Metastatic hypernephroma to the head and neck.

Eight cases of metastatic hypernephroma to the head and neck are presented with CT documentation. Hypernephroma is the third most common infraclavicular tumor to metastasize to the head and neck. Such metastases occur in about 15% of patients with this neoplasm, and nearly 8% of patients with this tumor present with disease in the head and neck region. These metastases are usually vascular and may either clinically precede the diagnosis of the renal primary tumor or may occur many years after apparently successful surgery of the primary tumor. These unusual patterns of behavior are reviewed. One of the cases presented here is the first reported incidence of cervical lymph node metastasis with hemorrhage to be documented by CT, thus adding this entity to the list of imaging differential diagnoses of cystic-appearing neck masses.