[Cystic neck lymph node metastases as an indication of occult tonsillar carcinoma].

BACKGROUND: Cystic carcinomas of the neck without evidence of a primary tumor are diagnostically challenging lesions. Differentiation between a cystic lymph node metastasis of an occult primary tumor and a carcinoma arising in a branchiogenic cyst is frequently not possible even with histological examination. In order to clarify the diagnosis, an intensive search for a primary lesion in the upper aerodigestive tract must be carried out.

DIAGNOSIS: An occult carcinoma might be situated in Waldeyer's ring, especially in the tonsillar crypts. These tumors tend to produce cystic metastases in the jugulodigastric region. Therefore, multiple biopsies have to be taken from the tissue of Waldeyer's ring. In the case of a positive histological result, adequate therapy of both the primary and the metastasis can be carried out. The diagnosis of a malignant branchiogenic cyst is only permissible after a primary lesion has been thoroughly excluded.