1. you did just use that word in a sentence
2. if a doctor would use the word tumor in a sentence they would probably say "we need to remove the tumor from this persons body."
The tumor is malignant.
The surgeon carefully excised the tumor from the left side of the man's head.
The tests show that the tumor is malignant.
Many people have brain tumors.
He dabbled in the occult. she had an occult tumor.
The tumor was benign; it was not harmful for now.
The oncologist informed her patient that the tumor was malignant.
The cancer had caused the cells to form a tumor; whether it was malignant or benign was unknown.
A tumor was removed from Billy's lung, but thankfully it was benign.