The histopathological image provided demonstrates characteristic features of a central nervous system tumor. Which of the following is the most likely diagnosis?

Explanation

## Image Findings * **Concentric whorls** of tumor cells, where cells are arranged in a spiral pattern. * Presence of **psammoma bodies**, which are laminated, calcified concretions, seen within some of the cellular whorls. * Tumor cells with oval to round nuclei and indistinct, eosinophilic cytoplasm, often appearing in a **syncytial arrangement**. * Overall a relatively uniform cellular population without significant pleomorphism or mitotic activity. ## Diagnosis **Key Point:** The presence of **concentric cellular whorls** and **psammoma bodies** is pathognomonic for **Meningioma**. Meningiomas are typically slow-growing, benign tumors arising from meningothelial cells of the arachnoid mater. Histologically, they are characterized by a syncytial growth pattern, forming characteristic whorls. The presence of psammoma bodies, which are calcified concentric structures, is a highly distinctive feature, particularly common in classic (meningothelial) and secretory meningiomas. The cells often have oval nuclei with finely dispersed chromatin and occasional intranuclear pseudoinclusions (not clearly visible at this magnification but a known feature). ## Differential Diagnosis | Feature | Meningioma | Glioblastoma Multiforme | Schwannoma | Medulloblastoma | |:--------------------|:-------------------------------------------|:-----------------------------------------------|:--------------------------------------------|:----------------------------------------------| | Cell arrangement | Whorls, syncytial growth | Pseudopalisading necrosis, microvascular proliferation | Antoni A (palisading nuclei), Antoni B (loose) | Small round blue cells, Homer-Wright rosettes | | Calcifications | Psammoma bodies (common) | Rare | Rare | Rare | | Nuclear features | Oval, intranuclear pseudoinclusions | Pleomorphic, hyperchromatic, mitotic figures | Spindled, wavy nuclei | Hyperchromatic, scant cytoplasm | | Stroma | Fibrous | Necrotic, vascular | Hyalinized, myxoid | Scant | | Location | Dura-based | Cerebral hemispheres (adults) | Peripheral nerves, cerebellopontine angle | Cerebellum (children) | ## Clinical Relevance **Clinical Pearl:** Meningiomas are the most common primary intracranial tumors in adults, often presenting with symptoms related to mass effect (e.g., seizures, focal neurological deficits) depending on their location. They are typically benign (WHO Grade I) but can recur if incompletely resected. ## High-Yield for NEET PG **High-Yield:** Psammoma bodies are considered a highly characteristic feature of meningiomas, especially the meningothelial and secretory subtypes. **Key Point:** Meningiomas are more common in females and are often associated with NF2 gene mutations. ## Mnemonic **Mnemonic:** Think "**P**sammoma **M**eningioma" to remember the association. ## Common Traps **Warning:** Distinguish meningioma whorls from pseudopalisading necrosis seen in glioblastoma or Verocay bodies in schwannoma. The presence of psammoma bodies is a strong differentiating factor for meningioma. ## Reference [cite:Robbins Basic Pathology, 10th ed. Ch 26, p. 1010-1011]