Sphenoid wing lymphoplasmacyte-rich meningioma with occasional emperipolesis closely simulating an intracranial Rosai-Dorfman disease: a diagnostic dilemma.

In lymphoplasmacyte-rich meningioma (LRM) meningothelial whorls are overshadowed by exuberant infiltration by lymphocytes, plasma cells and few histiocytes. Hence, lesions with lymphoplasmacytic proliferation form the histological differentials. We describe the, to the best of our knowledge, first case of LRM with occasiona emperipolesis, creating a diagnostic dilemma with Rosai-Dorfman disease (RDD), around the region of sphenoid wing. LRM was favored due to the presence of epithelial membrane antigen (EMA) and vimentin positive meningothelial whorls, forming approximately 10% of the tumor tissue. Documentation of such cases may help to understand the importance of inflammatory cells and meningothelial whorls, as a manifestation of host response at the leptomeninges.