[High-resolution sonography after surgery of cystadenoma lymphomatosum of the parotid gland].

Clinical and sonographic examinations were carried out on 38 patients who had undergone excision of a parotid gland for adenolymphomas and the results were compared. In 23 of these patients (60%) sonography showed further tumours on the same or opposite side, or bilaterally. The incidence of multiple tumours is therefore significantly higher than has been assumed so far. In 76% of patients, sonography showed clinically occult cystadenoma lymphomatosum. Only 14% of tumours smaller than 12 mm were detected clinically. In four patients, tumours larger than 12 mm, but lying deep in the gland were missed on palpation. In view of the frequency of multi-local or bilateral tumours, sonography of both parotids should be performed if there is clinical suspicion of a parotid tumour.