[False mass of the thoracic wall in obese adolescent girls].

Each of four obese adolescent females were thought to have pre-sternal anterior chest wall "masses" when evaluated by lateral chest radiograph. All had normal physical examinations. The apparent chest wall masses were found to be an artifact created by partial midline contact of both, large breasts, surrounded by a partial midline air space adding contrast to the adjacent soft tissue. Manual abduction of the breasts was followed by disappearance of the apparent radiographic abnormality.