Absence of BRAF mutations in UV-protected mucosal melanomas.

BACKGROUND: Mutations in BRAF have recently been identified in a significant percentage of primary and metastatic cutaneous malignant melanomas. As ultraviolet (UV) exposure may play a role in the development of cutaneous melanoma lesions with BRAF mutations, BRAF mutation frequency in melanomas arising in sites protected from sun exposure may be lower than those from sun-exposed areas. Thus, we determined the BRAF mutation frequency in a panel of 13 mucosal melanomas and compared those data with data from all currently published series of cutaneous melanomas. METHODS: BRAF exon 15 DNA from 13 archival primary mucosal melanomas (eight vulvar, four anorectal, and one laryngeal) was sequenced using intron-based primers. As archival DNA occasionally produces poor-quality template, results were confirmed with a TspRI restriction fragment length polymorphism (RFLP) that distinguishes wild-type BRAF from the common mutant form V599E. A binomial test was used to compare the mutation frequency in the mucosal melanomas with the published mutation frequency in cutaneous melanomas. RESULTS: None of the 13 mucosal melanomas in this series had an exon 15 BRAF mutation, as compared to 54/165 (33%) primary cutaneous melanomas with BRAF mutations in a compilation of all current published studies (p = 0.006). DISCUSSION: These data suggest that UV exposure, plays a role in the genesis of BRAF mutations in cutaneous melanoma, despite the absence of the characteristic C>T or CC>TT mutation signature associated with UV exposure, and suggests mechanisms other than pyrimidine dimer formation are important in UV-induced mutagenesis.

Identification of clonal T cells in the blood of patients with systemic sclerosis: positive correlation with response to photopheresis.

OBJECTIVES: To search for circulating clonal T-cell populations in patients with systemic sclerosis (SSc), and to determine whether T-cell clonality in the blood predicts therapeutic response to photopheresis. DESIGN: Analysis of clonal T-cell receptor gamma gene rearrangements before photopheresis treatment and blinded clinical evaluation of cutaneous response to photopheresis in a case series. SETTING: University hospital setting. PATIENTS: Thirteen consecutive patients with SSc. INTERVENTIONS: Photopheresis in 11 patients. MAIN OUTCOME MEASURES: Clonality of T cells in the blood before photopheresis and clinical response to photopheresis. RESULTS: Screening of blood samples from 13 SSc patients for clonal T-cell receptor gamma gene rearrangements revealed a monoclonal T cell population in 6 (46%) of 13 SSc patients. Clinical response to photopheresis in 11 patients was evaluated in a blinded manner using skin severity scores. Clonality of T cells appeared to be associated with a higher chance of response to photopheresis therapy, as 4 (67%) of 6 patients in the clone-positive group vs 1 (20%) of 5 in the clone-negative group experienced a clinically significant response to treatment. CONCLUSIONS: A high proportion of patients with SSc have detectable expanded clonal T-cell populations in the peripheral blood, and such patients appear more likely to respond to photopheresis.

Variable CD7 expression on T cells in the leukemic phase of cutaneous T cell lymphoma (Sézary syndrome).

CD7, a molecule normally expressed on 90% of normal CD4+ T cells, is often deficient on the malignant T cells of cutaneous T cell lymphoma. To investigate the clinical and biologic implications of CD7 expression, blood lymphocytes from 42 patients with the leukemic phase of cutaneous T cell lymphoma (CD4/CD8 ratio of 10 or more with evidence of a T cell clone in the blood) were analyzed for level of expression of CD7 by flow cytometry. CD7 expression by cells did not clearly segregate into two distinct subgroups that are either CD7 positive or CD7 negative as generally thought; however, nine of 17 patients with a predominantly CD4+CD7+ tumor population on early studies became CD4+CD7- over time whereas the converse situation was not observed. In addition, of three patients with evidence of large tumor cells in the blood coexisting with smaller cells, discordant CD7 expression was observed in one instance. In lymph node specimens, the percentage of cells expressing CD7 and other T cell markers did not correlate with histologic evidence of involvement. CD7 expression on blood lymphocytes also did not correlate with patients' survival nor to serum IgE levels or blood eosinophil counts, a finding suggesting that this marker does not identify functional cell subsets that produce serum interleukin-4 or -5, respectively. We speculate that the level of CD7 expression on malignant T cells may be the effect of sustained antigen stimulation in vivo analogous to what has been proposed to occur with normal T cells during aging.

