Breast tumor detection with microwaves is based on the difference in dielectric properties between normal and malignant tissues. The complex permittivity reconstruction of inhomogeneous dielectric biological tissues from microwave scattering is a nonlinear, ill-posed inverse problem. We proposed to use the Huber regularization in our previous work where some preliminary results for piecewise constant objects were shown. In this paper, we employ the Huber function as regularization in the even more challenging 3D piecewise continuous case of a realistic numerical breast phantom. The resulting reconstructions of complex permittivity profiles indicate potential for biomedical imaging.