Penetrating Triple-Layer Involvement: Scalp, Skull, and Dura Mater By Follicular Lymphoma -An Unusual Presentation Mimicking Traumatic Meningioma.

The authors report an exceptionally rare case of follicular lymphoma (FL) with simultaneous penetration through the scalp, skull, and dura mater in a 31-year-old female presenting with a progressive scalp mass and a left frontal lesion. Initially misdiagnosed as a traumatic meningioma based on history and imaging (showing a dural-based mass with "dural tail sign" and subgaleal fluid), surgical resection revealed FL with atypical features: BCL2 negativity (suggesting potential aggressiveness), high Ki67 (50%), and diffuse growth invading the dura. This case underscores the importance of including lymphoma, even indolent FL, in the differential diagnosis of lesions spanning scalp, bone, and meninges, especially with atypical features or trauma history.