Detection of clonal T-cell receptor gamma gene rearrangements using fluorescent-based PCR and automated high-resolution capillary electrophoresis.

BACKGROUND: Analysis of T-cell receptor gamma (TCR gamma) gene rearrangements by PCR is a powerful tool for detecting clonal T-cell populations for the diagnosis of lymphoid neoplasms. We report a method for TCR gamma PCR analysis using capillary electrophoresis (CE). METHODS AND RESULTS: To define the threshold for identification of a predominant monoclonal population within a polyclonal background, we developed a novel objective parameter of the peak height ratio (Rn) of the peak of interest and the average of the two immediate flanking peaks. After evaluation of monoclonal, reactive, and normal T-cell populations, an Rn of 3.0 or greater was determined to be consistent with a monoclonal population, whereas an Rn between 1.9 and 3.0 was considered an intermediate range. This CE method was compared with the standard denaturing gradient gel electrophoresis (DGGE) method using previously evaluated clinical specimens. Eleven of 12 clinical specimens (92%) with a definitive diagnosis of T-cell lymphoma were monoclonal by CE, with 100% concordance with the DGGE method. Of nine specimens morphologically suspicious for T-cell lymphoma, five specimens were positive by CE analysis compared with four specimens by DGGE. In addition, 14 specimens for staging from patients with known T-cell lymphoma were studied using both the CE and DGGE methods, with a concordance of 86%. CONCLUSION: CE is a powerful and efficient method for analysis of clonality by TCR gamma PCR.

Complete molecular remission during biologic response modifier therapy for Sézary syndrome is associated with enhanced helper T type 1 cytokine production and natural killer cell activity.

BACKGROUND: Cutaneous T-cell lymphoma (CTCL) is a clonally derived, skin-invasive malignancy of CD4(+) T lymphocytes with the phenotype of mature helper T cells. Advancing stages of CTCL are associated with depressed cell-mediated immunity, increased production of T helper type 2 cytokines and decreased levels of T helper type 1 cytokines. OBJECTIVE: Our purpose was to evaluate the cytokine secretion pattern and cell-mediated cytotoxicity in peripheral blood mononuclear cells of patients with Sézary syndrome in relation to the presence of the malignant clone. METHODS: Serial polymerase chain reaction for the T-cell receptor-beta or T-cell receptor-gamma gene rearrangement was used to determine the presence of the malignant clone. Enzyme-linked immunosorbent assays were used to determine the levels of interleukin 4 and interferon gamma produced by the peripheral blood mononuclear cells from the patients with Sézary syndrome. RESULTS: We demonstrate 3 cases of Sézary syndrome with typically suppressed cell-mediated cytotoxicity, elevated production of interleukin 4, and depressed production of interferon gamma by their peripheral blood mononuclear cells before institution of therapy with biologic response modifier therapy. In all 3 cases after clinical and molecular remission, we observed striking immunologic changes, including an increase in levels of natural killer cell activity and interferon gamma production and decreased production of interleukin 4. CONCLUSIONS: The observation that the cytokine secretion pattern by peripheral blood mononuclear cells from 3 patients with Sézary syndrome normalized with the disappearance of the malignant clone from the peripheral blood suggests that the malignant T cells account for the aberrant cytokine production. Moreover, the aberrant cytokine production may be the cause for suppression of cell-mediated immunity seen in advancing stages of CTCL.

Locally recurrent malignant melanoma characteristics and outcomes: a single-institution study.

