1. A medical image processing apparatus comprising: an edge extracting section that extracts, on the basis of a two-dimensional image of an image of a living tissue in a body cavity inputted from a medical image pickup apparatus, edges of the two-dimensional image; a three-dimensional-model estimating section that estimates a three-dimensional model of the living tissue on the basis of the two-dimensional image; a voxel extracting section that extracts, on the basis of positions of respective voxels, where the edges are present, estimated as a part of the three-dimensional model, a predetermined voxel group to be set as a calculation object of a shape feature value; a shape-feature-value calculating section that calculates the shape feature value for at least a part of voxels among the predetermined voxel group extracted by the voxel extracting section; and a tuberal-shape detecting section that extracts, on the basis of the shape feature value, a voxel group, a three-dimensional model of which is estimated as a predetermined shape, among at least the part of voxels and detects the voxel group as a voxel group forming a tuberal shape in the three-dimensional model of the living tissue.