Intravascular CNS lymphoma: Successful therapy using high-dose methotrexate-based polychemotherapy

Rare central nervous system lymphomas

Central nervous system (CNS) lymphomas are rare malignancies characterised by lymphoid infiltration into the brain, spinal cord, cranial nerves, meninges and/or eyes in the presence or absence of previous or concurrent systemic disease. Most CNS lymphomas are of the diffuse large B-cell lymphoma (DLBCL) subtype for which treatment strategies, particularly the use of high-dose methotrexate-based protocols and consolidation with autologous stem cell transplantation, are well established. Other histopathological subtypes of CNS lymphoma are comparatively less common with published data on these rare lymphomas dominated by smaller case series and retrospective reports. Consequently, there exists little clinical consensus on the optimal methods to diagnose and manage these clinically and biologically heterogeneous CNS lymphomas. In this review article, we focus on rarer CNS lymphomas, summarising the available clinical data on incidence, context, diagnostic features, reported management strategies, and clinical outcomes.

Intravascular Lymphoma in the CNS: Options for Treatment

Purpose of review The purpose of this review was to discuss therapeutic manipulations and effective current interventions available to treat intravascular lymphoma in the central nervous system.

Recent findings Patients experienced resolution and remission of disease for 14 months and up to 2 years after eight cycles of R-CHOP and four courses of intrathecal therapy with MTX, cytarabine, and prednisolone. Intravascular use of unfractionated heparin during therapy may contribute to better outcome.

Summary Series of therapeutic avenues were analyzed and compared. The effective current treatment of intravascular lymphoma in the CNS is considered to be a combinational intrathecal methotrexate-based chemotherapy with rituximab. Since intrathecal administration bypasses the blood–brain barrier, lower doses can be given, which thereby minimizes systemic toxicity. Practical use of intrathecal chemotherapy is also justified for prophylaxis in intravascular lymphoma-diagnosed patients without CNS involvement.

Brain biopsy in neurologic decline of unknown etiology

Brain biopsies have an uncertain role in the diagnosis of patients with dementia or neurologic decline of unknown etiology. They are often performed only after an exhaustive panel of less invasive tests and procedures have failed to provide a definitive diagnosis. The objective of this study was to evaluate the sensitivity of brain biopsies in this patient group through the retrospective analysis of 53 brain biopsies performed for neurologic disease of unknown etiology at a single tertiary care institution between December 2001 and December 2011. Patients with known nonlymphomatous neoplasms thought to be associated with the neurologic symptoms or with immunodeficiency were excluded from the study. Furthermore, the clinical presentation, imaging and laboratory tests were compared between diagnostic groups to identify factors more likely to yield a diagnosis. Sixty percent of the biopsies were diagnostic (32 of 53), with the most common histologic diagnosis of central nervous system lymphoma in 14 of 53 patients (26% of total) followed by infarct in four subjects (7.5%). A few patients were found to have rare and unsuspected diseases such as lymphomatosis cerebri, neurosarcoidosis and neuroaxonal leukodystrophy. Complications from biopsy were uncommon and included hemorrhage and infection with abscess formation at the biopsy site. These results suggest that brain biopsies may be useful in difficult cases in which less invasive measures have been unable to yield a definitive diagnosis.

CNS lymphoma: a practical diagnostic approach

The concept and understanding of central nervous system (CNS) lymphoma have greatly evolved in the past few years. Better characterization of a number of lymphoproliferative neoplasms through clinical, immunophenotyping, and molecular studies is reflected in a much more complex WHO Classification of Tumours of Hematopoietic and Lymphoid Tissue. The term "primary CNS lymphoma" is now restricted to primary diffuse large B-cell lymphoma confined to the CNS (and/or to the eye) that occurs in immunocompetent patients. Many other lymphoma subtypes, some of which are primary or exclusive to the CNS, such as lymphomas of the dura and immunodeficiency-associated lymphomas, are excluded from this definition. We describe the clinical and morphologic features of a diverse group of lymphomas occurring in the CNS, including primary CNS lymphoma, primary vitreoretinal lymphoma, lymphomatosis cerebri, Epstein-Barr virus-associated lymphoproliferative disorders, low-grade B-cell lymphoma, T-cell lymphoma, anaplastic large cell lymphoma, intravascular large B-cell lymphoma, and Hodgkin lymphoma. The purpose of this review is to provide a practical approach to the diagnosis of an often-challenging entity, focusing on how to maximize the use of small tissue biopsies and prevent diagnostic traps, which we have encountered with similar cases. Clinical, radiologic, and histologic examples are presented.

One Patient, Two Uncommon B-Cell Neoplasms: Solitary Plasmacytoma following Complete Remission from Intravascular Large B-Cell Lymphoma Involving Central Nervous System

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.