The scalar auxiliary variable (SAV) approach presents a novel way to discretize a large class of dissipative systems. We consider a general Cahn-Hilliard system with mass source that may not admit a known dissipative structure, and so the stability of discrete solutions is not immediate. With a bounded mass source, we can show stability and convergence of time discrete solutions for a first order SAV scheme. We present some qualitative simulations for some Cahn-Hilliard systems with mass source that appear in tumor growth, image inpainting and image segmentation.