PMC2822257_01
Preoperative pure tone audiometry shows conductive hearing loss on the left ear (10/70 dB). Right ear is normal (7/10 dB).
jkms-19-155-g001.jpg
PMC2822257_01_jkms-19-155-g001.jpg
F1
Pure tone audiometry showed conductive hearing loss on the left ear (Fig. 1).
Coronal (A, B) and axial (C, D) computed tomography demonstrate a mass-like lesion with soft tissue density occupying the middle ear and mastoid cavity of the left ear (B, D).
jkms-19-155-g002.jpg
PMC2822257_01_jkms-19-155-g002.jpg
F2
Bony erosions were suspected in tegmen tympani and long process of incus of the left ear (Fig. 2).
Histologic features of the lesion. (A) The lesion is composed of exclusively mature disorganized glial tissue and fibrovascular elements in a rather loose fibrillary background. (B) Distended glandular structures are noted at the periphery of the glial tissue (H&E, x100).
jkms-19-155-g003.jpg
PMC2822257_01_jkms-19-155-g003.jpg
F3
The lesion consisted of exclusively mature, disorganized glial tissue with fibrovascular tissue in a rather loose fibrillary background (Fig. 3A). Small distended glands, lined by ciliated, flat or cuboidal epithelium, were present at the periphery of the lesion (Fig. 3B).
Immunohistochemical features. The lesion shows diffuse positive reaction for GFAP (A) and S100 protein (B) (x100).
jkms-19-155-g004.jpg
PMC2822257_01_jkms-19-155-g004.jpg
F4
The glial tissue revealed diffuse positive reaction for GFAP (Fig. 4A) and S100 protein (Fig. 4B), but negative reaction for MAP-2 and CK.