Differential Diagnosis for En Plaque Meningioma vs. Hemangiopericytoma

When differentiating between en plaque meningioma and hemangiopericytoma, it's crucial to consider various factors including imaging characteristics, clinical presentation, and histopathological features. Here's a structured approach to the differential diagnosis:

• Single Most Likely Diagnosis

  • Meningioma: Given the description of "en plaque," which refers to a variant of meningioma that grows in a flat, sheet-like manner along the surface of the brain, often involving the dura mater. This pattern is more typical of meningiomas, especially the en plaque subtype, which can mimic the appearance of hemangiopericytoma on imaging but is generally more common.

• Other Likely Diagnoses

  • Hemangiopericytoma: A rare tumor that can present similarly to meningioma on imaging, with dural attachment and sometimes a similar appearance on MRI or CT scans. However, hemangiopericytomas tend to be more vascular and may have a more aggressive clinical course.
  • Solitary Fibrous Tumor/Hemangiopericytoma (now considered under the same category by the WHO): These tumors can also present with dural attachment and may mimic meningiomas in their imaging characteristics. They are known for their slow growth and potential for local recurrence.

• Do Not Miss Diagnoses

  • Metastatic Disease: Although less likely, metastatic lesions to the dura or brain surface can mimic both meningiomas and hemangiopericytomas. Missing a diagnosis of metastatic disease could have significant implications for treatment and prognosis.
  • Lymphoma: Primary central nervous system lymphoma (PCNSL) can occasionally present with dural involvement and may mimic other dural-based lesions. Given its aggressive nature and different treatment approach, it's crucial not to miss this diagnosis.

• Rare Diagnoses

  • Sarcomas: Rarely, sarcomas (such as osteosarcoma, chondrosarcoma, or others) can present with dural involvement and may be considered in the differential diagnosis, especially if there are characteristic imaging features or a relevant clinical history.
  • Melanocytic Tumors: Melanocytic lesions, including melanocytomas or malignant melanomas, can rarely involve the dura and may enter the differential diagnosis based on specific imaging characteristics or clinical context.

Each diagnosis should be considered in the context of the patient's overall clinical presentation, imaging findings, and histopathological examination when available. The differentiation between these entities often requires a combination of MRI characteristics, clinical behavior, and ultimately, histological confirmation.