A 45 yr old female complains of progressive lower limb weakness, spasticity, urinary hesitancy. MRI shows intradural enhancing mass lesion. MOST likely diagnosis is:
### **Core Concept**
A meningioma is a type of intracranial tumor arising from the meninges, the protective membranes surrounding the brain and spinal cord. Meningiomas are known for their slow growth and often present with symptoms related to compression of adjacent neural structures.
### **Why the Correct Answer is Right**
The intradural enhancing mass lesion on MRI, combined with the patient's symptoms of progressive lower limb weakness, spasticity, and urinary hesitancy, is highly suggestive of a meningioma. Meningiomas often arise from the dura mater, the outermost meningeal layer, and can compress or invade adjacent neural structures, leading to a range of neurological symptoms. The enhancing nature of the lesion on MRI is also characteristic of meningiomas, as they often have a rich blood supply and can demonstrate contrast enhancement on imaging studies.
### **Why Each Wrong Option is Incorrect**
**Option A:** Dermoid cysts are a type of benign cystic lesion that can occur in the spinal canal, but they typically do not present with the same degree of enhancement as a meningioma on MRI and are less likely to cause significant neurological symptoms.
**Option B:** Intradural lipomas are rare, benign tumors composed of fat tissue that can occur in the spinal canal, but they are not typically associated with the same level of enhancement as a meningioma on MRI and are less likely to cause significant neurological symptoms.
**Option C:** Neuroepithelial cysts are a type of benign cystic lesion that can occur in the spinal canal, but they are not typically associated with the same level of enhancement as a meningioma on MRI and are less likely to cause significant neurological symptoms.
### **Clinical Pearl / High-Yield Fact**
Meningiomas are the most common type of intracranial tumor in adults, and they can occur at any age, but they are more common in women, with a female-to-male ratio of approximately 2:1. They can be divided into several subtypes based on their histological characteristics, with the most common subtype being the meningothelial subtype.
### **Correct Answer Line**
✓ Correct Answer: D. Meningioma