Using a novel automated Mueller matrix polarimetric imaging system we acquired and generated the Mueller matrix images of normal, benign, and cancerous tissue from a Sinclair swine. A polar decomposition of these Mueller matrices yields the retardance, diattenuation, and depolarization parameters for each skin sample. The results, presented in this paper, from the retardance decomposition indicate the ability to use this parameter to discriminate between benign and cancerous lesions.