A case of pulmonary silicosis associated with triple lung cancers is p
resented. Two of the three tumors were unexpected clinically. The disc
ussion deals with the diagnostic difficulty in radiological differenti
ation between the pneumoconiotic mass lesion and superimposed tumor sh
adows, as well as the possible causal relationship between the two con
ditions. From the practical point of view, elderly patients with pneum
oconiosis should be carefully monitored for the development of lung ca
ncer.