This name comes from the appearance of the cut surface of a solid malignant tumor , with `` the veins stretched on all sides as the animal the crab has its feet , whence it derives its name '' .
He used this term because he thought that if a solid malignant tumor was cut into , its veins looked like a crab : `` the veins stretched on all sides as the animal the crab has its feet , whence it derives ( gets ) its name '' .