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3.
Histopathology ; 67(4): 425-41, 2015 Oct.
Article in English | MEDLINE | ID: mdl-24438036

ABSTRACT

AIMS: Aggressive epidermotropic cutaneous CD8(+) lymphoma is currently afforded provisional status in the WHO classification of lymphomas. An EORTC Workshop was convened to describe in detail the features of this putative neoplasm and evaluate its nosological status with respect to other cutaneous CD8(+) lymphomas. METHODS AND RESULTS: Sixty-one CD8(+) cases were analysed at the workshop; clinical details, often with photographs, histological sections, immunohistochemical results, treatment and patient outcome were discussed and recorded. Eighteen cases had distinct features and conformed to the diagnosis of aggressive epidermotropic cutaneous CD8(+) lymphoma. The patients typically present with widespread plaques and tumours, often ulcerated and haemorrhagic, and histologically have striking pagetoid epidermotrophism. A CD8(+) /CD45RA(+) /CD45RO(-) /CD2(-) /CD5(-) /CD56(-) phenotype, with one or more cytotoxic markers, was found in seven of 18 patients, with a very similar phenotype in the remainder. The tumours seldom involve lymph nodes, but mucosal and central nervous system involvement are not uncommon. The prognosis is poor, with a median survival of 12 months. Examples of CD8(+) mycosis fungoides, lymphomatoid papulosis and Woringer-Kolopp disease presented the typical features well documented in the CD4(+) forms of those diseases. CONCLUSIONS: Aggressive epidermotropic cutaneous CD8(+) lymphoma is a distinct lymphoma that warrants inclusion as a distinct entity in future revisions of lymphoma classifications.


Subject(s)
CD8-Positive T-Lymphocytes/immunology , Lymphoma, T-Cell, Cutaneous/classification , Lymphoma, T-Cell, Cutaneous/diagnosis , Lymphoma, T-Cell, Cutaneous/immunology , Adult , Aged , Aged, 80 and over , Female , Humans , Immunophenotyping , Male , Middle Aged
5.
J Cutan Pathol ; 35(10): 899-910, 2008 Oct.
Article in English | MEDLINE | ID: mdl-18494816

ABSTRACT

Activator protein 1 (AP-1) consists of a group of transcription factors including the JUN and FOS family proteins with diverse biological functions. This study assessed the genomic and expression status of the AP-1 transcription factors in primary cutaneous T-cell lymphoma (CTCL) by using immunohistochemistry (IHC), Affymetrix expression microarray, real-time reverse transcriptase-polymerase chain reaction (RT-PCR) and fluorescent in situ hybridization (FISH). IHC showed JUNB protein expression in tumor cells from 17 of 33 cases of Sezary syndrome (SS) and JUND protein expression in 16 of 23 mycosis fungoides cases. There was no correlation between JUNB and CD30 expression. However, 7 of 12 JUNB-positive SS cases expressed both phosphorylated and total extracellular signal-regulated kinase (ERK) 1/2 mitogen-activated protein kinase (MAPK) proteins. Expression microarray showed over threefold increased expression of JUNB in three of six SS patients and similar findings were also noted after re-analysis of previously published data. Real-time RT-PCR confirmed the overexpression of JUNB in four SS cases and of JUND in three of four cases. FISH showed increased JUNB copy number in four of seven SS cases. These findings suggest that deregulation of AP-1 expression in CTCL is the result of aberrant expression of JUNB and possible JUND resulting from genomic amplification and constitutive activation of ERK1/2 MAPK in this type of lymphoma.


