A 72-year-old woman presented for her annual physical examination. She had been treated for tuberculosis 20 years earlier. The patient did not smoke cigarettes; she denied fever, chills, and rigors. Drs Sonia Arunabh and K. Rauhilla of Flushing, NY, report that the clinical examination was unremarkable. Results of a purified protein derivative test were negative. Bilateral hilar lymph node calcification was found on an x-ray film (not shown) and a CT scan (A, arrows) of the chest. The stable, calcified lymph nodes were evident on a CT scan of the chest obtained 10 years earlier; this finding and the negative results of the evaluation suggested that this condition represented a healed tubercular lymph node infection. Hilar lymph node calcification usually results from healed granulomatous infections, such as tuberculosis and histoplasmosis, and sarcoidosis. Most affected patients are asymptomatic. However, in some patients, these nodes may erode into the contiguous airway and cause broncholithiasis and subsequent hemoptysis. Other mediastinal structures that may calcify include the pulmonary arteries and the aortic arch as seen on the chest CT scan of a different patient who had long-standing hypertension (B, arrow). Calcification of the aorta is noted in many elderly patients and has no clinical significance. Calcification of the pulmonary arteries may occur in patients with pulmonary artery hypertension.