What is left apical probable 0.6 cm confluent osseous marking versus nodule overlying the junction of medial mid first rib and prozimal inferior clavicle?

There is a poorly defined osseous marking which appears confluent with the medial aspect of the proximal left first rib adjacent to the left clavicle. This area measures approximately 0.6 cm in size and is suspicious for a small nodule. Additional imaging is recommended.