Dural Lymphomas Unmasked: A Narrative Review of Extra-Axial Mimics and a Pragmatic Diagnostic Decision Algorithm

Dural-based lymphomas are rare extranodal non-Hodgkin lymphomas that span from indolent primary dural entities, most commonly the extranodal marginal zone (mucosa-associated lymphoid tissue) lymphoma, to aggressive variants that are primary or represent secondary involvement from systemic lymphoma. They overlap radiologically with benign meningiomas, dural metastases, and immune-mediated pachymeningitis, creating a risk of anchoring bias, delayed diagnosis, and unnecessarily extensive resections when limited tissue sampling would be sufficient for diagnosis. We conducted a structured narrative review to synthesize the epidemiology, clinico-pathological classification, imaging phenotypes, and management principles of dural lymphomatous disease. This study will especially focus on primary dural lymphoma (PDL) with additional discussion of secondary dural involvement. Emphasis is placed on the clinical value of a multiparametric diagnostic approach that integrates computed tomography contrast-enhanced magnetic resonance imaging with functional techniques, and fluorodeoxyglucose positron emission tomography/computed tomography for systemic staging and for distinguishing truly localized primary dural lymphoma from secondary involvement. Potential diagnostic pitfalls related to somatostatin receptor-based tracer uptake will also be discussed. We introduced a pragmatic operational framework based on four clinico-biological clusters, translated into a step-by-step decision algorithm that prioritizes timely biopsy and comprehensive hematologic staging to guide surgical strategy. Given the absence of dedicated, multidisciplinary guidance for dural-based lymphomas, this algorithm is intended as a reproducible foundation for consensus recommendations and future multicenter validation.