Subject(s)
Mycosis Fungoides/metabolism , Proto-Oncogene Proteins c-jun/biosynthesis , Sezary Syndrome/metabolism , Skin Neoplasms/metabolism , Transcription Factor AP-1/biosynthesis , Gene Expression , Gene Expression Profiling , Humans , Immunohistochemistry , In Situ Hybridization, Fluorescence , Mitogen-Activated Protein Kinases/metabolism , Mycosis Fungoides/genetics , Oligonucleotide Array Sequence Analysis , Proto-Oncogene Proteins c-jun/genetics , Reverse Transcriptase Polymerase Chain Reaction , Sezary Syndrome/genetics , Skin Neoplasms/genetics , Transcription Factor AP-1/genetics
6.
Blood ; 109(1): 61-4, 2007 Jan 01.
Article in English | MEDLINE | ID: mdl-16960151

ABSTRACT

Fusion genes derived from the platelet-derived growth factor receptor beta (PDGFRB) or alpha (PDGFRA) play an important role in the pathogenesis of BCR-ABL-negative chronic myeloproliferative disorders (CMPDs). These fusion genes encode constitutively activated receptor tyrosine kinases that can be inhibited by imatinib. Twelve patients with BCR-ABL-negative CMPDs and reciprocal translocations involving PDGFRB received imatinib for a median of 47 months (range, 0.1-60 months). Eleven had prompt responses with normalization of peripheral-blood cell counts and disappearance of eosinophilia; 10 had complete resolution of cytogenetic abnormalities and decrease or disappearance of fusion transcripts as measured by reverse transcriptase-polymerase chain reaction (RT-PCR). Updates were sought from 8 further patients previously described in the literature; prompt responses were described in 7 and persist in 6. Our data show that durable hematologic and cytogenetic responses are achieved with imatinib in patients with PDGFRB fusion-positive, BCR-ABL-negative CMPDs.


Subject(s)
Antineoplastic Agents/therapeutic use , Fusion Proteins, bcr-abl/blood , Myeloproliferative Disorders/drug therapy , Oncogene Proteins, Fusion/blood , Piperazines/therapeutic use , Protein Kinase Inhibitors/therapeutic use , Pyrimidines/therapeutic use , Receptor, Platelet-Derived Growth Factor beta/blood , Adult , Aged , Aged, 80 and over , Benzamides , Biomarkers, Tumor/blood , Child , Child, Preschool , Drug Evaluation , Eosinophilia/etiology , Female , Follow-Up Studies , Humans , Imatinib Mesylate , Infant , Leukemia, Myeloid, Chronic, Atypical, BCR-ABL Negative/blood , Leukemia, Myeloid, Chronic, Atypical, BCR-ABL Negative/drug therapy , Leukemia, Myeloid, Chronic, Atypical, BCR-ABL Negative/genetics , Male , Middle Aged , Myeloproliferative Disorders/blood , Myeloproliferative Disorders/genetics , Oncogene Proteins, Fusion/genetics , RNA, Messenger/blood , RNA, Neoplasm/blood , Receptor, Platelet-Derived Growth Factor beta/genetics , Retrospective Studies , Reverse Transcriptase Polymerase Chain Reaction , Translocation, Genetic , Treatment Outcome
7.
J Am Acad Dermatol ; 55(5): 903-6, 2006 Nov.
Article in English | MEDLINE | ID: mdl-17052504

ABSTRACT

We report 3 cases of lymphomatoid papulosis (LyP) with a CD56+, cytotoxic immunophenotype. All 3 patients presented with clinical histories typical of LyP, with one patient having associated mycosis fungoides. Histologically, two cases were type A LyP and one was type B. All 3 cases demonstrated a T-cell receptor clone in lesional skin without evidence of blood involvement. The atypical lymphocytes in each of the 3 cases expressed cytotoxic granules (T-cell intracellular antigen-1+ and granzyme B+) and were CD8+ and CD56+. Expression of CD56 is associated with a poor prognosis in subcutaneous panniculitis-like T-cell lymphoma and blastic natural killer cell lymphoma. However, the two cases of CD56+ LyP previously reported and the 3 cases in this series all appear to be pursuing an indolent course with no evidence of systemic disease.


