KIT and cellular schwannoma: Immunohistochemical staining is of great value in the differential diagnosis of this tumor (Table II) (10); the tumor is negative for S-100, glial fibrillary acidic protein (GFAP) and CD57 in the cellular schwannoma, and positive for CK (AE1/AE3), desmin, SMA, CD34, CD117 and discovered on GIST1 (DOG1), with a low positive rate for Ki67.