Male, 31years, diagnosed w/ 0.7cm kidney parenchima mass, little fat in ct. if malig, what are the chances of it already spread?

Probably Low: Only 50% of masses with a diameter smaller than 1 cm are malignant. Despite the localized, nonaggressive behavior of most small renal tumors, up to 5% of patients with masses 4 cm or smaller present with metastatic disease so we would expect the risk for your 7 mm mass to be much lower. Don't ignore it, get treated, good luck. Check out: http://gucasym.Org/dilemma-small-renal-mass.