Primary central nervous system mucosa-associated lymphoid tissue lymphoma: a diagnostic challenge.

Primary central nervous system (CNS) mucosa-associated lymphoid tissue (MALT) lymphoma is a rare condition frequently mistaken for meningioma. Since these conditions require distinct treatment approaches, recognizing their imaging characteristics is essential for accurate clinical decision-making. A 69-year-old woman presented with headaches and forehead swelling, prompting MRI of the CNS. Suspecting an intracranial meningioma, the tumour board recommended surgical resection. However, histopathological analysis identified the lesion as a primary CNS MALT lymphoma. Follow-up revealed secondary cutaneous tumour infiltration, leading to a delay in adjuvant radiotherapy. Understanding the differential diagnoses of meningioma is critical for neuroradiologists and neurosurgeons to ensure appropriate treatment planning. This case highlights a misdiagnosis of meningioma that was ultimately identified as a primary CNS MALT lymphoma, emphasizing key imaging and clinical characteristics essential for distinguishing between the most important differential diagnoses of primary CNS MALT lymphoma.