Despite improvements in the identification and treatment of melanoma, local recurrence continues to challenge the success of current melanoma therapy. A retrospective analysis of 1,996 patients presenting from 1990 to 1997 at the Pigmented Lesion Group of the University of Pennsylvania was performed to assess clinical characteristics and outcomes of locally recurrent melanoma. The cases were analyzed by chart and pathological slide review. A control group was identified for statistical comparison. The incidence of locally recurrent melanoma during the study period was 2.2%. Lentigo maligna melanoma (LMM) accounted for 37% of the local recurrences. Increased tumor thickness and microsatellites were associated with "early" local recurrence and decreased survival from time of recurrence. Nineteen percent of the local recurrences occurred more than 5 years after the initial definitive treatment. The preponderance of locally recurrent LMM suggests the need for refinements in the techniques of margin identification and surgical excision of LMM. Tumors with increased thickness and microsatellites should receive particularly close attention. Lastly, with nearly 20% of the local recurrences occurring more than 5 years after the initial date of treatment, the authors suggest extending the follow-up time for all melanoma lesions beyond 5 years.

Sarcoidal tissue reaction in Sézary syndrome.

Sézary syndrome (SS) is an erythrodermic and leukemic variant of cutaneous T-cell lymphoma (CTCL). Occasionally, the histology of CTCL exhibits evidence of a granulomatous infiltrate in the skin. A case of SS that showed epithelioid granulomas resembling sarcoidosis in the skin and lymph nodes is presented. The clinical course of this patient has been relatively indolent.

Quantitative comparison of cytokine mRNA and inflammatory responses in cutaneous late phase allergic reactions.

UNLABELLED: The aim of this study was to quantitatively compare expression of mRNA for IL-5 and IFN-gamma with the frequency of mRNA-positive cells, total and activated eosinophils, neutrophils, lymphocytes, and vessels expressing adhesion molecules. Replicate biopsies of skin LPR to pollen antigens (Ag) and control injection sites (B) at 6 and 24 h were assessed for: (1) mRNA for IL-5 and IFN-gamma by quantitative RT-PCR (QC-RT/PCR); (2) frequency of cells expressing mRNA for IL-5 and IFN-gamma by in situ hybridization (ISH); (3) inflammatory cells and adhesion molecule expression. More mRNA for IL-5 was found in Ag- than in B-injected sites at 6 and 24 h by both QC-RT/PCR and ISH. Small amounts of mRNA for IFN-gamma were detected in Ag sites by QC-RT/PCR at 6 and 24 h, but were not significantly different than at B sites. The frequency of IFN-gamma mRNA(+)cells was higher in Ag than in B sites at 6 h. There was no correlation between the amount if IL-5 detected by QC-RT/PCR and frequency of IL-5 mRNA(+)cells by ISH. These findings also did not correlate with the degree of inflammatory responses. IN CONCLUSION: (1) greater IL-5 than IFN-gamma deposition in Ag sites suggests Th(2)predominance in LPR; (2) lack of correlation between QC-RT/PCR and ISH findings may reflect varying mRNA content of inflammatory cells.

Fine-needle aspiration biopsy in the evaluation of lymphadenopathy associated with cutaneous T-cell lymphoma (mycosis fungoides/Sézary syndrome).

We studied the role of fine-needle aspiration (FNA) in the evaluation of lymphadenopathy associated with cutaneous T-cell lymphoma (CTCL) in 11 patients with lymphadenopathy and compared findings with corresponding histologic material. Molecular genetic analysis for T-cell clonality by polymerase chain reaction (PCR) was performed on all aspirates. Immunophenotyping was successful in 4 of 7 cases in which flow cytometry was attempted from the aspirated material. Cytologic evaluation of FNA samples correlated strongly with histologic rating of involvement based on numbers of atypical cerebriform lymphocytes in the nodal specimen. Of 7 nodal specimens with scattered or small groups of atypical cells in the background of dermatopathic lymphadenopathy (LN1-2), the cytologic diagnosis was interpreted as reactive in all instances. Of 4 specimens with highly suspect (LN3) or definite histologic involvement (LN4), the cytologic diagnosis was likewise suspect or malignant. The correlation between molecular genetic studies on FNA samples and studies on tissue was not significant; in 2 cases, a T-cell clone was detected in the nodal tissue sample but not in the FNA sample, suggesting undersampling. A T-cell clone was detected by PCR in 5 of 7 nodal specimens judged reactive by FNA biopsy or histologic assessment. FNA for cytologic and molecular genetic analysis is a useful method to evaluate lymphadenopathy associated with CTCL and may obviate the need for surgical biopsy.

