Regional recurrence of thyroid cancer means the cancer has spread to the regional lymph nodes in the neck. The drawing shows the surgical regions of the neck. As we’ve discussed on previous pages, recurrence in level 6 is considered local recurrence. Regional recurrence occurs in level 2 through 5. Disease in level 1 is very rare and for purposes of our discussion we can ignore it.
Cancer in region 2 through 5 is also known as lateral neck recurrence. It occurs in less than 10% of patients with thyroid cancer, but it is a unique clinical entity and it is generally treated surgically. Patients with larger tumors and more aggressive features on microscopic inspection are at higher risk. The most important predictor of lateral neck disease is lymph node involvement in level 6. The greater the number of involved lymph nodes in level 6, the greater the chances of disease in the lymph nodes of the lateral neck. More than 5 positive lymph nodes in level 6 is highly predictive of lateral neck disease.
As with other types of recurrence, regional disease may become apparent within months or years after the initial diagnosis. It is usually diagnosed when an elevated thyroglobulin level is found and ultrasound identifies metastatic disease in the regional lymph nodes in the lateral neck. The diagnosis is made by ultrasound guided FNA. Usually a total body iodine scan is performed to exclude patients with distant metastasis. If regional disease is the only focus of metastatic cancer, surgery is usually recommended. Simple removal of the grossly apparent cancerous nodules (“berry picking”) is not recommended as the risk of persistent disease is high. The best approach is a modified radical neck dissection. This is a systematic removal of the lymph nodes in level 2 through 5. It offers the best chance of rendering the patient disease free.