**Question:** True about meningiomas -

A. Meningiomas are the most common primary brain tumor
B. Meningiomas are benign tumors
C. Meningiomas are malignant tumors
D. Meningiomas are exclusively located in the pituitary gland

**Core Concept:** Meningiomas are a type of primary brain tumor that originate from the arachnoid cells, which line the brain and spinal cord. These tumors can affect individuals of all ages and genders. Meningiomas consist of two types: benign (usually WHO grade I) and malignant (WHO grade II or III).

**Why the Correct Answer is Right:** Meningiomas are indeed the most common primary brain tumor, accounting for approximately 30-40% of all intracranial tumors. They are classified as benign (WHO grade I) tumors due to their slow growth rate, limited infiltration, and low rate of recurrence after surgical excision.

**Why Each Wrong Option is Incorrect:** Option C is incorrect as meningiomas are primarily benign (non-malignant) tumors. Option D is incorrect because meningiomas develop from the arachnoid cells lining the brain and spinal cord, not exclusively from cells in the pituitary gland.

**Clinical Pearl:** Meningiomas are often asymptomatic initially, leading to a delay in diagnosis. However, when symptomatic, they may cause various neurological deficits depending on their location, such as visual disturbances, cranial nerve palsies, and seizures. A comprehensive evaluation, including imaging studies, is essential for accurate diagnosis and treatment planning.

**Correct Answer:** **B. Meningiomas are benign tumors.**