Mycosis fungoides with CD30-positive cells in the epidermis.

Large numbers of CD30-positive tumor cells are not typically observed in mycosis fungoides (MF), but CD30 expression may occur on large cells of MF that have transformed into high-grade large cell lymphoma. Of 202 patch/plaque phase MF cases studied by immunohistochemistry, we encountered 4 patients with patch-phase MF at stage Ia or Ib, whose lesions contained a high proportion (greater than 50%) of CD30-positive tumor cells within the epidermis. The morphologic and immunohistochemical features of these four cases were otherwise similar to those of other patch-phase MF cases, and were different from those of pagetoid reticulosis. More importantly, the clinical behavior of these cases did not differ from that of other cases of early MF without CD30 expression. The mechanism underlying the high levels of CD30 expression by epidermotropic tumor cells is unknown. With increased use of the CD30 immunohistochemical stain in the diagnosis of cutaneous lymphomas, similar cases are likely to be encountered, and perhaps will be evaluated for their clinical behavior.

Photopheresis: clinical applications and mechanism of action.

Photopheresis is a leukapheresis-based therapy that utilizes 8-methoxypsoralen and ultraviolet A irradiation. Photopheresis is currently available at approximately 150 medical centers worldwide. Recent evidence suggests that this therapy used as a single agent may significantly prolong life, as well as induce a 50%-75% response rate among individuals with advanced cutaneous T cell lymphoma (CTCL). Furthermore, a 20%-25% complete response rate with photopheresis alone, or in combination with other biologic response modifiers, has been obtained at our institution among patients with Sezary syndrome. These complete responses have been characterized by the complete disappearance of morphologically atypical cells from the skin and blood. The use of sensitive molecular techniques has also confirmed the sustained disappearance of the malignant T cell clone from the blood of patients with complete responses. In addition to the treatment of CTCL, numerous reports indicate that photopheresis is a potent agent in the therapy of acute allograft rejection among cardiac, lung, and renal transplant recipients. Chronic graft versus host disease also appears to be quite responsive to photopheresis therapy. Likewise, there may also be a potential role for photopheresis in the therapy of certain autoimmune diseases that are poorly responsive to conventional therapy. The immunologic basis for the responses of patients with these conditions is likely due to the induction of anticlonotypic immunity directed against pathogenic clones of T lymphocytes. Treatment-induced apoptotic death of pathogenic T cells and activation of antigen presenting cells are postulated to have important effects in this therapeutic process.

Interleukin-12 therapy of cutaneous T-cell lymphoma induces lesion regression and cytotoxic T-cell responses.

Progression of cutaneous T-cell lymphoma (CTCL) is associated with profound defects in cell-mediated immunity and depressed production of cytokines, which support cell-mediated immunity. Because we have observed marked defects in interleukin-12 (IL-12) production in CTCL and because IL-12 is critical for antitumor cytotoxic T-cell responses, we initiated a phase I dose escalation trial with recombinant human IL-12 (rhIL-12) where patients received either 50, 100, or 300 ng/kg rhIL-12 twice weekly subcutaneously or intralesionally for up to 24 weeks. Ten patients were entered: 5 with extensive plaque, 3 with Sezary syndrome, and 2 with extensive tumors with large cell transformation. One patient with Sezary syndrome dropped out after 1 week for personal reasons. Subcutaneous dosing resulted in complete responses (CR) in 2 of 5 plaque and partial responses (PR) in 2 of 5 plaque, and 1 of 2 Sezary syndrome (overall response rate CR+PR 5 of 9, 56%). A minor response also occurred in 1 of 5 plaque patients. Intralesional dosing resulted in individual tumor regression in 2 of 2 patients. Biopsy of regressing lesions showed a significant decrease in the density of the infiltrate in all cases and complete resolution of the infiltrate among those with clinical lesion resolution. An increase in numbers of CD8-positive and/or TIA-1-positive T cells were observed on immunohistochemical analysis of skin biopsy specimens obtained from regressing skin lesions. Adverse effects of rhIL-12 on this regimen were minor and limited and included low-grade fever and headache. One patient discontinued rhIL-12 at week 6 because of depression. These results suggest that rhIL-12 may augment antitumor cytotoxic T-cell responses and may represent a potent and well-tolerated therapeutic agent for CTCL.

