The invention relates to a tissue morcellator for minimally invasive surgery. The morcellator has a metallic cutting ring mounted on a visually transparent hollow cylinder, which in combination with a visually transparent outer morcellator tube enables a surgeon to visualize the inside of the morcellator shaft for detection of loose tissue fragments in the device. A tenaculum used with the morcellation device has a spacer for preventing contact with the blade. The cutting tube can oscillate, rather than rotate, along the longitudinal axis of the cutting tube. The morcellator utilizes an extendable tissue guide on the outer tube of the morcellator shaft for preventing the tissue from rotating along the longitudinal axis of the morcellator tube. This allows the tissue to be continuously rotated into the morcellator device for continuous peel. The tissue guide can also be fully retracted to allow for coring of the bulk tissue.