BACKGROUND
Granular cell tumor (GCT) is a benign neoplasm composed of a proliferation of round or polygonal cells that contain eosinophilic granular cytoplasm. The most common locations are tongue and subcutaneous tissue, but a variety of other sites may be involved including the central nervous system (CNS). Most CNS GCT arise in the pituitary, but rare cases involving brain and leptomeninges have been described. Extracranial GCT are usually S-100-positive, but those of the CNS, as well as the congenital variant of GCT, can be S-100-negative.
CASE REPORT
We report an incidental autopsy finding of a 2.5 mm GCT that arose in the intracranial meninges overlying the anterior superior cerebellar vermis.
RESULTS
The neoplasm had abundant eosinophilic, granular cytoplasm that was PAS-positive and diastase-resistant. Immunohistochemical studies showed that the neoplasm was positive for CD68 and negative for S-100, GFAP, EMA, and keratin. Thus, the immunophenotype is consistent with non-neural origin.
CONCLUSION
Although this lesion in this circumstance was of no clinical significance, knowledge of the occurrence of GCT at this site broadens the differential diagnosis of eosinophilic lesions of the leptomeninges.