Korean J Pathol.
1997 Jul;31(7):688-691.
Cellular Schwannoma Arising in a Facial Nerve
- Affiliations
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- 1Department of Pathology, Seoul Paik Hospital, Inje University, Seoul 100-032, Korea.
- 2Department of Otolaryngology, Seoul Paik Hospital, Inje University, Seoul 100-032, Korea.
Abstract
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Cellular schwaninoma is a variant of schwannoma, which is characterized by predominance of cellular Antoni A area, presence of mitotic activity, nuclear hyperchromasia, pleomorphism, and absence of Verocay body. These pathologic features often prompted a misdiagnosis of malignancy. However, the clinical outcome has indicated the benignity of the tumor. We have experienced a case of cellular schwannoma arising from right facial nerve with right hemifacial weakness and erosion of mastoid process. Grossly, it was a 3.5 x 3 cm sized and relatively well encapsulated mass with yellowish, friable cut surface. Microscopically, cellular growth with moderate cellular pleomorphism and some mitotic activity (5/40 HPFS, up to 2/HPF) were noted. Immunostaining for S-100 protein showed diffuse strong positive reaction.