Pulmonary sarcoma in a Rhesus monkey after inhalation of plutonium dioxide

A pulmonary fibrosarcoma of bronchial origin was discovered in a Rhesus monkey that died of pulmonary fibrosis nine years after inhalation of plutonium-239 dioxide. The tumor was well delineated but not encapsulated. It grew around the major bronchus of the right cardiac lung lobe and extended into the bronchial lumen and into surrounding pulmonary parenchyma. It also readily invaded muscular arteries, resulting in infarction and scarring in the right cardiac lobe. Despite this aggressive growth, the tumor did not metastasize. The primary cause of death was severe pulmonary fibrosis involving the alveolar septa and perivascular and peribronchial interstitium. Bullous or pericitrical emphysema was prominent. The initial lung burden of plutonium in this monkey was 270 nCi. This burden is equivalent to approx. 500 times the maximum permissible lung burden for man. The time-dose relationship for survival is consistent with that of dogs and baboons that inhaled plutonium dioxide, thus further strengthening the extrapolation of plutonium toxicity data from one species to another. 4 references, 3 figures, 1 table