%0 Journal Article %T One Patient, Two Uncommon B-Cell Neoplasms: Solitary Plasmacytoma following Complete Remission from Intravascular Large B-Cell Lymphoma Involving Central Nervous System %A Joycelyn Lee %A Soo Yong Tan %A Leonard H. C. Tan %A Hwei Yee Lee %A Khoon Leong Chuah %A Tiffany Tang %A Richard Quek %A Kevin Tay %A Miriam Tao %A Soon Thye Lim %A Mohamad Farid %J Case Reports in Medicine %D 2014 %I Hindawi Publishing Corporation %R 10.1155/2014/620423 %X Second lymphoid neoplasms are an uncommon but recognized feature of non-Hodgkin¡¯s lymphomas, putatively arising secondary to common genetic or environmental risk factors. Previous limited evaluations of clonal relatedness between successive mature B-cell malignancies have yielded mixed results. We describe the case of a man with intravascular large B-cell lymphoma involving the central nervous system who went into clinical remission following immunochemotherapy and brain radiation, only to relapse 2 years later with a plasmacytoma of bone causing cauda equina syndrome. The plasmacytoma stained strongly for the cell cycle regulator cyclin D1 on immunohistochemistry, while the original intravascular large cell lymphoma was negative, a disparity providing no support for clonal identity between the 2 neoplasms. Continued efforts atcataloging and evaluating unique associations of B-cell malignancies are critical to improving understanding of overarching disease biology in B-cell malignancies. 1. Manuscript Second lymphoid neoplasm following the diagnosis and treatment of non-Hodgkin¡¯s lymphoma (NHL) is a recognized phenomenon. A systematic analysis of national cancer registries involving more than 100000 patients with NHL revealed a 2-3-fold increase in incidence of a second lymphoid neoplasm [1]. The causes for this tendency are diverse, complex, and incompletely understood. While myeloid malignancies, also slightly more common in patients with prior NHL, are known to be induced by cytotoxics like alkylators and anthracyclines used in NHL treatment, second lymphoid cancers are less plausibly attributable to the mutagenic effects of antecedent therapy. The presence of exposures common to the pathogenesis of successive malignancies is one likely underlying factor; for instance, coexistence of immunosuppression and oncogenic viruses like Epstein-Barr virus (EBV) is implicated in cases of EBV-related diffuse large B-cell lymphoma (DLBCL) developing following angioimmunoblastic T-cell lymphoma (AITL) [2]. Similarly, multiple myeloma and chronic lymphocytic leukemia (CLL), which have several analogous biological features (e.g., precursor monoclonal proliferations), have been infrequently associated in individuals [3], again suggesting shared underlying genetic and/or environmental triggers [4]. We describe here a unique case of a plasma cell neoplasm arising following successful treatment of an aggressive B-cell lymphoma. 2. Case Presentation A 59-year-old man of Portuguese descent presented with headaches, confusion, and seizures one week after being started on %U http://www.hindawi.com/journals/crim/2014/620423/