When it comes to treating cancer, surgeons want to get rid of as much cancerous tissue as possible during tumor removal. Now a new technology - the size of a pen - is attempting to make that easier by distinguishing between tumors and healthy tissue in just 10 seconds. The MasSpec Pen is a real-time diagnostic tool created by researchers at the University of Texas at Austin. In a new study published Wednesday in the journal Science Translational Medicine, the researchers report that their handheld device (which is not yet FDA-approved) uses tiny droplets of water to analyze human tissue samples for cancer. "It's a gentle, simple chemical process," says study author Livia Schiavinato Eberlin. "It's highly specific and highly sensitive. The fact that it's non-destructive brings a new approach to cancer diagnosis." Getting rid of all cancerous tissue while also preventing any harm to healthy tissue is a delicate process. Other tools available to surgeons for tissue diagnosis ... use gases or solvents that can be harmful for the human body [and] are slower than the MasSpec Pen. In the study, the researchers tested 253 human tissue samples from lung, ovary, thyroid and breast cancer tumors and compared them to samples of healthy tissues. The device was 96% accurate at identifying cancerous tissues. The researchers also tested the MasSpec Pen in live mice with tumors and found that the device was able to identify the presence of cancer without harming healthy surrounding tissues.