The most common tumor that spread to orbit from intracranial cavity is
**Core Concept**
The question is testing the understanding of the most common intracranial tumor that metastasizes to the orbit, which is a rare but significant clinical entity. This requires knowledge of the anatomical relationships between the intracranial structures and the orbit.
**Why the Correct Answer is Right**
The most common intracranial tumor that spreads to the orbit is the **meningioma**. Meningiomas are typically benign tumors arising from the meninges, the protective membranes surrounding the brain and spinal cord. They can arise from the sphenoid wing, olfactory groove, or other locations near the orbit. When meningiomas grow, they can invade the surrounding structures, including the optic nerve, leading to visual disturbances and other symptoms. The close proximity of the sphenoid wing to the orbit makes meningiomas a common cause of orbital invasion.
**Why Each Wrong Option is Incorrect**
* **Option A:** Meningiomas are more common than other intracranial tumors like gliomas and metastatic tumors in spreading to the orbit.
* **Option B:** Chordomas are rare bone tumors that can arise from the clivus and can affect the orbit, but they are not the most common intracranial tumor to do so.
* **Option D:** Craniopharyngiomas are rare tumors that arise from the pituitary stalk and can affect the optic chiasm, but they are not the most common intracranial tumor to spread to the orbit.
**Clinical Pearl / High-Yield Fact**
When evaluating a patient with a mass in the orbit, it's essential to consider the possibility of a metastatic tumor, particularly meningioma, especially if the patient has a history of intracranial tumor. A thorough ophthalmological examination, including visual field testing and imaging studies like MRI or CT scans, is crucial for accurate diagnosis and management.
**Correct Answer:** C. Meningioma.