Lump above ankle where calf muscle begins been there a year. soft and painless. doctor said it was just hypertrophy of muscle? could it be cancer?

Possible, not likely: You don't indicate how long the lump has been present or how well defined it is. Can you feel its margins distinctly or is it vaguely defined. In any event, a soft tissue ultrasound or MRI of the area would exclude significant abnormality in this area. It appears to bother you so ask your doctor.

Watch, monitor it: You should look for any increase in its size. Unless it grows in size, it is not cancer. So measure its size carefully once every month and you will know in 6-12 months if it growing and needs further testing with x-rays and scans.