What Causes Itchy And Sore Lump Under The Skin Of Vulva?

I have found a hard lump under the skin of my vulva. I is under the inner labia majora. It is invisible and irregular in shape. It becomes itchy and sore when i walk or sit for a long time. It doesnt really move. I am 18 years old and not sexually active. I am really worried - does it seem like it could be cancer??