**Question:** Which of the following tumors is not derived from meninges -

A. Meningioma (meninges-derived)
B. Glioblastoma (brain parenchyma-derived)
C. Medulloblastoma (brain stem-derived)
D. Astrocytoma (brain parenchyma-derived)

**Correct Answer: B. Glioblastoma (brain parenchyma-derived)**

**Core Concept:** Meningiomas are tumors derived from meningeal cells, specifically arachnoid cells lining the brain and spinal cord. They are benign (grade I or II) tumors that can affect the meninges, leading to symptoms related to tumor size, location, and compression of surrounding structures.

**Why the Correct Answer is Right:** Glioblastoma, on the other hand, is a malignant (grade IV) tumor originating from glial cells within the brain parenchyma, not the meninges. These tumors typically present with symptoms related to mass effect, invasion, and disruption of brain function.

**Why Each Wrong Option is Incorrect:**

A. Meningiomas (meninges-derived) are indeed related to the meninges and can present with symptoms related to their location and mass effect.

B. Glioblastomas are parenchyma-derived, not meninges-derived. They are not associated with the meninges.

C. Medulloblastomas are tumors of the brain stem, not derived from the meninges. While they may present with cerebellar symptoms, they are not meninges-derived.

D. Astrocytomas, like glioblastomas, are parenchyma-derived, not meninges-derived. They are not associated with the meninges.

**Clinical Pearl:** Understanding the embryological and histopathological origin of tumors is crucial for accurate diagnosis, treatment planning, and prognosis. Differentiating meninges-derived tumors from parenchyma-derived tumors is essential in neuropathology and clinical practice.