Plasmacytomas occur as lesions in soft tissue or bone. Skull vault plasmacytomas are rare lesions comprising 0.7% of all plasmacytomas. Workup for myeloma must be done in such cases to rule out multiple myeloma. Here, we report a case of a 63-year-old female who presented to us with a large skull vault swelling which appeared to mimic a parasagittal meningioma on imaging. Histopathological imaging revealed it to be a plasmacytoma. A retrospective review of the radiology revealed the characteristic "mini-brain appearance" in our case. Literature on the subject is also reviewed.