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Tuesday, October 20, 2009

Primary cutaneous marginal zone lymphoma

Primary cutaneous marginal zone lymphoma

Service de dermatologie, Université Claude Bernard Lyon I, Hospices Civils de Lyon, Lyon, France.

Primary cutaneous marginal zone B-cell lymphoma (PCMZL) is included in the group of extranodal marginal zone B-cell lymphoma involving mucosal sites. Many evidences suggest that chronic antigen stimulation is a key-player in its pathogenesis. While Helicobacter pylori seems not to be implicated in PCMZL, Borrelia Burgdorferi's role is still matter of debate since the results are discordant between European and North American/Asian countries. However Borrelia subspecies are different between the studied areas and this difference could be a confounding factor. Then ubiquitous candidate antigen is still missing. Beyond these discrepancies the treatment of diffuse PCMZL has been recently improved. If local therapies (surgery, radiation) are the gold standard for localized disease, rituximab can also be considered as an alternative for disseminated or plurifocal PCMZL.


Primary cutaneous marginal zone B-cell lymphoma: clinical and histological aspects

Pathologica. 2009 Feb

Department of Dermatology, Charles Nicolle Hospital, Tunis, Tunisia.

According to the WHO-EORTC classification of cutaneous lymphomas, primary cutaneous marginal zone B-cell lymphoma are now well characterized. We report here a case of primary cutaneous marginal zone B-cell lymphoma in a 51 year-old man in which the diagnosis was made using both histology and immunopathology. The patient had no remarkable medical history, no history of either acute inflammation or insect bite, and presented with a 5 cm solitary asymptomatic erythematous firm, multinodular and infiltrated plaque on the back for 12 months. Histological examination and immunohistochemical study of a cutaneous biopsy provided a differential diagnosis between B cell lymphoma and lymphocytoma cutis. Full body work up revealed no signs of extracutaneous dissemination. The patient underwent surgical excision of the nodule. Histological examination showed a histological and immunophenotyping profile typical of primary cutaneous marginal zone B-cell lymphoma. The lesion was completely excised with clear margins and no recurrence occurred after a 12 month-follow-up period. Primary cutaneous marginal zone B-cell lymphoma are low-grade lymphomas that have an indolent course and a high tendency to recur. They should be differentiated from lymphocytoma cutis and from the other types of cutaneous B cell lymphomas that have a different course and prognosis.

PMID: 19771768 [PubMed - in process]

Vitreous metastases of primary cutaneous B-cell lymphoma.

Vitreous metastases of primary cutaneous B-cell lymphoma.

Texas Retina Associates, Arlington, TX, USA.

Purpose: To describe two cases of vitreous metastases of primary cutaneous B-cell lymphoma (PCBCL). Methods: Observational case series. Results: A 73-year-old man and an 81-year-old woman, both with a history of PCBCL, diffuse large cell type, presented with decreased visual acuity due to vitritis. Both patients underwent vitreous biopsy that demonstrated B-cell lymphoma, large cell type, and confirmed metastases of cutaneous B-cell lymphoma to the vitreous. Conclusion: PCBCL, diffuse large cell type, is a rare form of non-Hodgkin lymphoma that can metastasize to the vitreous without visible chorioretinal involvement.

PMID: 19831568 [PubMed - in process]

Monday, October 12, 2009

IRF4 Gene Rearrangements Define a Subgroup of CD30-Positive Cutaneous T-Cell Lymphoma

IRF4 Gene Rearrangements Define a Subgroup of CD30-Positive Cutaneous T-Cell Lymphoma:
A Study of 54 Cases

Department of Histology and Molecular Pathology of Tumors, University Bordeaux 2, Bordeaux, France.

Correspondence: Professor Jean-Philippe Merlio, Department of Histology and Molecular Pathology, University Bordeaux 2, 146 rue Leo Saignat, Bordeaux 33076, France.

The identification of IFN regulatory factor 4 gene (IRF4) translocation in 8 out of 14 cases of cutaneous anaplastic large cell lymphomas (C-ALCLs) (Leukemia, 2009; 23(3):574-80) prompted us to study IRF4 locus status in different cutaneous T-cell lymphoma (CTCL) subtypes. Fluorescence in situ hybridization (FISH) was used with break-apart dual-color probes. Sixty samples from 54 patients were analyzed with 23 C-ALCL, 11 transformed mycosis fungoides (T-MF), 7 lymphomatoid papulosis (LyP), and 13 Sézary syndrome (SS) cases. IRF4 immunostaining was performed in 32 cases. We observed a split FISH signal pattern indicating a translocation at the IRF4 locus in 6 out of 23 C-ALCL (26%) and 2 out of 11 T-MF (18.2%) cases. Extra copies of the IRF4 locus were found in 4 out of 13 SS, 1 out of 11 T-MF, and 1 out of 23 C-ALCL cases, corresponding to either aneuploidy, chromosome 6 trisomy, or 6p partial gain. The IRF4 expression was not correlated with the presence of IRF4 alteration in C-ALCL or T-MF. Interestingly, IRF4 rearrangements define a subgroup of CD30-positive C-ALCL and T-MF cases. Conversely, T-MF cases with IRF4 rearrangements may correspond to the development of C-ALCL in MF patients and not to large cell transformation. Investigation of the biological pathways triggered by IRF4 rearrangements and/or expression in CTCL will provide a biological basis for IRF4-directed therapy.Journal of Investigative Dermatology advance online publication, 8 October 2009; doi:10.1038/jid.2009.314.



ALCL, anaplastic large cell lymphoma; ALK, anaplastic lymphoma kinase; C-ALCL, cutaneous anaplastic large cell lymphoma; CTCL, cutaneous T-cell lymphoma; FISH, fluorescencein situ hybridization; IRF4, IFN regulatory factor 4; LyP, lymphomatoid papulosis; MF, mycosis fungoides; MM, multiple myeloma; MUM1, multiple myeloma antigen 1; PTCL, peripheral T-cell lymphoma; T-MF, transformed mycosis fungoides