Primary Dural-based diffuse large B-cell lymphoma mimicking meningioma in the olfactory groove: An unique case report and brief review of the literature.

Primary central nervous system lymphomas (PCNLs) are malignant non-Hodgkin lymphomas solely affecting the central nervous system (CNS). Primary dural lymphoma, which is rare in the CNS, has not been previously reported in a study of the olfactory groove. We present the clinical course of a 77-year-old immunocompetent male who presented with nonspecific symptoms of fatigue and transient memory loss. Although the patient's neurological examination was unremarkable, cranial imaging identified a lesion highly suspicious for an olfactory groove meningioma. Consequently, the patient underwent a bifrontal craniotomy; however, intraoperative exploration proved incongruent with imaging as no distinct mass was identified. While the immediate postoperative recovery was uneventful, the patient experienced significant clinical deterioration 1 month later, necessitating admission to the intensive care unit. Subsequent histopathological analysis of the biopsy specimen provided the definitive diagnosis of primary dural-based diffuse large B-cell lymphoma (DLBCL), and comprehensive staging with FDG-PET and contrast-enhanced CT confirmed the disease was confined strictly to the CNS. This case underscores the importance of considering primary dural lymphoma in the differential diagnosis of anterior skull base lesions even when imaging mimics meningioma, and highlights the essential role of histological confirmation in navigating such diagnostic complexities.