In older adults, 80% of firm, persistent, and enlarging neck masses are metastatic in origin. The majority of these arise from squamous cell carcinoma of the upper aerodigestive tract, such as nasopharynx, tonsils, tongue base, and larynx. A complete head and neck examination may reveal the cancer of origin, but often imaging and examination under anesthesia are necessary to detect the primary lesion. Detecting the primary lesion is essential since it may directly impact oncologic treatment modalities. Initial radiologic screening exams typically include a CT, MRI, or PET. After imaging, many patients require direct laryngoscopy, esophagoscopy, and tracheobronchoscopy to further elucidate the primary lesion. At this time, biopsies may be taken for suspicious lesions. Fine-needle aspiration of neck masses are also routine and may help determine the diagnosis while evaluation of the primary malignancy is ongoing. Open neck biopsy should only be performed by head and neck surgeons experienced in the management of head and neck cancer since complications from open biopsy may make subsequent formal neck dissections more challenging if cancer is detected. With the exception of papillary thyroid carcinoma, non–squamous cell metastases to the neck are infrequent. While cancers that are not primary in the head or neck seldom metastasize to the cervical lymph nodes, the supraclavicular lymph nodes are quite often involved by lung, gastroesophageal, and breast cancers. Infradiaphragmatic cancers, with the exception of renal cell carcinoma and testicular cancer, rarely metastasize to the neck.
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