Systems, methods, and dressing are presented for treating a tunnel wound on a patient. In one instance, a reduced-pressure, tunnel-wound dressing includes a longitudinal core member formed from a closed-cell foam that is surrounded by a first longitudinal concentric member formed from a manifolding material. When subjected to reduced pressure, the longitudinal core member expands and the first longitudinal concentric member compresses. These actions create intimate contact between the tunnel wound and the dressing, oppose collapse of the tunnel, and when reduced pressure is removed provide clearance to remove the dressing. Other embodiments are presented.