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Key players on the immunosurveillance program, T cells are regulated by their surface receptors such as T-cell receptor (TCR), and costimulatory molecules, optimizing T-cell activation. Some of these costimulatory molecules, such as the cytotoxic T-lymphocyte antigen 4 (CTLA-4), induce inhibitory effects on T cells. By "inhibiting the inhibitor" CTLA-4-blocking monoclonal antibodies represent a novel class of weapons against cancers. To better understand the promising future and the limits of this immunotherapy, this review dissects the molecular inhibitory mechanisms induced by CTLA-4 in T cells., (© 2011 médecine/sciences – Inserm / SRMS.)

The goal of this presentation is to describe current and future aspects of the operations within the consortium of Biological Resource Centres (BRC) and Tumour cell and tissue banks of the Marseilles metropolitan area. The consortium was created in year 2001, through the association of several tissue and cell banks that were operating for many years in Marseilles. Existing collections are not exclusively collections of tumour cells or tissues; however, the two tumour cell and tissue banks located at the Regional Cancer Research Centre and at the University Hospital account for a very significant proportion of the collections. Our collective work leads to the recognition and funding of the consortium by Inserm, through the "Collections 2003" grant. The consortium objectives are to define a common scientific strategy, to share professional practices in the logistics and database management of the banks, to establish a quality management program, and to build a common catalogue that describes existing biological resources. Through these efforts, the ultimate goal is to adopt rules that define BRC, as defined by the Organization for Economic Co-operation and Development (OECD).

A 44-year-old woman presenting with an inflammatory and palpable firm breast lump underwent surgical excision. Intraoperative frozen section analysis showed an extensive lesion consisting of ducts with intraluminal "necrosis". In addition, a very dense stromal inflammation was observed around these ducts, suggesting an invasive ductal carcinoma with predominant intraductal proliferation. However, on paraffin sections, epithelial cells close to the lymphocytic infiltrate were rare, subatrophic, without any neoplastic feature. The density and architecture of the lymphocytic infiltrate mimicked a breast lymphoma. However, immunochemistry and molecular biology investigation favored the diagnosis of a tumor-like lymphocytic mastitis. Although extremely rare, this particular form of lymphocytic mastitis, a diagnostic pitfall particularly during peroperative examination, should be recognized by pathologists.

We report the case of a plasmablastic lymphoma involving the skin in a 45 year-old HIV-positive patient. Plasmablastic lymphoma was first described in 1997 and is considered to be a diffuse large B-cell lymphoma with a unique immunophenotype and a predilection for the oral cavity. In this case, the tumor was revealed by multiple purple cutaneous nodules predominantly localized on the trunk and proximal parts of the limbs. A skin biopsy led to the diagnosis of plasmablastic lymphoma in view of the presence of a dense nodular infiltrate invading the dermis and subcutaneous fat composed of large cells that expressed neither the leucocyte common antigen nor the B- and T-cell antigens CD20 and CD3, but which showed a strong immunostaining with plasma cell marker VS38c. Most of the cells expressed Kappa light chain of immunoglobulins, they did not express Lambda light chain. In situ hybridization with EBER probe revealed detection of Epstein Barr virus in about 15 % of tumor cells. The clinical course was aggressive and rapidly fatal. Despite one cycle chemotherapy the patient died four months after presentation. HIV-associated plasmablastic lymphoma is a poor prognosis malignancy that may resist typing due to the lack of expression of commonly used lymphoid markers.

Inflammatory Breast Carcinoma (IBC) is a rare but aggressive form of breast carcinoma. Characteristic clinical and pathological features are well documented. Pathological response to chemotherapy is currently the only identified prognostic factor. This high-grade tumor exhibits phenotypical features of an aggressive tumor: absence of hormonal receptors in 56 to 83% of cases, high proliferating index, p53 expressed in 30 to 69%, Immunohistochemistry (IHC) detection of HER2 over expression in 38 to 60%. Current work on IBC points out specific molecular mechanisms: adhesion molecules such as E-Cadherin, apomucin MUC1 and angiogenesis processes contribute to the IBC phenotype. So does a gene named WISP3. This gene has been recently cloned and sequenced. It has been shown to be lost in IBC and could control tumor growth, invasion, and angiogenesis. This paper summarizes current knowledge on IBC and describes a new basis for a molecular definition of IBC.

Lymphomas are the most frequent haematological malignancies in France. Their histoclinical heterogeneity reflects their complex and combinatorial nature which remains poorly elucidated at the molecular level. Today, DNA arrays allow to tackle this diversity by measuring the mRNA expression level of thousands of genes simultaneously in one sample. Recent publications show the potential of DNA arrays to improve the prognostic classification of diffuse large B cell lymphomas and of Hodgkin's lymphoma, by identifying new tumour classes unrecognised by classical factors.