Primary central nervous system lymphomas at a tertiary academic hospital in Johannesburg

Primary central nervous system lymphomas (PCNSL) are diffuse large B-cell lymphomas (DLBCL), which affect multiple regions of the neuroaxis, including the brain parenchyma, the orbits, cranial nerves and leptomeninges, without systemic disease. The aim of this study was to review the clinical characteristics as well as the outcome of patients referred to a tertiary academic hospital in Johannesburg (South Africa) with a presumed PCNSL diagnosis based on histology, cerebrospinal fluid (CSF) analysis and neuroimaging.

This retrospective record review at a tertiary academic hospital in Soweto (Johannesburg), included patients aged ≥ 17 years referred with a presumed diagnosis of PCNSL, based on biopsy-confirmed PCNSL, CSF analysis or neuroimaging, between January 2010 and December 2022. Patient characteristics (laboratory, clinical, treatment(s), outcome) were analysed in three groups based on diagnostic certainty for PCNSL (diagnostic, suspicious, consistent).

The cohort comprised 14 patients, with most cases occurring in People Living with Human Immunodeficiency Virus (PLWH) (n = 10; 71%), with equal representation of male and female patients. The median age of diagnosis was 43 years (17-64), with PLWH diagnosed at an earlier mean age of 40 compared to human immunodeficiency virus (HIV)-negative patients (mean age 52). Both surviving patients received between 6 and 8 cycles of high-dose methotrexate (HD-MTX), with one receiving an autologous stem cell transplant. Over half (57%) of the cohort died with a median overall survival of two months (95% CI 1.3-2.6).

Establishing a PCNSL diagnosis without histology often relies on several ancillary investigations. The high mortality and poor median survival highlight the importance of timely diagnosis and treatment.

This case series highlights the the complexities of a PCNSL diagnosis in PLWH and will hopefully inspire future work in this area.