Subject(s)
CD56 Antigen/analysis , Immunophenotyping , Lymphomatoid Papulosis/immunology , Adult , Biopsy , Cytotoxicity, Immunologic , Female , Gene Rearrangement, T-Lymphocyte , Humans , Immunohistochemistry , Immunophenotyping/methods , Lymphomatoid Papulosis/complications , Lymphomatoid Papulosis/genetics , Lymphomatoid Papulosis/pathology , Male , Middle Aged , Mycosis Fungoides/complications , Skin/pathology , Skin Neoplasms/complications
8.
J Invest Dermatol ; 126(6): 1388-95, 2006 Jun.
Article in English | MEDLINE | ID: mdl-16614728

ABSTRACT

Upregulation of cyclin D1/B-cell leukemia/lymphoma 1 (CCND1/BCL1) is present in most mantle cell lymphomas with the t(11;14)(q13;q32) translocation. However, little is known about the abnormalities of CCND1 and its regulator RB1 in primary cutaneous T-cell lymphomas (CTCL). We analyzed CCND and RB status in CTCL using fluorescent in situ hybridization (FISH), immunohistochemistry (IHC), and Affymetrix expression microarray. FISH revealed loss of CCND1/BCL1 in five of nine Sézary syndrome (SS) cases but gain in two cases, and RB1 loss in four of seven SS cases. IHC showed absent CCND1/BCL1 expression in 18 of 30 SS, 10 of 23 mycosis fungoides (MF), and three of 10 primary cutaneous CD30+ anaplastic large-cell lymphoma (C-ALCL). Increased CCND1/BCL1 expression was seen in nine MF, seven C-ALCL, and six SS cases. Absent RB1 expression was detected in 8 of 12 MF and 7 of 9 SS cases, and raised RB1 expression in 7 of 8 C-ALCL. Affymetrix revealed increased gene expression of CCND2 in four of eight CTCL cases, CCND3 in three cases, and CDKN2C in two cases with a normal expression of CCND1 and RB1. These findings suggest heterogeneous abnormalities of CCND and RB in CTCL, in which dysregulated CCND and RB1 may lead to impaired cell cycle control.


Subject(s)
Chromosome Deletion , Cyclin D1/genetics , Gene Expression Regulation, Neoplastic , Lymphoma, T-Cell, Cutaneous/genetics , Retinoblastoma Protein/genetics , Skin Neoplasms/genetics , Cell Nucleus/chemistry , Cell Nucleus/genetics , Chromosome Aberrations , Chromosomes, Human, Pair 11/genetics , Chromosomes, Human, Pair 14/genetics , Cyclin D1/analysis , Female , Humans , In Situ Hybridization, Fluorescence , Lymphoma, Large-Cell, Anaplastic/chemistry , Lymphoma, Large-Cell, Anaplastic/genetics , Lymphoma, T-Cell, Cutaneous/chemistry , Male , Mycosis Fungoides/chemistry , Mycosis Fungoides/genetics , Oligonucleotide Array Sequence Analysis , Retinoblastoma Protein/analysis , Sezary Syndrome/chemistry , Sezary Syndrome/genetics , Skin Neoplasms/chemistry , Up-Regulation
9.
J Am Acad Dermatol ; 54(4): 668-75, 2006 Apr.
Article in English | MEDLINE | ID: mdl-16546591

