The present invention relates to an optical scanning probe assembly for microscopic guide optic scanning and inspection of tissues suitable for application in, e.g. in vivo medical inspection and biopsy. The assembly comprises an outer housing (3) comprising: i) a spring element for a scanning motor, the spring element formed as a hollow tube (5) adapted to receive an optical guide, the hollow tube having mechanical stiffness larger than the optical guide to be received, ii) a lens system (7) and iii) N means for deflecting (6) the distal end of the hollow tube in directions transverse to the longitudinal extension of the hollow tube, so as to form an optical scan pattern. The optical assembly is particularly advantageous as it increases the freedom to optimize the optical and mechanical performance of the system which is defined respectively by the optical guide and by the hollow tube. The probe can be used in resonant and non-resonant scanning modes.