The purpose of this study is to evaluate the use of a device in the detection of tumor tissue versus normal tissue at the time of surgery. The technique used by the device is called laser-induced fluorescence spectroscopy (LIFS). The LIFS device (a laser) will generate a fluorescence (very low-intensity light beam) that will be focused on the diseased and/or normal tissue, and measurements of the light will be taken using a probe. If successful, researchers hope that LIFS could be used to help surgeons more clearly differentiate tumor tissue from normal tissue to improve surgical outcomes. Participants in this study are patients who will be having routine surgery for a brain, breast, head, neck, or skin tumor; temporal lobectomy for epilepsy; or amputation due to a tissue condition such as tumor, infection, lost circulation, or necrosis. The use of LIFS in the detection of tumors is experimental.