Genomic diagnostics in cancer has evolved since the completion of the Human Genome Project and the advancements made in diagnosis and therapy in chronic myelogenous leukemia. Among the diseases to achieve limited success or potentially benefit from diagnostic genetic testing are thyroid cancer, Burkitt's lymphoma, gastrointestinal stromal tumors, adrenocortical carcinoma, and colorectal cancer. With increased understanding of genomics, genetic tests should improve diagnosis and help guide medical and surgical management. J. Surg. Oncol. 2015 111:24–30. © 2014 Wiley Periodicals, Inc.