Lymphoplasmacyte rich meningioma

A.Prof Frank Gaillard et al.

Lymphoplasmacyte-rich meningiomas (LPM) are rare histological variants of benign (WHO grade I) meningiomas, characterized by prominent lymphoplasmacytic infiltrates into the tumor, sometimes rendering the underlying meningothelial component inconspicuous. 

They also have an unusual clinical course (for meningiomas) which instead mimics an inflammatory process 1.  Although reported numbers are few, and thus the features of these tumors have not been firmly established, they appear to differ from conventional meningiomas in a number of ways. 

Unlike the usual meningiomas, lymphoplasmacyte-rich meningiomas are encountered more frequently in somewhat younger patients, without an obvious gender predilection 1

Although the presenting symptom is similar to other intracranial masses (headache - most common, hemiparesis, seizure, dizziness, visual deficits), the course is more acute mimicking an intracranial inflammatory disease. Peripheral blood abnormalities are also detectable, including anemia and polyclonal gammopathy, which normalize following resection 2,4

Although currently considered a variant of meningioma, the exact pathogenesis remains unclear, and whether LPMs arise as tumors or inflammatory masses remains to be elucidated 2. In anycase these masses are characterized by meningothelial tumor cells (appearing similar/identical to a typical meningothelial meningioma) with abundant infiltrating lymphocytes and plasma cells 1,3. Importantly, and supporting the contention that these are actually meningiomas with inflammatory infiltrates is that the inflammatory cells are not monoclonal/neoplastic 3

Due to the relatively few cases reported it is difficult to make dogmatic statements about the imaging features of these tumors. 

In many instances they are solitary, resembling other variants of meningioma, but multiple masses have been reported, including involving the spine 4. They can have extensive relatively flat growth, similar to en plaque meningioma, and may have indistinct margins and vasogenic edema in the adjacent brain parenchyma 5

The differential diagnosis for this rare entity includes:

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Article information

rID: 42380
Synonyms or Alternate Spellings:
  • Lymphoplasmacyte-rich meningiomas (LPM)
  • Lymphoplasmacyte-rich meningiomas

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