45 year-old male complains of pleuritic chest pain following a "long" flight. What's the diagnosis and what's this sign called?

First described by Dr. Aubrey Hampton in 1940, hampton hump is a peripheral (pleural) based opacification found on chest X-ray; it occurs secondary to infarction of the lung

Although commonly associated pulmonary embolism it may occur secondary to other causes of lung infarction

Here are some other infrequent, but not rare signs, of pulmonary embolism on chest X-ray: