Rare Aggressive Calvarial Osteoblastoma with Dural Invasion.

We report a rare case of an aggressive osteoblastoma (OB) involving the calvaria and infiltrating the dura, a finding that was not previously reported in the literature. A 50-year-old man presented with a progressive mass in the left frontoparietal skull with headaches and a six-month history of sudden mass growth. Computed tomography (CT) and magnetic resonance imaging (MRI) showed a large skull lesion with areas of hemorrhage, calcification, restricted diffusion, and enhancement.  A left temporoparietal craniotomy with a complete resection of the tumor with grossly clean margins was performed. Follow-up at 60 months showed a stable clinical picture and no sign of local recurrence of the lesion on MRI.