostic tool. If the 5cER is at least 1%, the diagnosis of a ML can be confirmed with a specificity of 100%.

Malignant lymphomas of true histiocytic origin. A clinical, histological, immunophenotypic and genotypic study

The clinical, histological, immunophenotypic and genotypic properties of four cases of lymphoma of true histiocytic origin are described. The cases were identified by typing 925 non-Hodgkin's lymphomas by immunophenotypic and/or genotypic techniques, and they all presented with skin lesions. The histological and immunophenotypic examination showed dense, diffuse infiltrates of markedly pleomorphic mononuclear cells that were positive for macrophage-associated markers, and negative for B-cell, T-cell and myeloid cell-associated antigens. Staining for Ki-1 and epithelial membrane antigen was also negative. Gene rearrangements studies were performed in three cases, and all of these showed germline configuration of both T-cell receptor and immunoglobulin genes. In all cases, the clinical course was aggressive with rapid and widespread dissemination to internal organs, poor response to conventional chemotherapy, and short survival times (0.5 to 14 months). This suggests that although true histiocytic tumours are very rare, their recognition may be important for clinical and/or prognostic reasons.