There is a solitary, large, exophytic, bone lesion arising from the right second rib, posterolateral aspect. It has medullary and cortical (outer and inner cortex) continuation with the rib. It measures 7.5 x 6.6 x 6.4 cm (anteroposterior x transverse x craniocaudal).There is remodelling of the rib. The lesion appears expansile with a thin peripheral cortex. It has lucent areas centrally, with multiple osseous septations and an irregular, nodular margin secondary to multiple sessile components. There is no associated abnormal soft tissue mass, no periosteal reaction and no cortical disruption or pathological fracture. Regional mass effect is present due to its expansive nature, with attenuation and bowing of the third and fourth ribs. There is no abnormal lesional or soft tissue enhancement.
The right subclavian artery is displaced mildly anteriorly by the large expansile osseous mass arising from the second rib. The right subclavian, axillary and brachial arteries are otherwise patent and normal.
The scapula, clavicle and rest of the ribs are intact and normal with no other similar bone lesion present.