If I only have some excess fat and skin by my armpits, is a medial arm lift with a disguised scar possible? (Photo)

Based on your inquiry and photos, it seems you're concerned about excess fat and skin in the armpit area. While a full assessment requires an in-person consultation:
VASER Arm Liposuction: This might be preferable for you. It liquefies fat and stimulates skin contraction, offering minimal scarring and a contoured appearance.
Medial Arm Lift: This could lead to potential issues like armpit webbing or 'dog ears'.
Given this, VASER liposuction might be more fitting. However, consult a board-certified plastic surgeon for the best guidance.
Sincerely,
Dr. Katzen

You can undergo a transverse incision in your axilla with liposuction of the remaining part of the arm. This can tighten up and be less costly.

Best Wishes,

Gary Horndeski, M.D.

You will be candidate for deep tissue liposuction to the 360 circumferential arms.
You have saggy skin on your arms which will not improve doing any incision in the armpit fold because it is not about excess of length, it is always excess of width. So I consider just liposuction using some energy to tighten the skin.
Be encouraged!
Dr. Cárdenas