Anything new for brown spots on dorsal hands and face?

IPL. They turn black and fall off. Works great. (Intense Pulsed Light)

Acanthosis nigricans. Supposed to be due to hyperinsulinemia - which is due to insulin resistance. I have seen very few patients get rid of them by improving their insulin sensitivity

Brown spots do not have the same etiology or histology. Sometimes IPL, laser (Q-switched 532nm, 694 nm), fractionated resurfacing, hydroquinones, sometimes a mix, sometimes nothing works. Avoiding further sun exposure is pretty much (almost always) an element in the reduction and elimination of brown spots.

I have a question. I recently noticed some kind of a mole under my tongue. Should anything be done about it? It's approximately 3mm.

I've heard some doctors use liquid nitrogen to freeze and kill brown spots. Maybe that can help Ella? What is the name of that procedure?

RESPONSE TO LANDO:
Acanthosis Nigricans is a totally different thing and has nothing to do with the lentigenes on the dorsum of hands.