AB021. Primary diffuse large B-cell lymphoma of the central nervous system: role of imaging in a rare disease—a case report

Background: Primary diffuse large B-cell lymphoma (DLBCL) of the central nervous system (CNS) constitutes approximately 1–3% of primary CNS tumors. This rare CNS tumor presents diverse clinical manifestations and variable imaging characteristics, making its diagnosis challenging using radiological modalities alone. Recognizing the role of imaging in different stages of treatment and understanding the various imaging patterns and radiological features is crucial for timely diagnosis and appropriate therapeutic decision-making.

Case Description: A 62-year-old woman presented to our tertiary hospital with a 1-month history of left-sided headache and left hemiparesis. A computed tomography (CT) scan from a previous hospital revealed a space-occupying lesion in the right temporo-occipital region with signs of increased intracranial pressure but no evidence of hemorrhage or calcifications. Subsequent magnetic resonance imaging (MRI) demonstrated a solid intra-axial lesion in the right temporoparietooccipital region, which exhibited heterogeneous enhancement with diffusion restriction. The lesion appeared hypointense on T1-weighted and hyperintense on T2-fluid attenuated inversion recovery (T2-FLAIR) sequence, containing cystic components surrounded by edema and causing compression of the occipital horn of the right lateral ventricle without midline shift. Immunohistochemical analysis confirmed the diagnosis of high-grade DLCBL. The patient underwent surgical resection followed by chemotherapy. A follow-up MRI revealed a new lesion in the right temporoparietooccipital region, which had increased in size, suggestive of lymphoma recurrence. The variable radiological presentations of primary CNS lymphoma (PCNSL) can often mimic other pathologies, such as gliomas, infections, abscesses, and secondary lymphomas, making it a diagnostic challenge. The imaging findings in this case align with the typical features of PCNSL. Both initial and follow-up imaging played a crucial role in guiding therapeutic decisions and assessing treatment response.

Conclusions: This case report underscores the importance of recognizing the imaging characteristics of primary DLBCL of the CNS. Timely and accurate diagnosis based on imaging patterns is essential for expediting therapeutic decisions and evaluating the efficacy of treatment interventions, ultimately improving patient outcomes.

Keywords: Lymphoma; radiology; primary central nervous system lymphoma (PCNSL); imaging; case report