Enlarged neck lymph nodes containing squamous cell cancer may be the first sign of cancer elsewhere in the body. Since this type of cancer always begins elsewhere and never begins in these nodes, a search is made for the primary site. If a cancer has previously been diagnosed elsewhere, it naturally is the likely source, especially if the pattern under the microscope is similar.
Sometimes the biopsy of the lymph nodes will show adenocarcinoma or lymphoma. In these cases the primary site is less likely to be in the head and neck. For enlarged nodes containing squamous carcinoma in the lower half of the neck, the primary site may be the head and neck but may also be in the esophagus, lung or genitourinary tract.
Most epidermoid carcinomas found in lymph nodes in the upper half of the neck are a result of spread from primary head and neck cancers.
Evaluation A very careful history and physical examination is necessary to try to find the primary tumor. This frequently turns up cancer in the nasopharynx, oropharynx or larynx. If a cancer originating in the head and neck is found, other organs such as the lungs, liver and bones should be evaluated. If the cancer has already spread to one of these sites, then the treatment plan is directed towards metastatic disease and not to cure of the primary lesion (which would involve very aggressive local therapy).
Repeated examinations will sometimes find the primary tumor still at a treatable stage. A vital part of the solution to the puzzle is provided by pathologic examination of the biopsy specimen.
