Parotid gland involvement in nasopharyngeal carcinoma

Purpose: This study documents the imaging findings of parotid gland involve ment in nasopharyngeal carcinoma (NPC). Method: This study reviewed the film records of 1,916 patients with NPC see n over a 5 year period. There were 27 (1.4%) patients with parotid involvem ent. There were 27 CT and 4 MR studies, and the pattern of involvement was categorized into the following groups: (1) parotid nodal involvement; (2) p arotid invasion from extracapsular cervical nodal spread; (3) direct invasi on by NPC; and (4) diffusely infiltrated gland not related to (2) or (3). Results: In the subset of 27 patients, parotid nodal involvement was seen i n 11 (41%) patients. Ten (37%) patients had cervical extranodal spread into the parotid gland. Three patients (11%) showed direct invasion by NPC, and another three patients (11%) showed an isolated and diffusely infiltrated parotid gland. Conclusion: Metastatic NPC may involve parotid nodes. The parotid gland may also be involved by extracapsular spread from enlarged cervical nodes or i nfiltrated directly by the primary lesion in the nasopharynx.