Which area of the brain, if impacted by a traumatic intracerebral hemorrhage, warrants immediate surgical intervention due to mass effect?

The posterior fossa is the correct choice because it houses critical structures, including the brainstem, cerebellum, and cranial nerves. An intracerebral hemorrhage in this area can lead to increased intracranial pressure due to the limited space available. The presence of mass effect can quickly compromise vital functions governed by the brainstem, such as respiration and heart rate control.

Immediate surgical intervention is warranted to alleviate the pressure and preserve brain function, which is critical in preventing severe neurological deficits or even death. The need for rapid treatment is underscored by the anatomy of the posterior fossa, where even a small hemorrhage can have significant and immediate consequences due to the enclosed nature of the space.

The other areas mentioned, while they have their own risks if hemorrhaged, do not present the same urgency for surgical evacuation as the posterior fossa, particularly regarding their proximity to the vital structures that regulate essential life functions.