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Author Spotlight: Unveiling Cellular Functions and Potential Clinical Implications of Leptomeningeal Lymphatic Endothelial Cells
Published on: September 8, 2023
Primary leptomeningeal lymphoma: International Primary CNS Lymphoma Collaborative Group report
Jennie W Taylor1, Eoin P Flanagan, Brian P O'Neill
1From the Massachusetts General Hospital (J.W.T., T.B., R.A.B.), Boston; Mayo Clinic (E.P.F., B.P.O.), Rochester, MN; Hadassah Hebrew University Medical Center (T.S.), Jerusalem, Israel; Memorial Sloan-Kettering (A.O., L.D.), New York, NY; Yale University (J.B.), New Haven, CT; Saitama Medical University (R.N.), Japan; Kings College Hospital (F.P.), London, UK; University of Washington (M.C.), Seattle; LOC National Expert Center (K.H.-X., A.G.-A.), APHP, UPMC, Pitie-Salpetriere, Paris; Centre Leon Berard (J.-Y.B.), Lyon, France; Campus Benjamin Franklin (A.K.), Charite Universitätsmedizin Berlin, Germany; Department of Biostatistics (R.A.B.), Harvard School of Public Health, Boston, MA; and University of Virginia (M.-B.S.L., D.S.), Charlottesville.
Objective:
To evaluate clinical presentation, optimal diagnostic evaluation and treatment, and outcome in primary leptomeningeal lymphoma, a rare form of primary CNS lymphoma without parenchymal or systemic involvement.
Methods:
The International Primary CNS Lymphoma Collaborative Group, a multidisciplinary group of physicians with a particular interest in primary CNS lymphoma, retrospectively identified cases of lymphoma isolated to the leptomeninges as diagnosed by CSF cytology, flow cytometry, or biopsy, without systemic or parenchymal brain/spinal cord lymphoma or immunodeficiency.
Results:
Forty-eight patients were identified, with median age at diagnosis of 51 years and median Eastern Cooperative Oncology Group performance status of 2. Presenting symptoms were multifocal in 68%. Leptomeningeal enhancement was seen in 74% and CSF profile was abnormal in all cases. CSF cytology detected malignant lymphocytes in 67%. Flow cytometry identified monoclonal population in 80%, as did receptor gene rearrangement studies in 71%. Sixty-two percent had B-cell lymphoma, 19% T-cell, and 19% unclassified. Treatment varied and included fractionated radiotherapy (36%), systemic chemotherapy (78%), and intra-CSF chemotherapy (66%), with 66% receiving ≥ 2 modalities. Seventy-one percent had a favorable clinical response; ultimately, 44% received salvage treatment. Median overall survival was 24 months, with 11 patients still alive at 50 months follow-up.
Conclusion:
Primary leptomeningeal lymphoma is a rare form of primary CNS lymphoma. Patients usually present with multifocal symptoms, with evidence of leptomeningeal enhancement and diagnostic CSF analysis. Although treatment is highly variable, patients have a better prognosis than previously reported and a subset may be cured.
