Abstract: An on-spot abnormal tissue detection system includes a light source, a housing, a light fiber, a collimating lens, one or more beam combining mirrors, one or more focusing optic lenses, one or more achromatic doublet lenses, a spectrometer, a fiber optic cable, and a computing system. The computing system can receive wavelength intensity pairs for spot locations of the target area from the spectrometer, determine a standard deviation and variance measurement of the wavelength intensity pairs for the spot locations, determine whether tissue for the spot locations of the target area is a tissue type of a tumor or normal tissue based on the standard deviation and variance measurement of the wavelength intensity pairs, and send the determination of whether the tissue for the spot locations of the target area is a tissue type of a tumor or normal tissue to a display.