Tumoral Mimics of Subdural Hematomas: Case Report and Review of Diagnostic and Management Strategies in Primary B-Cell Lymphoma of the Subdural Space.

Background: Subdural lymphomas are a rare subtype of primary central nervous system lymphomas that can radiographically mimic epidural blood and pose a diagnostic challenge. They can complicate treatment if not preemptively identified.

Methods: We present a case report of a subdural lymphoma that mimicked a compressive subdural hematoma, and we review the PubMed database for similar cases.

Results: A 77-year-old woman presented with a transient left facial droop and what appeared to be a subdural hematoma on computed tomography scan. The patient underwent surgery, during which grossly abnormal solid epicortical adherent tissue was noted instead of the expected appearance of a subdural hematoma. An intraoperative biopsy was suggestive of lymphoma, and the surgery was converted to a craniectomy. Pathology confirmed the diagnosis of extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue. The patient underwent radiotherapy with no complications or recurrence. Magnetic resonance imaging demonstrated complete resolution of the mass at 3 months after treatment, at which time the patient underwent a synthetic cranioplasty. Seven case reports of primary dural lymphomas mimicking subdural blood were found, with variable pathologic subclassifications.

Conclusions: Although rare, a primary dural lymphoma can be mistaken for a subdural hematoma on computed tomography scan. The most common subtype is low-grade extranodal marginal zone lymphomas. It is important to keep these diseases in the differential diagnosis, especially when there is incongruence between imaging and the clinical picture, as earlier detection correlates to a stronger therapeutic response.