Endoscopic systems including multimode optical fibers for and methods of interrogating a portion of a body are described. In an example, the endoscopic system includes a multimode optical fiber, a coherent light source positioned to emit coherent light through the multimode optical fiber, and a photodetector positioned to absorb scattered coherent light emitted from the multimode optical fiber and configured to generate a speckled light signal based on the scattered coherent light. In an example, the endoscopic system includes a controller configured to analyze the speckled light signal with machine learning classifier and to generate an identification signal indicative of a characteristic of the portion of the body.