ABSTRACT

Lymphoma occurring after organ transplantation has been well described. The majority of cases are B-cell lymphomas and are usually associated with Epstein-Barr virus. Only a minority of posttransplant lymphomas are of T-cell origin, and primary cutaneous T-cell lymphoma (CTCL) is extremely rare. In this article, we report a case of cutaneous peripheral T-cell lymphoma, pleomorphic CD30+ large-cell type, and review the literature relating to posttransplant primary CTCL. Of the 23 cases of posttransplant primary CTCL, 5 patients had erythrodermic disease, and 8 had primary cutaneous anaplastic large cell lymphoma. In addition, there are two cases of mycosis fungoides, one case of subcutaneous panniculitis-like T-cell lymphoma, one case of CD30+ lymphomatoid papulosis, and 6 cases of peripheral T-cell lymphoma, of which 3 were CD30+ large cell lymphomas. Seventeen cases had renal transplants and the majority received both cyclosporine and azathioprine. No consistent viral association was noted among these cases. The sex ratio was 18:5 (male/female), and the mean age at diagnosis was 53 years. Mean time from transplantation to diagnosis is 6.4 years and mean survival time from diagnosis is 14.5 months. The prognoses normally associated with particular subsets of CTCL do not apply in the posttransplant setting.


Subject(s)
Kidney Transplantation/adverse effects , Lymphoma, T-Cell, Cutaneous/diagnosis , Skin Neoplasms/diagnosis , Humans , Immunosuppression Therapy/adverse effects , Lymphoma, T-Cell, Cutaneous/etiology , Lymphoma, T-Cell, Cutaneous/pathology , Lymphoma, T-Cell, Peripheral/diagnosis , Male , Middle Aged , Skin Neoplasms/etiology , Skin Neoplasms/pathology
10.
J Cutan Pathol ; 32(10): 647-74, 2005 Nov.
Article in English | MEDLINE | ID: mdl-16293178

ABSTRACT

UNLABELLED: The new WHO/EORTC classification for cutaneous lymphomas comprises mature T-cell and natural killer (NK)-cell neoplasms, mature B-cell neoplasms, and immature hematopoietic malignancies. It reflects the unique features of lymphoproliferative diseases of the skin, and at the same time it is as compatible as possible with the concepts underlying the WHO classification for nodal lymphomas and the EORTC classification of cutaneous lymphomas. This article reviews the histological, phenotypical, and molecular genetic features of the various nosological entities included in this new classification. These findings always have to be interpreted in the context of the clinical features and biologic behavior. AIM: To review the histological, phenotypical and molecular genetic features of the various nosological entities of the new WHO/EORTC classification for cutaneous lymphomas. METHODS: Extensive review of the literature cited in Medline and own data of the authors. RESULTS: The WHO/EORTC classification of cutaneous lymphomas comprises mature T-cell and NK-cell neoplasms, mature B-cell neoplasms and immature hematopoietic malignancies. It reflects the unique features of primary cutaneous lymphoproliferative diseases. CONCLUSION: This classification is as much as possible compatible with the concept of the WHO classification for nodal lymphomas and the EORTC classification of cutaneous lymphomas. The histological, phenotypical and molecular genetic features always have to be interpreted in the context of the clinical features and biologic behavior.


Subject(s)
Lymphoma/classification , Skin Neoplasms/classification , Europe , Humans , Immunophenotyping , International Agencies , Killer Cells, Natural/immunology , Killer Cells, Natural/pathology , Lymphoma/genetics , Lymphoma/immunology , Lymphoma/pathology , Lymphoma, B-Cell/classification , Lymphoma, B-Cell/genetics , Lymphoma, B-Cell/immunology , Lymphoma, B-Cell/pathology , Lymphoma, T-Cell, Cutaneous/classification , Lymphoma, T-Cell, Cutaneous/genetics , Lymphoma, T-Cell, Cutaneous/immunology , Lymphoma, T-Cell, Cutaneous/pathology , Skin Neoplasms/genetics , Skin Neoplasms/immunology , Skin Neoplasms/pathology , World Health Organization
12.
J Am Acad Dermatol ; 53(1): 158-63, 2005 Jul.
Article in English | MEDLINE | ID: mdl-15965442

