A 19-year-old girl comes to the clinic due to a left wrist mass.  She noticed swelling on the top of her wrist about 4 months ago and came to the clinic due to cosmetic concerns.  Examination shows a nontender, rounded mass on the dorsal wrist that transilluminates with a penlight. Vital signs are normal. The patient needs to type on her computer almost all day. She is left-handed. She does not smoke or use illicit drugs. She is in sexual relationship with two male partners and uses condoms.