Differences in phosphorylation of the IL-2R associated JAK/STAT proteins between HTLV-I(+), IL-2-independent and IL-2-dependent cell lines and uncultured leukemic cells from patients with adult T-cell lymphoma/leukemia.

To determine activation status of the IL-2R-associated (Jak/STAT) pathway in the HTLV-I infected cells, we examined tyrosine phosphorylation of Jak3, STAT3, and STAT5 in several HTLV-I(+) T-cell lines and in uncultured leukemic T cells isolated from patients with adult T-cell lymphoma/leukemia (ATLL). Constitutive basal phosphorylation of Jak3 and, usually, STAT3 and STAT5 was detected in all four IL-2-independent cell lines tested, but in none of the three IL-2-dependent cell lines. Similarly, there was no detectable basal phosphorylation of Jak3 and STAT5 in the leukemic cells from ATLL patients (0/8 and 0/3, respectively). However, stimulation with IL-2 resulted in Jak3 and STAT5 phosphorylation in both leukemic ATLL cells and IL-2-dependent lines. Furthermore, expression of SHP-1 phosphatase which is a negative regulator of cytokine receptor signaling, was lost in most IL-2 independent cell lines (3/4) but not in the leukemic ATLL cells (0/3). Finally, the HTLV-I(+) T-cell lines (313) but not the control, HTLV-I(-) T-cell lines were resistant to rapamycin and its novel analog RAD. We conclude that (1) HTLV-I infection per se does not result in a constitutive phosphorylation of the Jak3, STAT3, and STAT5 proteins; (2) malignant transformation in at least some cases of ATLL does not require the constitutive, but may require IL-2-induced, activation of the IL-2R Jak/STAT pathway; and (3) there are major differences in T-cell immortalization mechanism(s) which appear to involve SHP-1 and target molecules for rapamycin and RAD.

Quantitative analysis of T-cell receptor beta variable-gene usage in cutaneous late-phase reactions: implications for T-lymphocyte recruitment in cutaneous inflammation.

To determine if functionally distinct T-lymphocyte (T cell) subsets accumulate in late-phase immunoglobulin E-mediated reactions (LPR), we quantitatively analyzed the immunophenotype and the T-cell receptor beta variable-gene (Vbeta) repertoire of T cells in cutaneous LPR. Peripheral blood and skin biopsies were obtained 6 or 24 h after sensitive subjects were challenged with intradermal injections of grass pollen allergen (Ag) and control (C) solution. The frequency of cells expressing CD3, CD4, CD8, CD45RO, and CD25/mm2 was determined by immunohistochemistry in nine subjects. Vbeta usage was assessed by reverse transcription-PCR in five of nine subjects. A significantly greater frequency of CD3(+) and CD45RO+ (memory) T cells was detected in Ag sites than in C sites at 24 h after challenge but not at 6 h. The frequency of activated (CD25(+)) and helper (CD4(+)) T cells appeared to be increased in Ag sites as well, though not significantly. Vbeta6 was the most commonly expressed Vbeta detected in Ag sites, but it was also detected in accompanying C sites. Vbeta2 was the most commonly expressed Vbeta detected in C sites. Sequence analysis in one case revealed Vbeta expression in a 6-h Ag site to be essentially polyclonal. Our findings suggest that memory T cells with Vbeta expression similar to that in normal skin accumulate in developing cutaneous LPR. The limited usage of Vbeta suggests a preferential recruitment or retention of reactive T cells from an endogenous subset of skin-homing T cells with its own skewed Vbeta repertoire.

Subcutaneous panniculitis-like T-cell lymphoma: clinicopathologic, immunophenotypic, and genotypic analysis of alpha/beta and gamma/delta subtypes.

