2cm nodule on my shin for over 5 years.more prominent when i contract my leg, but these lasts months i feel a little of tenderness. can it be cancer?

Nodules and growths: It is a good thing to keep an eye on nodules and growths because sometimes they could be cancer, often they are benign. Sometimes benign growths can turn into cancer. Sometimes they are infectious. We can get a lot of information by examining a growth, but a biopsy (a piece of tissue examined in the lab) is the gold standard for telling you the nature of a growth. The short answer is get it seen.