<s>[INST] i have a lump in my vagina lip that hurts when i squeeze it. It appears then disappears but then the process begins again in 3 months and will appear. It is about the size of a nickle, and sometimes turns into the size of a quarter. What is this? What causes it? I am 17 and it is truly scary. [/INST] Hi.This can be due to sebaceous cyst or cyst of any sort. The best treatment is get this checked and removed by a Surgeon.This will get you rid of the problem before it goes into complication and you get a histological diagnosis. </s>