OP23. T cell expression in CNS lymphomas: A single centre experience of Primary CNS T-Cell Lymphomas

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General Surgery (East Africa)


INTRODUCTION: Primary CNS lymphomas (PCNSLs) are a rare entity and comprise only 5% of brain tumours. Histopathologically they are primarily of B-cell phenotype. Primary CNS T-Cell Lymphomas (PCNSTLs) constitute <5% of all PCNSLs. Such rarity in clinical practice means there is a paucity of robust data on the long term outcomes for patients with PCNSTLs. We report our PCNSTL (or T-Cell rich PCNSLs) experience over 7 years. METHODS: We reviewed our pathology database for all PCNSLs diagnosed between 2009 and 2016. Specifically T-cell expression, Ki67 Proliferative Index (KPI) and CD expression were looked reviewed from histopathological reports. Treatment options, survival and complications were also reviewed. RESULTS: We identified a total of 58 PCNSLs of which 2 were pure T-cell lymphomas and 3 were B cell lymphomas with T cell expression (2 were ‘T-cell rich’; 1 was anaplastic). Mean age was 58.4 (44–66 years). These 5 patients comprised of 4 males and 1 female. One patient was HIV positive; and another had a previous history of lung cancer. On FLAIR MR Imaging, three patients had supratentorial bihemispheric lesions; and one patient (who is still alive) had a left cerebellar lesion. In our small sample, those with bihemispheric lesions had shorter survival times which would correlate with extent of disease dissemination within the white matter tracts. The 2 ‘T-cell rich’ samples had a KPI of 70–80%. (In the PCNSLs with T cell expression, the KPI ranged from 20% - 90% and in our group this correlated with survival).One patient whose cells demonstrated a KPI of 90% survived for only 56 days from diagnostic biopsy. Immunohistochemistry showed variable CD expression (as in previous published literature). All 5 patients had their histology dually reported by a neuropathologist and haemotopathologist. One patient was not fit enough for oncology treatment. The other 4 had chemotherapy and all had relapses or progression on treatment. Mean survival time was 275.2 days (7.56months with a range of 56–571 days). At the time of writing, 1 patient was still alive with ongoing haematology clinic review; 1 was discharged to a palliative care facility and 3 patients had died. SUMMARY: With PCNSTls or PCNSLs with T-cell expression, there seems to be an association between survival and the Ki67 proliferative index in addition to presence of bilateral supratentorial disease on MR imaging. As they are extremely rare presentations, further studies would perhaps benefit from multi-centre involvement. Their histological diagnosis (especially immunohistochemistry) remains challenging due to the heterogeneity of the cells and CD expression, and in our experience has often required multiple histology reviews.

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Creative Commons Attribution 4.0 International License
This work is licensed under a Creative Commons Attribution 4.0 International License.