ABSTRACT

We report 3 cases of mycosis fungoides (MF) with a CD56+ cytotoxic immunophenotype. Each patient presented with a different clinical phenotype: one exhibited limited poikilodermatous patches (skin stage T1); one, widespread hypopigmented lesions (skin stage T2); and one, poikiloderma with a single cutaneous tumor (skin stage T3). MF was confirmed both histologically and by the presence of a T-cell receptor clone in lesional skin in all cases. CD56 and T-cell intracellular antigen-1 were expressed by the malignant lymphocytes in all patients and two expressed CD8. No sample demonstrated loss of the pan T-cell markers CD2 or CD3. None of the 3 developed systemic disease and T-cell receptor gene analysis of peripheral blood was polyclonal in all cases. Only 3 cases of CD56+ MF have been reported previously, none of which exhibited tumor-stage disease. Currently, the disease in our patients appears to be behaving in a manner similar to that predicted for MF with a normal immunophenotype but the prognosis has to be guarded in view of the rarity of this subtype.


Subject(s)
CD56 Antigen , Mycosis Fungoides/immunology , Skin Neoplasms/immunology , Adult , Child , Female , Humans , Immunophenotyping , Male , Middle Aged
13.
Genes Chromosomes Cancer ; 42(2): 184-92, 2005 Feb.
Article in English | MEDLINE | ID: mdl-15540164

ABSTRACT

Previous cytogenetic studies in mycosis fungoides (MF) and Sezary syndrome (SS) have identified a large and poorly defined area of chromosomal deletion on chromosome 10q. We report an extensive fine-mapping allelotyping study using 19 microsatellite markers in the region 10q22.3-10q26.13. Allelic loss was identified by loss of heterozygosity analysis in 26 of 60 (43%) cases: 15 of 45 (33%) with MF and 11 of 15 (73%) with SS. MF and SS samples showed similar patterns of allelic loss with the identification of two discrete regions of deletion which were mutually exclusive in all but two cases. Within the first region of deletion at 10q23.33-10q24.1, around microsatellite marker D10S185 (2.77 Mb), 23 genes were identified, including three (KIF11, HHEX, and HELLS) with functions that, if dysregulated, could be critical in MF and SS. The second region of deletion, 10q24.33-10q25.1, around microsatellite marker D10S530 (3.92 Mb), encodes 11 genes, the majority of which have poorly identified functions. This extensive allelotyping study provides the basis for future highly selective candidate gene analyses.


Subject(s)
Chromosome Deletion , Chromosome Mapping/methods , Chromosomes, Human, Pair 10/genetics , Mycosis Fungoides/genetics , Sezary Syndrome/genetics , Skin Neoplasms/genetics , Genes, Neoplasm/genetics , Humans , Loss of Heterozygosity/genetics
16.
Arch Dermatol ; 140(4): 449-54, 2004 Apr.
Article in English | MEDLINE | ID: mdl-15096373

ABSTRACT

BACKGROUND: Chronic atopic eczema is not regarded as a precursor of malignancy, and, to our knowledge, there has been only one previous case report of CD30(+) cutaneous lymphoma in association with atopic dermatitis. OBSERVATIONS: We report 4 cases of CD30(+) lymphoproliferative disease in young adult patients with active atopic eczema dating from early childhood. Three patients developed primary cutaneous anaplastic large cell lymphoma, of whom 2 developed systemic disease and 1 died. The other patient developed lymphomatoid papulosis type A, which resolved after withdrawal of cyclosporine therapy. No other patient had received immunosuppressive therapy. Three had been treated with phototherapy, and 2 of these patients exhibited positive immunostaining for p53 within a proportion of the tumor cell population. CONCLUSIONS: Although we have not been able to establish a causative link, we believe that the association of these 2 conditions has not occurred by chance. Biopsies of lesional skin from subjects with atopic eczema exhibit a proportion of CD30 cells, and clonal transformation of this subpopulation might account for the CD30(+) lymphomas in our patients.


