**Core Concept**
Pituitary adenomas, particularly craniopharyngiomas, are common causes of visual disturbances and headaches in children due to their location near the optic chiasm. These tumors can cause increased intracranial pressure, leading to symptoms such as headaches and visual disturbances.

**Why the Correct Answer is Right**
Craniopharyngiomas are benign tumors that arise from the remnants of Rathke's pouch, which is a precursor to the anterior pituitary gland. They are typically located near the optic chiasm and can cause visual disturbances due to compression of the optic nerves or chiasm. The increased intracranial pressure associated with craniopharyngiomas can also lead to headaches and other symptoms.

**Why Each Wrong Option is Incorrect**
**Option A:** **Meningioma** - Meningiomas are typically slow-growing tumors that arise from the meninges, the protective membranes surrounding the brain and spinal cord. While they can cause visual disturbances and headaches, they are less common in children than craniopharyngiomas.
**Option B:** **Optic neuritis** - Optic neuritis is an inflammation of the optic nerve that can cause visual disturbances, but it is not typically associated with headaches or increased intracranial pressure.
**Option C:** **Cerebral vasculitis** - Cerebral vasculitis is an inflammation of the blood vessels in the brain that can cause headaches and visual disturbances, but it is a less common cause of these symptoms in children.

**Clinical Pearl / High-Yield Fact**
Craniopharyngiomas are often associated with calcification on imaging studies, which can help distinguish them from other types of tumors.

**Correct Answer:** C. Cerebral vasculitis