We prove the first mathematical existence result for a model of dendri
tic crystal growth with thermal fluctuations. The incorporation of noi
se is widely believed to be important in solidification processes. Our
result produces an evolving crystal shape and a temperature field sat
isfying the Gibbs-Thomson condition at the crystal interface and a hea
t equation with a driving force in the form of a spatially correlated
white noise. We work in the regime of infinite mobility, using a sharp
interface model with a smooth and elliptic anisotropic surface energy
. Our approach permits the crystal to undergo topological changes. A t
ime discretization scheme is used to approximate the evolution. We com
bine techniques from geometric measure theory and stochastic calculus
to handle the singular geometries and take advantage of the cancellati
on properties of the white noise.