Subject(s)
Dermatitis, Atopic/complications , Ki-1 Antigen/immunology , Lymphoma, T-Cell, Cutaneous/complications , Lymphoma, T-Cell, Cutaneous/pathology , Skin Neoplasms/complications , Skin Neoplasms/pathology , Adult , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Biomarkers/analysis , Biopsy, Needle , Dermatitis, Atopic/drug therapy , Dermatitis, Atopic/pathology , Dermatologic Agents/therapeutic use , Female , Follow-Up Studies , Humans , Immunohistochemistry , Immunosuppressive Agents/therapeutic use , Lymphoma, T-Cell, Cutaneous/drug therapy , Male , Risk Assessment , Sampling Studies , Severity of Illness Index , Skin Neoplasms/drug therapy , Treatment Outcome
17.
J Am Acad Dermatol ; 50(5): 701-5, 2004 May.
Article in English | MEDLINE | ID: mdl-15097953

ABSTRACT

We retrospectively analyzed the first 461 cases entered into our cutaneous lymphoma database and found 285 cases of mycosis fungoides. We also identified 6 cases of malignant melanoma, all of which were found in patients with mycosis fungoides. The crude rate of melanoma in the general population in England, United Kingdom, in 1998 was 8.8/100,000 in men and 11.4/100,000 in women. The incidence of melanoma found in our cohort of patients with mycosis fungoides was far higher, and in 4 of the 6 patients cannot be explained on the basis of prior therapy. The reason for this association is unclear, but this report emphasizes the risk of second malignancies for patients with cutaneous T-cell lymphoma and melanoma.


Subject(s)
Melanoma , Mycosis Fungoides , Neoplasms, Multiple Primary , Skin Neoplasms , Adult , Aged , Female , Humans , Male , Melanoma/diagnosis , Melanoma/pathology , Middle Aged , Mycosis Fungoides/diagnosis , Mycosis Fungoides/pathology , Neoplasms, Multiple Primary/diagnosis , Neoplasms, Multiple Primary/pathology , Skin Neoplasms/diagnosis , Skin Neoplasms/pathology
18.
J Am Acad Dermatol ; 50(5): 792-6, 2004 May.
Article in English | MEDLINE | ID: mdl-15097969

ABSTRACT

Clinically amelanotic lentigo maligna often resembles an inflammatory lesion rather than a melanoma in situ. We present two cases of extensive amelanotic lentigo maligna presenting as gradually enlarging erythematous patches on the faces of women following incomplete excisions of lentigo maligna. Because of their site and size, therapeutic options were limited; the lesions have, however, resolved (clinically and histologically) following the topical application of 5% imiquimod cream. We discuss the rationale for the use of imiquimod in the treatment of lentigo maligna.


Subject(s)
Adjuvants, Immunologic/administration & dosage , Aminoquinolines/administration & dosage , Hutchinson's Melanotic Freckle/drug therapy , Skin Neoplasms/drug therapy , Administration, Topical , Aged , Female , Humans , Hutchinson's Melanotic Freckle/pathology , Hutchinson's Melanotic Freckle/surgery , Imiquimod , Middle Aged , Ointments , Skin Neoplasms/pathology , Skin Neoplasms/surgery
19.
Cancer ; 98(10): 2282-90, 2003 Nov 15.
Article in English | MEDLINE | ID: mdl-14601100

