I would recommend treating the age spot with Melarase PM followed by IPL or fractional laser to eliminate the pigmentation.
I always recommend any lesion is assessed by a board certified dermatologist before deciding it is a cosmetic lesion. It is possible that rarely underneath a seborrheic keratosis there could be another lesion in which case your dermatologist should decide if it needs a biopsy.
Liquid nitrogen removes actinic and seborrheic keratoses well but if its a very thin or very thick lesion, the doctor may under treat in which case a second treatment may be needed. If the lesion is a lentigo, I find IPL a better treatment than freezing after one is sure that this lesion is benign.
I would recommend you return to your dermatologist and discuss what the best plan is for you depending on what type of lesion was being treated.
All the very best.
If something was treated with liquid nitrogen and it did not resolve, I would definitely recommend having the lesion rebooked at and possibly biopsied. The most important thing however is to go to a qualified board-certified dermatologist to get e proper treatment.
age spots need lasers, IPL, microneedling treatments for the best outcomes. Please see an expert to determine if these are aging spots and if they can be treated more appropriately. Best, Dr. Emer.