Misplaced parotid glands: bilateral agenesis of parotid glands associated with bilateral accessory parotid tissue.

Agenesis of the parotid is a rare entity. It is usually unilateral but bilateral cases have been described as a rare cause of xerostomia. Accessory parotid tissue is also uncommon and is not normally associated with aplasia of the parotid gland. The embryological, histological, clinical and radiological findings of these two entities will be discussed in addition to the report of an obscure case of bilateral parotid agenesis together with bilateral accessory parotid tissue.