Hypertrophic First Rib
Rib hypertrophy, often at the costochondral junction and particularly involving the first rib, commonly mimics a lung nodule on the PA projection. It has been called “the medical student’s tumor.” Clues that the “nodule” is in fact due to rib hypertrophy include its absence on the lateral view, bilaterality, and the presence of rib hypertrophy at other levels. If there is any doubt, a lordotic projection can be obtained.