Neuropathology Practice Questions

Q: Which of the following conditions classically shows a rosette-shaped arrangement of cells?

Ependymoma. **Explanation:** The correct answer is **Ependymoma**. In pathology, a "rosette" refers to a circular or flower-like arrangement of cells. Ependymomas are neuroepithelial tumors that classically exhibit two types of rosette formations [1]: 1. **Perivascular Pseudorosettes:** Tumor cells are arranged around a central blood vessel, separated by a fibrillary zone (cytoplasmic processes) [1]. This is a hallmark feature found in almost all ependymomas. 2. **True Ependymal Rosettes (True Rosettes):** Tumor cells surround a central lumen (resembling a small duct), mimicking the structure of the central canal of the spinal cord [1]. **Analysis of Incorrect Options:** * **A. Thecoma of ovary:** These are sex cord-stromal tumors composed of spindle-shaped cells with lipid-laden cytoplasm. They typically show a diffuse or fascicular growth pattern, not rosettes. * **C. Neurofibroma:** These are peripheral nerve sheath tumors characterized by a "shredded carrot" appearance due to wavy collagen bundles and spindle cells in a myxoid background. * **D. Lymphoma:** Malignant lymphomas generally present as a diffuse sheet of discohesive, monomorphic round cells. They do not form organized architectural patterns like rosettes. **High-Yield Clinical Pearls for NEET-PG:** * **Homer Wright Rosettes:** Cells surround a central fibrillary core (no lumen/vessel). Seen in **Neuroblastoma**, Medulloblastoma, and Retinoblastoma. * **Flexner-Wintersteiner Rosettes:** Cells surround a central lumen. Highly specific for **Retinoblastoma**. * **Call-Exner Bodies:** Small follicles filled with eosinophilic material, seen in **Granulosa Cell Tumors** (often confused with rosettes). * **Ependymoma Location:** Most common in the fourth ventricle in children and the spinal cord in adults [1]. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Central Nervous System, pp. 1312-1313.

Q: Cowden syndrome is associated with which of the following findings?

Dysplastic gangliocytoma. **Explanation:** **Cowden Syndrome** (Multiple Hamartoma Syndrome) is an autosomal dominant disorder caused by a mutation in the **PTEN gene** on chromosome 10q23. PTEN is a tumor suppressor gene that inhibits the PI3K/AKT/mTOR pathway. **Why the correct answer is right:** The pathognomonic CNS manifestation of Cowden syndrome is **Lhermitte-Duclos Disease (LDD)**, also known as **Dysplastic Gangliocytoma of the cerebellum**. It is a rare, slowly progressing tumor characterized by the replacement of the internal granular layer of the cerebellum with large, dysplastic ganglion cells. On MRI, it classically presents as a "tiger-striped" cerebellar mass. **Why the incorrect options are wrong:** * **Medulloblastoma:** While associated with familial syndromes like **Gorlin syndrome** (PTCH1 mutation) [1] and **Turcot syndrome** (APC mutation), it is not a feature of Cowden syndrome. * **Astrocytoma:** These are common primary brain tumors but are more typically associated with **Neurofibromatosis type 1 (NF1)** and **Li-Fraumeni syndrome** (TP53). * **PNET:** These aggressive embryonal tumors are not specifically linked to the PTEN mutation or Cowden syndrome. **High-Yield Clinical Pearls for NEET-PG:** * **PTEN Hamartoma Tumor Syndrome (PHTS):** Includes Cowden syndrome and Bannayan-Riley-Ruvalcaba syndrome. * **Associated Malignancies:** Patients have a significantly increased risk of **Breast cancer** (most common), **Follicular Thyroid cancer**, and **Endometrial cancer**. * **Mucocutaneous findings:** Trichilemmomas (benign hair follicle tumors) and oral papillomas are hallmark diagnostic features. * **Lhermitte-Duclos Disease** is now considered a Grade I WHO tumor and is often the first clinical sign leading to a Cowden syndrome diagnosis. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Neoplasia, pp. 306-307.

Question 1

Which of the following conditions classically shows a rosette-shaped arrangement of cells?

Accepted Answer

Ependymoma

Answer

Thecoma of ovary

Answer

Neurofibroma

Answer

Lymphoma

Question 2

Rosettes are not seen in which of the following conditions?

Accepted Answer

Neurocysticercosis

Answer

Retinoblastoma

Answer

Medulloblastoma

Answer

Primitive neuroectodermal tumor (PNET)

Question 3

Verocay bodies are seen in which of the following tumors?

Accepted Answer

Schwannoma

Answer

Meningioma

Answer

Glioma

Answer

Medulloblastoma

Question 4

Dumbbell tumors are characteristic of which of the following neoplasms?

Accepted Answer

Neurofibroma

Answer

Meningioma

Answer

Ependymoma

Answer

Thymoma

Question 5

Negri bodies are characteristically seen in which of the following anatomical locations?

Accepted Answer

Hippocampus

Answer

Hypothalamus

Answer

Medulla

Answer

Midbrain

Question 6

Cowden syndrome is associated with which of the following findings?

Accepted Answer

Dysplastic gangliocytoma

Answer

Medulloblastoma

Answer

Astrocytoma

Answer

Primitive neuroectodermal tumor (PNET)

Question 7

Which type of glial cell is commonly found to be malfunctioning in Alzheimer's disease?

Accepted Answer

Microglia

Answer

Radial glia

Answer

Dendrites

Answer

Oligodendrocytes

Question 8

Shearing damage is seen in which of the following organs?

Accepted Answer

Brain

Answer

Heart

Answer

Liver

Answer

Spinal cord

Question 9

Brain space-occupying lesions cause death by what mechanism?

Accepted Answer

Brain herniation

Answer

Acute hypertension

Answer

Cushing syndrome

Answer

Hypotension

Question 10

Which of the following is NOT associated with antibody-mediated paraneoplastic syndromes?

Accepted Answer

Necrotizing myelopathy

Answer

Stiff person syndrome

Answer

Limbic encephalopathy

Answer

Eaton Lambert syndrome

Neuropathology — MCQs

Neuropathology — MCQs

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