Cancer of the vulva grows primarily by invasion of surrounding tissue.
Tumor cells can invade blood and lymph vessels leading to metastases, primarily to regional lymph nodes. Tumors < 2 cm localized laterally on the vulva (at least 1 cm from the midline) will drain lymph to lymph nodes in the groin of the same side. With larger tumors and tumors in the midline, spread can occur to lymph nodes on both sides. Further spread can occur to the external and internal iliac lymph nodes, and further up to the common iliac vessels and and paraaortic lymph nodes.
The frequency of metastatic spread to lymph nodes increases with increasing tumor volume and advanced stages.
In the case of invasion of blood vessels, tumor cells can spread to the lungs causing lung metastases.