Cause of spread of PTC through lymphatics- The development of *intratumoral lymphatics* in well-differentiated papillary thyroid carcinoma appears to be associated with the spread of tumor to regional lymph nodes. The mechanisms underlying PTC with local invasion, LN metastases and distant metastases are not well investigated.Though it is seen that 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.