Subcutaneous panniculitis-like T-cell lymphoma (SPTCL) is an uncommon cutaneous lymphoma that has been proposed as a distinct clinicopathologic entity, but studies of SPTCL are limited. We studied the clinicopathologic, immunophenotypic, and genetic features of 11 SPTCLs. All cases had a variable admixture of pleomorphic small, medium, or large lymphocytes and histiocytes infiltrating the subcutis in a lobular panniculitis-like pattern. A granulomatous reaction was seen in three cases and erythrophagocytosis in four. Karyorrhexis and fat necrosis were present in all cases. Angioinvasion was seen in seven SPTCLs; four had areas of coagulation necrosis. All cases expressed T-cell-associated antigens (CD3epsilon, CD45RO, or CD43) and T-cell receptors (TCR); nine expressed alphabeta TCRs and two expressed gammadelta TCRs. T-cell receptor-gamma, TCRbeta, or TCRdelta genes were clonally rearranged in 8 of 10 cases studied. Both gammadelta SPTCLs expressed Vdelta2+ TCRs and were CD4-, CD8- and CD56+. CD56 was negative in seven of nine alphabeta SPTCLs and inconclusive in the other two. Six of nine alphabeta SPTCLs were CD8+; the CD4/CD8 phenotypes were indeterminate in the other three. Cytolytic granule-associated proteins were expressed by all SPTCLs (11 of 11 were TIA-1+, 4 of 4 were perforin+). In situ hybridization for Epstein-Barr virus-encoded RNA (EBER-1) was negative in all cases. Most patients responded to systemic chemotherapy or local radiation therapy. Seven patients are alive: four without disease (19-73 months) and three with disease (32-72 months); four died: three of disease (3-25 months) and one without disease (42 months). We conclude that SPTCLs are clonal, EBV-, cytotoxic T-cell lymphomas derived from alphabeta T-cells or gammadelta T-cells. The gammadelta SPTCLs appear to be preferentially derived from the Vdelta2+ subset. Subcutaneous panniculitis-like T-cell lymphoma may be rapidly fatal or indolent; local therapy may be appropriate for some patients.

Overexpression of p53 protein in cutaneous T cell lymphoma: relationship to large cell transformation and disease progression.

The molecular mechanisms by which advanced cases of cutaneous T cell lymphoma (CTCL) (mycosis fungoides/Sezary syndrome) undergo large cell transformation (LCT) and develop the morphologic appearance of a large cell lymphoma, are undefined. We used immunohistochemical analysis and polymerase chain reaction/single strand conformational polymorphism to examine whether p53 mutations are associated with disease progression and LCT in CTCL. p53 protein immunohistochemistry was performed on 37 paraffin embedded biopsies from 27 patients with CTCL; LCT was present in 15 biopsies. Overexpression of p53 protein was found in 11 of 37 CTCL biopsies including 10 of 15 biopsies (67%) with LCT in which p53 staining was predominantly seen in large transformed cells. In contrast, p53 immunostaining was found in only one of 22 CTCL biopsies without LCT (p < 0.0004). Serial biopsies revealed acquisition of p53 expression following LCT in two patients in whom initial diagnostic biopsies without LCT were p53 negative by immunostaining. All p53 protein positive biopsies were from advanced lesions (cutaneous tumors or extracutaneous sites); none of 12 patch/plaque stage CTCL biopsies demonstrated p53 staining. Polymerase chain reaction/single strand conformational polymorphism and sequencing analysis of p53 exons 4-8 was performed in 11 cases where frozen tissue was available. No mutations were detected in six cases positive for p53 protein expression. These results suggest overexpression of p53 protein in LCT and disease progression of CTCL by a mechanism other than p53 gene mutation, in most cases.

Use of serum soluble interleukin-2 receptor levels to monitor the progression of cutaneous T-cell lymphoma.

