Update: All spots have pretty much healed... at a very slow rate, and at this point to my dismay, they are leaving dark pigmentation BUT they did not grow, they shrank, SO they are not cutaneous mets :-)

It was probably stress-related cystic acne, which worried me because I've never had an adult breakout like that, and I'll have to be patient for the hyperpigmentation to go away if it does at all.
Interestingly, I've noticed any skin healing since receiving Cisplatin has resulted in darker pigmentation, like my old stomach tube exit.