Surgical salvage of recurrent T3 nasopharyngeal carcinoma: Prognostic significance of clivus, maxillary, temporal and sphenoid bone invasion.

•The commonest cranial bone involved in recurrent T3 NPC is the pterygoid process.•Bypass should be considered when tumour encases the internal carotid artery.•Outcome of surgery is significantly better with clear resection margins.•Poor prognosis when both cortexes of clivus involved by tumour.•Poor prognosis when lateral wall of sphenoid sinus involved by tumour.