BACKGROUND: The serum concentration of soluble alpha chain of the interleukin-2 receptor (sIL-2R) correlates with tumor burden in cutaneous T-cell lymphoma (CTCL). Therefore the sIL-2R level may be useful to monitor the condition of patients treated with extracorporeal photopheresis or other treatments. OBJECTIVE: Our goal was to determine the utility of serum sIL-2R as a test in monitoring of patients with advanced CTCL. METHODS: Serum sIL-2R was measured serially in 36 patients with advanced CTCL treated with extracorporeal photopheresis and other modalities (interferon alfa, methotrexate, topical nitrogen mustard, electron beam). RESULTS: Serum concentrations of sIL-2R as well as lactate dehydrogenase (LDH) correlated strongly with lymph node size, but only sIL-2R correlated significantly with the severity of skin manifestations in erythrodermic patients. In addition, serum sIL-2R, but not LDH, was significantly higher in patients with nodal involvement. The level of sIL-2R also was significantly higher in patients with large-cell transformation in the skin or lymph nodes compared with patients without transformed disease. During treatment, serum concentrations of both serum sIL-2R and LDH correlated with changes in clinical status, but only sIL-2R showed statistically significant differences in mean levels for different relative global response scores. Pretreatment levels of both sIL-2R and LDH correlated significantly with survival, but only sIL-2R retained significance when both were entered into the Cox proportionate hazards model. CONCLUSION: The concentration of serum sIL-2R correlates well with disease status and is more useful than LDH or Sézary cell counts to monitor clinical change in patients with advanced CTCL. Moreover, our data suggest that sIL-2R is produced at a relatively low rate by tissue-based lymphoma cells, and that large-cell transformation in CTCL results in marked increase in sIL-2R production in some patients.

The pathogenesis of large cell transformation in cutaneous T-cell lymphoma is not associated with t(2;5)(p23;q35) chromosomal translocation.

In 20%-50% of the advanced cutaneous T-cell lymphomas (CTCL), malignant T cells undergo large cell transformation (LCT). The malignant T cells of LCT in CTCL can share morphologic and immunophenotypic similarities with CD30 (Ki-1)-positive anaplastic large cell lymphoma (ALCL), suggesting a common mechanism of pathogenesis. The t(2;5) (p23;q35) translocation, resulting in the fusion of the nucleophosmin (NPM) gene and the anaplastic lymphoma kinase (ALK) gene, is associated with primary CD30+ ALCL. To determine whether acquisition of this chromosomal translocation is involved in the pathogenesis of LCT in CTCL, we examined 12 tumor samples from 9 CTCL patients, including 8 with LCT-CTCL and one with concurrent CTCL and Hodgkin's disease, for the presence of the t(2;5) translocation. Numerous CD30+ large cells were present in 4 LCT-CTCL consistent with secondary CD30+ ALCL; CD30 was expressed by <10% of the large cells in another case and was negative in the other 3 lymphomas. Using primers spanning the NPM/ALK fusion junction, PCR amplification following reverse transcription (RT) of mRNA failed to show the products of NPM/ALK fusion in all samples tested. Thus, the t(2;5) (p23;q35) translocation does not appear to be involved in the molecular pathogenesis of LCT in CTCL, including CD30+ cases.

Folliculotropic mycosis fungoides with large-cell transformation presenting as dissecting cellulitis of the scalp.

Follicular mycosis fungoides (MF) is a rare variant of cutaneous T-cell lymphoma (CTCL) in which malignant lymphocytes preferentially infiltrate hair follicles. This report describes a patient with follicular mycosis fungoides presenting in a manner similar to dissecting cellulitis of the scalp with nonhealing, draining nodular lesions. Follicular mucinosis associated with folliculotropic mycosis fungoides resulted in follicular disruption and deep dissecting cellulitis. Large-cell transformation of CTCL was present in the initial diagnostic scalp and axillary lymph node specimens. The patient died from progressive CTCL 9 months following initial diagnosis despite electron beam radiation, topical mechlorethamine, interferon-alpha, and systemic chemotherapy. This case indicates that large-cell transformation of folliculotropic mycosis fungoides is an aggressive form of CTCL, and that folliculotropic mycosis fungoides can give rise to lesions which resemble dissecting cellulitis of the scalp. Upregulation of intercellular adhesion molecule-1 (ICAM-1) on follicular epithelium adjacent to lymphocyte function-associated antigen-1 (LFA-1)-positive folliculotropic lymphoma cells in this report provides insight into lymphocyte homing mechanisms in folliculotropic MF.