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MALDI IMS datasets comprise huge amounts of spectra and their interpretation requires the use of multivariate statistical methods. MALDI IMS spectral data have been processed using sequential principal component analysis and 2-D peak distribution tests so as to investigate the molecular differentiation of tumor regions in formalin-fixed paraffin-embedded tissue biopsies of colorectal adenocarcinoma. In some of the cases fresh frozen tissue section samples were also analyzed for comparison. Multivariate analysis of spectral data revealed a specific pattern of mass ion peaks in different tumor regions that were distinguishable from the adjacent normal regions within a given specimen. Moreover, similar mass ion peaks could be detected in both FFPE and fresh-frozen tissue section samples. These significant mass ion peaks have been used to generate ion images and visualize the difference between tumor and normal regions. These specific and statistically significant ion peaks may serve as potential biomarkers for colorectal adenocarcinoma.