Parotid Mass

US and CT images of a solid mass in the right parotid gland of an 82-year-old woman who had a painless neck mass for a year.

Facts: Parotid Mass Workup

• Long list of differential possibilities: neoplastic vs. non-neoplastic conditions
• Most helpful test = fine needle aspiration biopsy (accuracy 85-90% in experienced cytologist's hands)
• CT/MRI helpful for treatment planning to determine disease extent and whether facial nerve would need to be sacrificed during surgery

Differential Diagnosis

• Can be limited by patient's demographic information: age and immune status
• Facial nerve palsy implies malignancy and poor prognosis
• Children: hemangioma, lymphangioma, first branchial cleft cyst, pleomorphic adenoma
• AIDS: benign lymphoepithelial cysts, infection, lymphoma
• Adults: pleomorphic adenoma (>80%), Warthin tumor, malignant tumor (mucoepidermoid, adenoid cystic carcinoma), metastasis, lymphoma
• Other nonneoplastic parotid masses: reactive adenopathy, cystic lymphoid hyperplasia, sarcoidosis

Our case: Warthin tumor confirmed by biopsy

References:

1. Steward M, Selesnick SH. Differential Diagnosis in Otolaryngology: Head and Neck Surgery

2. Castillo M. Neuroradiology Companion: methods, guidelines, and imaging fundamentals, 3rd ed, 2006