Real-world challenges in primary central nervous system lymphoma: a case series.

backgroundPrimary central nervous system lymphoma (PCNSL) belongs to the group of the large B-cell lymphomas of immune-privileged sites, confined to the central nervous system. Its heterogeneous clinical and radiological presentation often leads to diagnostic delay, particularly in non-specialized centers. This study aimed to characterize the clinical, demographic, imaging, and treatment-related features of patients diagnosed with PCNSL in a tertiary hospital without the needed facilities to manage these patients and to highlight associated diagnostic challenges.

methodsWe performed a retrospective, descriptive, single-centre study including patients diagnosed with histologically confirmed PCNSL between February 2011 and December 2022. Clinical, laboratory, imaging, histology of brain biopsy, treatment, and survival data were collected and analysed. Survival time was defined as the interval from diagnosis to death, and symptom-to-diagnosis time as the interval from symptom onset to pathological confirmation.

resultsTwenty-two patients were included (median age 65 years), most of whom were immunocompetent (82%). Neuropsychiatric symptoms and focal neurological deficits were the most common presentations. Imaging revealed predominantly supratentorial (82%) and multifocal (68%) lesions, with homogeneous gadolinium enhancement in most cases and universal diffusion restriction on MRI. Atypical imaging patterns, including ring enhancement in immunocompetent patients, were observed. Histological confirmation was achieved in 21 cases; cerebrospinal fluid flow cytometry was diagnostic in only two patients with spinal or leptomeningeal involvement. Median symptom-to-diagnosis interval was 2.5 months. Younger patients (< 50 years) had longer diagnostic delays but significantly longer survival. Patients receiving targeted therapy had significantly longer median survival than those receiving palliative care (7 vs. 1 month). Overall median survival was 2 months, and six-month mortality was 54.5%.

conclusionPCNSL remains a major diagnostic challenge, particularly in non-specialized hospitals, due to its clinical and radiological heterogeneity. Early suspicion, prompt biopsy, and timely referral to specialized centers are crucial to improve outcomes. Although limited by the small sample size and retrospective design, this study provides relevant real-world data highlighting the impact of diagnostic delay and treatment access on survival.