School ager with cystic fibrosis and a right chest wall mass

CXR of osteomyelitis of the rib
CXR PA and magnified view of the ribs (below) shows dense opacity in the right upper lobe and marked periosteal reaction of the right 4th rib posteriorly.

The diagnosis was botryomycosis (recurrent staphylococcus infection) resulting in osteomyelitis of the rib in a patient with cystic fibrosis.