The importance of heterogeneity in tumor pathology

Heterogeneity of cell, tissue, and tumor genotype, form, and function confounds clinicopathologic research and therapeutic strategies. Its significance and importance usually are underestimated and underreported, and there is no consistent statistical or biomathematical framework for its interpretation. New technologies for the quantitative study of pathology specimens and a growing awareness of the clinical importance of biodiversity within individual tumors and populations of tumors herald new approaches to the problems posed by dynamic structural and functional complexity in human tumors.