Papillary thyroid carcinoma with lymph node metastases.

Papillary thyroid cancer (PTC) is the most frequently occurring human thyroid cancer with good prognosis following appropriate treatment. Lymph node (LN) metastases are the main way through which PTC spread cancer cells. The mechanisms underlying PTC with local invasion, LN metastases and distant metastases are not well investigated. Tumor secrete cytokines, such as vascular endothelial growth factor (VEGF)-C and -D bind to VEGF receptors on lymphatic endothelial cells and induce proliferation (budding) from nearby lymphatic capillaries and growth of new lymphatic capillaries. About one-third of patients can be diagnosed at the time of surgical findings. Different image studies, such as ultrasonography with fine needle aspiration cytology, scintigraphic localization and positron emission tomography were reported to detect LN metastases. Important factors in predicting LN metastases are vascular invasion, male gender, absence of tumor capsule, and perithyroid involvement. Tumor recurrence in LN after primary treatment of PTC had an independent and highly significant negative effect on survival in patients over 45 year-old. Recombinant adeno-associated virus-mediated gene transfer of sVEGFR3-Fc is a feasible therapeutic scheme for blocking lymphogenous metastasis. In conclusion, aggressive surgical procedures performed by experienced surgeons or postoperative radioactive iodine therapy to minimize local recurrence of LN for PTC patients with high risk.