Central nervous system involvement in mantle cell lymphoma.

BACKGROUND: Extranodal involvement, including central nervous system (CNS), is a frequent event in patients with mantle cell lymphoma (MCL). However, the incidence, risk factors, and impact on outcome remain controversial. PATIENTS AND METHODS: Main clinical, biological, and evolutive features of 82 patients (60 males/22 females; median age: 61 years) diagnosed with MCL (blastoid, 26%) in a single institution were analyzed for risk of CNS involvement and prognosis. RESULTS: Most patients had advanced stage and intermediate or high-risk International Prognostic Index (IPI). Eleven patients eventually developed CNS involvement with an actuarial 5-year risk of 26% (95% confidence interval 10% to 42%). In one asymptomatic patient, cerebrospinal fluid infiltration was detected at staging maneuvers (1/62; 1.6%). The remaining 10 patients developed neurological symptoms during the course of the disease (median time from diagnosis, 25 months). Initial variables predicting CNS involvement were blastoid histology, high proliferative index measured by Ki-67 staining, high lactate dehydrogenase (LDH) and intermediate- or high-risk IPI. Histological subtype and serum LDH maintained significance in multivariate analysis. Treatment of CNS infiltration consisted of intrathecal chemotherapy (two cases), and intrathecal chemotherapy plus systemic treatment (seven cases). Median survival after CNS involvement was 4.8 months, patients with this complication having shorter survival than those with no CNS disease. CONCLUSION: This study confirms the high incidence of CNS involvement in MCL patients. Treatments aimed at preventing this complication are warranted.

Clinical significance of monoclonal B cells in cerebrospinal fluid.

BACKGROUND: Morphologically malignant lymphocytes in the cerebrospinal fluid (CSF) are highly suggestive of central nervous system involvement by lymphoid malignancy. Although flow cytometry is increasingly used to detect a monoclonal B-cell population in the CSF, the significance of this finding in the absence of morphologically identifiable malignant cells is unknown. METHODS: We reviewed CSF flow cytometric results in 32 patients studied at a single institution over 5 years and identified patients who had monoclonal B-cells in the CSF. Clinical presentation and course were reviewed. RESULTS: Twelve patients had a monoclonal B-cell population in the CSF, but only three had clinical evidence of malignant CNS disease. Of the other nine patients, 4 had nonmalignant neurologic disease and five had a lymphoproliferative disorder: chronic lymphocytic leukemia (n = 4) and mantle cell lymphoma (n = 1). In patients who had chronic lymphocytic leukemia and mantle cell lymphoma, the monoclonal B-cell population was small and had an immunophenotype identical to that of circulating malignant B cells. None of these nine patients developed clinical evidence of malignant CNS involvement during follow-up. CONCLUSION: In patients who have indolent B-cell malignancies, the presence of monoclonal B cells in the CSF may not be diagnostic of clinically significant CNS involvement by a lymphoid malignancy.

Cerebrospinal fluid involvement in mantle cell lymphoma.

Mantle cell lymphoma (MCL) is an aggressive neoplasm that is incurable by standard therapy. Patients often present with high-stage disease (Stages III-IV) and frequently have involvement at multiple extranodal sites. Although the gastrointestinal tract, spleen, lung, pleura, bone marrow, and peripheral blood are among the most commonly involved tissues, MCL may also disseminate to so-called sanctuary sites including the central nervous system. Despite this, current clinical evaluations do not routinely include assessment of the cerebrospinal fluid (CSF) for lymphomatous infiltrates at presentation, and moreover, only few authors have specifically examined CSF involvement in MCL. In this study, we reviewed the medical records of 108 patients with MCL seen at three centers over a 5-year period to determine the rate of CSF sampling and the frequency of CSF involvement by MCL. The clinical and cytologic characteristics associated with CSF involvement were also studied. Central nervous system (CNS) signs and/or symptoms prompted CSF sampling in 25/108 patients (23%). Specific radiographic abnormalities were present in 9/25 patients (36%). CSF involvement by MCL was identified in 10 of the 25 CSF-sampled patients (40%) by morphology (3 patients), flow cytometry alone (1 patients), or both (6 patients). The CSF-positive cases included two blastoid variants. The CSF cytology of the nine morphologically positive cases was pleomorphic, and prominent cytoplasmic granules were observed in two cases. The overall rate of CSF involvement by MCL among the cohort was 9%, which is comparable to that reported in other selected studies examining this issue.