AbstractAbstract 5103An increased risk of alk-negative T-cell derived anaplastic large-cell lymphoma (T-ALCL) in patients with breast prostheses has been suggested, although unequivocal evidence of an association has not yet been provided. Several reports have also suggested that silicone, one of the major components of breast prostheses, activates the immune system, and induction of myeloma has been shown in a murine model. While association to breast prostheses has been described in as many as 48 patients with T-cell derived ALCL1, only one case of breast implant-associated B-cell derived lymphoma, displaying a follicular histology2, has been reported so far. We here present a case of DLBCL diagnosed in 2006 in a 66 year-old woman, who had undergone cosmetic implantation of bilateral breast prostheses 20 years previously. The disease initially involved right cervical and mediastinal nodes. She was treated with chemo-immunotherapy (rituximab + CHOP q 3 weeks for a total of 8 series) achieving a complete remission (CR) by summer 2006. Almost 1 year later, a nodal DLBCL relapse occurred at cervical level. The patient was again treated with chemoimmunotherapy (rituximab+ dexamethasone, high-dose cytosine arabinoside and cis-platin q 3 weeks for a total of 3 series). A new CR was obtained and consolidated with an autologous transplant with BEAM conditioning in March 2008. More than a year later, a new cervical node relapse occurred along with a small focus in the lung (not bioptically verified). From then on, the patient received multiple therapies, every time with initial chemosensitivity, but quickly followed by new progression as soon as therapy was discontinued. According to PET assessment, there has never been any tumour manifestation below the diaphragm, and no lymphoma infiltration was detected at any time in the bone marrow. As of June 2010, the patient developed multiple cutaneous and subcutaneous tumours corresponding to the anterior thoracic wall in close proximity to the upper quadrants of both breasts. These tumors were preceeded by an erythematous lesion clearly demarcating the cutaneous area of the anterior thoracic wall and breasts corresponding to the underlying implants. Cutaneous biopsies taken at this erythematous stage already revealed diffuse DLBCL infiltration of the skin and subcutis. Cutaneous and subcutaneous biopsies showed alk-negative, CD30-negative CD20-positive DLBCL. All previous lymph node biopsies are CD20 positive, bcl-2 and bcl-6 positive and negative for CD10. A fraction of tumour cells expressed MUM-1. By and large, no major changes in the immunohistochemical profile of the tumor have been observed since the original diagnosis in 2006. The striking anatomical localization of the latest relapse, but also the fact that the patient's disease over the years persistently manifested itself in lymph node drainage regions adjacent to or in the near proximity of the patient's breast implants, may be suggestive of a chronic antigenic stimulation eventually resulting in a malignant B-cell lymphoproliferation of DLBCL type. DLBCL histology has not previously been reported in possible association with breast implants. Disclosures:No relevant conflicts of interest to declare.