Hemopneumothorax is not a common condition. The majority of cases follow trauma, either in military or in civil life, but the spontaneous form is distinctly rare. After a scrutiny of the literature for the last thirty-four years I have been able to find only thirteen recorded cases.
Ten of these reported cases deserve to be called spontaneous for lack of any definite cause, such as demonstrable disease or trauma. The remaining three were due to tuberculosis and one of them was complicated by artificial pneumothorax. Among the ten spontaneous cases three were fatal and seven patients recovered; of the three tuberculous patients, two recovered and the one with artificial pneumothorax died. These thirteen cases are all true cases of hemopneumothorax and not just hemothorax or pneumothorax. The term hemopneumothorax should be applied to cases of lung collapse with undoubted blood and air within the pleural cavity and not just blood-stained
FREY JL. A CASE OF SPONTANEOUS HEMOPNEUMOTHORAX. JAMA. 1935;104(16):1395-1399. doi:10.1001/jama.1935.02760160019006