Fourier transform infrared fiberoptic evanescent wave (FTIR-FEW) spectroscopy has been suggested as a powerful tool for clinical diagnostics of normal, precancerous, and cancerous breast tissue ex vivo and in vitro in the middle infrared (IR) region of the spectrum (850-1850 cm(-1)). This method is suitable for noninvasive and direc, measurements of the spectra of normal and pathological tissues in vitro, ex vivo and in vivo. For the first time this method has been used nondestructively, rapidly, fast (15-20 sec) and remotely in the operating rooms of clinics. The aim of our studies has been the express testing of various tumor tissues during surgery to optimize and localize an area of removing tissue. We measured very small samples (about 1 mm in diameter) of normal and malignant breast tissue ex vivo with a fiber bent to a special angle, forming a special tip probe configuration. We also suggest here the minimally invasive FTIR-FEW diagnosis tool using "needle" changeable tip probe for biopsy applications. The spectral histopathology branching could be developed with help of this technique in vitro. The breast tissue at different stages of tumor or cancer has been distinguished very clearly in spectra of amide, cyclic and noncyclic hydrogen bonded fragments, phosphate groups and sugars.