Tenosynovial giant cell tumor of the bony external auditory canal: a rare extra-articular case managed by transcanal endoscopic excision

Abstract

Tenosynovial giant cell tumour (TGCT) is a benign proliferative lesion arising from synovial-type tissue, most commonly involving small joints of the extremities. Occurrence in the external auditory canal (EAC), particularly the bony canal, is exceedingly rare. We report a 20-year-old male presenting with left-sided aural fullness and conductive hearing loss of one month’s duration. Otoscopy revealed a smooth, pinkish mass arising from the anterosuperior bony EAC and abutting the tympanic membrane. Complete excision was performed using transcanal endoscopic ear surgery. Histopathology with immunohistochemistry supported localized TGCT. Postoperatively, canal patency was restored, hearing normalized, and no recurrence was observed. This case highlights the diagnostic challenge of EAC giant cell-rich lesions and supports endoscopic excision as an effective treatment.