PTEN and metastatic neoplasm: Our group has recently reported on two breast AdCCs with high-grade transformation; our findings confirmed that progression occurred via the acquisition of additional genetic events and/or clonal selection; however, none of the genetic alterations reported in the progression of salivary gland AdCCs were found in breast AdCCs.7 In a distinct study of a single breast AdCC metastasizing to the kidney,92PIK3CA and PTEN mutations were found in both the primary and metastatic tumors, but, the metastatic deposits showed increased PTEN promoter methylation and lower PTEN gene expression levels.