A 27-yeаr-оld wоmаn cоmes to the clinic reporting а painless lump near the opening of her vagina that she noticed two days ago. She denies fever or significant discomfort but says the lump feels “like a small marble” when she sits. On exam, you observe a soft, non-tender mass at the 4 o’clock position of the vaginal introitus. Based on the information provided, this finding is likely which of the following?