Background: Synchronous unilateral tumors of the parotid gland are found only rarely. The majority of these are multifocal Warthin's tumors (papillary cystadema lymphomatosum). The incidence is reported to range up to 12%. Malignant processes develop within a pleomorphic adenoma in about 6.6% of all cases. In a few cases, they also develop in a Warthin's tumor. Two coexisting benign parotid tumors of different histologic types are extremely rare.
Patients: In this report we present a patient with an unilateral pleomorphic adenoma and a Warthin's tumor. It is the eleventh published case of this kind. The problems of diagnosis, differential diagnosis, and surgical therapy of benign multiple parotid tumors are discussed. The current literature is reviewed.
Results: Synchronous multiple Warthin's Tumors or multiple tumors of different histologic types in the same parotid gland are found rarely. Nevertheless careful preoperative diagnosis causing B-mode ultrasound as the primary imaging modality. Meticulous intraoperative inspection and palpation of the glandular tissue and periglandular lymph nodes is indicated. In order to ensure adequate tumor removal, the therapy of choice is a total or subtotal parotidectomy.
Conclusion: We suggest careful preoperative diagnosis and meticolous intra-operative exploration in order to localize multifocal lesions of benign parotid tumors. This minimizes the chance of overlooking synchronous tumor foci, which would necessitate difficult revision surgery entailing a risk of injury to the facial nerve.