Unilateral, multicentric Warthin's tumor mimicking a tumor metastatic to a lymph node. A case report

BACKGROUND: Warthin's tumor may be associated with false positive diagnoses of malignancy on fine needle aspiration. The most common cause of error is markedly atypical squamous metaplasia mimicking metastatic cystic squamous carcinoma. The common location of Warthin's tumors within periparotid nodes may add to the clinical suspicion of metastasis. We report a case of unilateral, multicentric Warthin's tumor arising in periparotid and intraparotid glands, leading to a strong clinical and cytologic suspicion of malignancy. CASE: A 60-year-old female presented with a 3-month history of several enlarged lymph nodes in the right side of the neck. Fine needle aspiration, performed at the right upper neck lymph node, suggested the possibility of metastatic tumor. On computed tomography and ultrasonography there were 4 nodular lesions in the right retromandibular area and lateral aspect of the neck, 1-1.5 cm in diameter. A thyroid scan revealed diffuse enlargement of the thyroid gland and a nodular lesion in the right lobe. Right thyroid lobectomy and modified radical neck dissection, including right superficial parotidectomy, were performed for evaluation of occult malignancy. Histologically we confirmed that the tumor was a synchronous, multicentric Warthin's tumor arising in the parotid gland and intraparotid and paraparotid lymph nodes. CONCLUSION: Clinicians and pathologists should consider an extraparotid Warthin's tumor in the differential diagnosis of multiple cervical masses.