Rosenthal fibres are seen in which of the following tumor?
**Core Concept**
Rosenthal fibers are abnormal intracytoplasmic inclusions found in astrocytes, characteristic of certain pathological conditions, particularly in the context of brain tumors. These fibers are composed of aggregates of intermediate filament proteins, specifically glial fibrillary acidic protein (GFAP).
**Why the Correct Answer is Right**
Rosenthal fibers are commonly associated with pilocytic astrocytomas, a type of low-grade glioma. The presence of these fibers is a diagnostic hallmark of this tumor type, often seen in the cerebellum, particularly in children and young adults. The formation of Rosenthal fibers is thought to be related to the abnormal accumulation of GFAP, which is a key component of astrocytic intermediate filaments.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because Rosenthal fibers are not typically associated with ependymomas, a different type of brain tumor that originates from ependymal cells lining the ventricles and central canal of the spinal cord.
**Option B:** This option is incorrect because while oligodendrogliomas are a type of glioma, they are not characteristically associated with Rosenthal fibers. Oligodendrogliomas are more often linked to the presence of calcifications and perinuclear halo formation.
**Option C:** This option is incorrect because glioblastomas, the most aggressive and malignant type of glioma, do not typically feature Rosenthal fibers as a diagnostic characteristic. Instead, glioblastomas are characterized by their high cellularity, mitotic activity, and necrosis.
**Clinical Pearl / High-Yield Fact**
Remember that Rosenthal fibers are a specific type of inclusion body that can be seen in pilocytic astrocytomas, particularly in the cerebellum of children and young adults. This association can be a helpful diagnostic clue in the context of brain tumor pathology.
**Correct Answer:** C. Pilocytic astrocytoma.