ABSTRACT

BACKGROUND: Mycosis fungoides (MF) is predominantly a disease of older patients, but occasionally occurs in children. The aims of the current study were to describe the clinical presentation, pathologic features, and disease progression (DP) in patients who developed MF before age 16 years. METHODS: A retrospective study was performed. Patients with juvenile-onset MF were identified from our databases. Clinical features were determined from the medical records and patient interviews. Histologic, immunohistochemical, and T-cell receptor (TCR) gene analysis was performed. RESULTS: Thirty-four patients were identified: 50% had Stage IA disease, 47% had Stage IB disease, and 3% had Stage IIA disease. The male-to-female ratio was 2:1. Clinical features included hypopigmented lesions (24%), poikiloderma (26%), pilotropic disease (9%), and disease associated with lymphomatoid papulosis (18%). Twenty-eight patients had diagnostic histology, and six patients were included on the basis of compatible histology and a TCR clone in lesional skin. A cytotoxic immunophenotype was observed in 38%, including 71% of patients with hypopigmented lesions. Overall disease-specific survival (DSS) rates at 5 and 10 years were 95% and 93%, respectively. DP rates were 5% at 5 years and 29% at 10 years. Subgroup analysis demonstrated improved DSS and reduced DP in patients with Stage IA disease, those with hypopigmented or poikilodermatous lesions, and those with associated lymphomatoid papulosis. CONCLUSIONS: The prognosis for juvenile-onset MF is similar to that of adult-onset disease. There was an overrepresentation of a cytotoxic phenotype, which was most marked in hypopigmented variants. Widespread cutaneous disease (Stage IB) indicated a less favorable outcome.


Subject(s)
Immunophenotyping , Mycosis Fungoides/genetics , Mycosis Fungoides/pathology , Skin Neoplasms/genetics , Skin Neoplasms/pathology , Adolescent , Age of Onset , Child , Child, Preschool , Disease Progression , Disease-Free Survival , Female , Follow-Up Studies , Humans , Immunohistochemistry , Infant , Male , Mycosis Fungoides/immunology , Neoplasm Staging , Prognosis , Sex Factors , Skin Neoplasms/immunology , Skin Pigmentation , Treatment Outcome
20.
J Invest Dermatol ; 121(4): 894-901, 2003 Oct.
Article in English | MEDLINE | ID: mdl-14632210

ABSTRACT

Fifty-one mycosis fungoides samples were analyzed for microsatellite instability (MSI) using the panel of markers recommended for hereditary nonpolyposis colorectal cancer kindred and a panel we designed for cutaneous T cell lymphoma in order to compare detection rates and determine if MSI is a genome-wide phenomenon. Samples demonstrating MSI were analyzed for abnormalities of the hMLH1 gene including loss of heterozygosity, mutations, and promoter hypermethylation. MSI was detected in 16% using the hereditary nonpolyposis colorectal cancer panel and 22% with the cutaneous T cell lymphoma panel. Overall, 27% demonstrated MSI and 73% had a stable phenotype. hMLH1 gene studies did not detect loss of heterozygosity or reveal any mutations. Promoter hypermethylation was detected in nine of 14 patients with MSI, however (64%). In addition hMLH1 and hMSH2 protein expression was studied using immunohistochemical techniques. Five of nine patients with MSI and hMLH1 promoter methylation showed abnormal hMLH1 protein expression with normal hMSH2 gene expression. All other patients tested demonstrated normal hMLH1 and hMSH2 protein expression. MSI was found to be more prevalent in tumor stage mycosis fungoides (47%) than early stage disease (20%) and was associated with an older age of onset of mycosis fungoides. MSI may be a consequence of hMLH1 promoter hypermethylation in mycosis fungoides patients and may prevent transcription in a subset of patients. This suggests that the development of a mutator phenotype may contribute to disease progression in mycosis fungoides.


Subject(s)
DNA Methylation , DNA-Binding Proteins , Microsatellite Repeats/physiology , Mycosis Fungoides/physiopathology , Neoplasm Proteins/genetics , Skin Neoplasms/physiopathology , Adaptor Proteins, Signal Transducing , Carrier Proteins , Female , Gene Expression , Humans , Immunohistochemistry , Loss of Heterozygosity , Male , Middle Aged , MutL Protein Homolog 1 , MutS Homolog 2 Protein , Mycosis Fungoides/metabolism , Mycosis Fungoides/mortality , Neoplasm Proteins/metabolism , Nuclear Proteins , Phenotype , Promoter Regions, Genetic/physiology , Proto-Oncogene Proteins/genetics , Skin Neoplasms/metabolism , Skin Neoplasms/mortality , Survival Rate
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