The growth or dissolution of a particle under compression or simple shear is investigated by means of an analytical approach. The changes in shape and size of the particle are determined by the combination of two interphase movements: migration (with respect to matter) and advection (driven by the moving matter). The problem is solved by an indirect original method, where the particle surface is derived as the envelope of a family of straight lines (2D) or planes (3D), which leads to closed form parametric equations. It is shown that the shapes of deformed particles are close to, and can be fitted by, ellipsoids. The equivalent strain dependence of the aspect ratio is similar for both investigated loading paths: particle flattening or elongation is reduced by growth, and conversely increased during dissolution. Finally, upon growth from a zero initial radius, the aspect ratio is a function of the applied strain only, which is contrary to intuition.