Woud you please discuss the characteristics of cancerous lumps?

Here are some: Cancerous lumps are usually painless untill they get quite large and start growing into skin or deeper strutures. The lumps are usually hard and do not have any signs of inflammation around them. They typicaly keepl growing in size steadily getting bigger by the month.

Not easy to say: Tumors, be it benign or malignant, are often painless so i'm not sure you can tell without a biopsy. If a lump grows very fast or develops smaller nodules around it, i guess that would be suspicious of a malignancy but even so you can't tell for sure without tissue. If you have any suspicious lesion, especially if it popped up recently, have your doc take a look at it.