The present invention provides an endoscope for in vivo imaging the cells, tissue, organs or body cavities of humans or other animals to observe and locate, diagnosis and / or treat disease. Illumination sources, image detectors, sensors may be provided alone or in combination on the removable tip allowing functional alterations or optimization for a particular procedure. Endoscope features such as an instrument channel supporting tissue sampling, suction, treatment, micro-surgery, optical computed tomography, confocal microscopy, laser or drug treatments, injections, gene-therapy, marking, implanting or other medical techniques are maintained.