What Causes Pea Sized Lump Near Clitoris?

my girlfriend has a a pea sized lump to the right of her clitoris. i cant find anything online about it, the only thing that pops is the bartholin gland & i know thats not it. she went to the doctors & her doctor said its a a swollen gland of some sort. do you guys know what it is? if so how is caused/treated?