yes you should be concerned about cancer. Not that it is, but it dosen't sound good. Even if it's only benign (non-cancerous) the doctor may want to remove it as sometimes they can deveolp into cancer. Check it out with a dermatologist right away.
Hello,
Without examination it is very difficult to confirm a diagnosis,but it can be lentigene,solar keratosis(small rough or scaly areas of skin due to damage from sun exposure), seborrheis keratosis(small lumps due to a thickening of an area of the top skin layer), mole or a malignancy.
I sincerely advise you consult a dermatologist and get the diagnosis confirmed.
Hope it helps.Take care and pls do keep me posted on how you are doing or if you have any additional doubts.Kind regards.