Hard lump on right leg

I am a 50 year old woman, I found a large lump that popped up suddenly on my right leg, just above and to the right of my knee.  It is not painful.  It is not soft like a lipoma.   I am scheduled for an MRI but not a biopsy.  According to all of the information that I have read about this, it is likely a malignancy.    It is currently the size of a cherry tomato and when I am in a squatting position where the muscle is engaged, it protrudes.   Why did I get scheduled for an MRI and not a biopsy if it is most likely a cancer?   What else could it be if not cancer or lipoma?

[iam1butterfly]

I seriously doubt that it's Cancer... maybe, it's some sort of calcification
or cyst (benign nodule).
Anyway, the MRI will scan and give a visual image of the lump and underlying
tissue. A biopsy is only performed when there is a growth of a suspicious nature.
I really wouldn't be thinking about Cancer if I were you.
By the way, there are no lymph nodes in the knee; so, it's not likely Lymphoma.

[jonko77]

how did your lump turn out ?