A simulated tissue model, comprising: a first layer made of silicone having a substantially planar first surface opposite a substantially planar second surface defining a first thickness therebetween; the first layer having an outer perimeter and a protrusion extending outwardly from the first surface at a protrusion location within the outer perimeter; the first thickness being substantially uniform and the protrusion being defined by an increased first thickness of the first layer; and a second layer made of silicone having a substantially planar first surface opposite a substantially planar second surface defining a second thickness therebetween; the second thickness being substantially uniform; the second layer having an outer perimeter and being connected to the first layer such that the outer perimeter of the first layer and the outer perimeter of the second layer are aligned and the first surface of the second layer faces and contacts the second surface of the first layer; characterized in that the simulated tissue model further comprises a release layer between the second surface of the first layer and the first surface of the second layer, in an area on the second surface of the first layer opposite to the protrusion on the first surface of the first layer, wherein the first layer and the second layer are adhered together with adhesive and the release layer prevents adhesion of the second surface of the first layer to the first surface of the second layer in the area of the second surface of the first layer that is opposite to the protrusion on the first surface of the first layer, such that the first layer and second layer are separable in the area of the second surface of the first layer that is opposite to the protrusion, to permit the protrusion to be excised from the tissue model by making an incision through the first layer extending around the protrusion. a first layer made of silicone having a substantially planar first surface opposite a substantially planar second surface defining a first thickness therebetween; the first layer having an outer perimeter and a protrusion extending outwardly from the first surface at a protrusion location within the outer perimeter; the first thickness being substantially uniform and the protrusion being defined by an increased first thickness of the first layer; and a second layer made of silicone having a substantially planar first surface opposite a substantially planar second surface defining a second thickness therebetween; the second thickness being substantially uniform; the second layer having an outer perimeter and being connected to the first layer such that the outer perimeter of the first layer and the outer perimeter of the second layer are aligned and the first surface of the second layer faces and contacts the second surface of the first layer; characterized in that the simulated tissue model further comprises a release layer between the second surface of the first layer and the first surface of the second layer, in an area on the second surface of the first layer opposite to the protrusion on the first surface of the first layer, wherein the first layer and the second layer are adhered together with adhesive and the release layer prevents adhesion of the second surface of the first layer to the first surface of the second layer in the area of the second surface of the first layer that is opposite to the protrusion on the first surface of the first layer, such that the first layer and second layer are separable in the area of the second surface of the first layer that is opposite to the protrusion, to permit the protrusion to be excised from the tissue model by making an incision through the first layer extending around the protrusion.