-year-old man presented with a 2-day history of worsening shortness of
breath associated with cough productive of clear, occasionally greenish
sputum. He reported an episode of mild hemoptysis. These symptoms were
preceded by left pleuritic chest pain for 1 week prior to hospital
admission. There was no history of fever, recent surgery, trauma, or
prolonged immobilization. He did not notice any leg swelling and had no
previous similar episodes of illness. He was a nonsmoker, and there was
no family history of thromboembolic disease.