**Core Concept**
Pseudorosettes are a type of cellular arrangement seen in certain neoplasms, characterized by a central area of cells surrounded by a palisade of cells, resembling a rosette. This pattern is often observed in tumors with neuroectodermal differentiation.

**Why the Correct Answer is Right**
Pseudorosettes are typically seen in medulloblastoma, a type of primitive neuroectodermal tumor (PNET) that originates in the cerebellum. The formation of pseudorosettes in medulloblastoma is thought to be due to the radial arrangement of tumor cells around a central area of neuropil, which is the network of nerve fibers and supporting cells. This pattern is a result of the tumor cells' attempt to mimic the normal architecture of the developing nervous system.

**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect as pseudorosettes are not a characteristic feature of glioblastoma, a type of primary brain tumor that arises from astrocytes. While glioblastoma can exhibit a range of histological patterns, pseudorosettes are not a typical feature.
* **Option B:** This option is incorrect as pseudorosettes are not a characteristic feature of meningioma, a type of tumor that arises from the meninges, the protective membranes surrounding the brain and spinal cord.
* **Option C:** This option is incorrect as pseudorosettes are not a characteristic feature of ependymoma, a type of tumor that arises from the ependymal cells lining the ventricles and central canal of the spinal cord.

**Clinical Pearl / High-Yield Fact**
When evaluating a brain tumor, it's essential to recognize the characteristic histological patterns, including pseudorosettes, to determine the tumor's origin and make an accurate diagnosis. Familiarity with these patterns can aid in differentiating between various types of brain tumors and guide treatment decisions.

**Correct Answer:** D.