The implication of anthracosis in the development of pulmonary adenocarcinoma

The relationship between anthracosis, which is the deposition of black dust matter in the lung parenchyma, and the development of pulmonary adenocarcinoma has not been fully characterized. In order to clarify whether background black dust matter deposition could be implicated in the development of pulmonary adenocarcinoma, we measured the level of anthracosis at autopsy in 47 patients who had died of pulmonary adenocarcinoma. Both lungs of all 47 cadavers were examined. Twenty-micrometer sections were cut from formalin-fixed, paraffin-embedded blocks of the largest cut surface of each lung. Black dust matter was extracted from the sections and blotted onto a nitrocellulose membrane. The density of the blotted black dust matter was then analyzed using an imaging densitometer. There were no significant differences in the density of black dust matter deposition between lungs affected by pulmonary adenocarcinoma and control lungs. However, well differentiated adenocarcinomas tended to develop more frequently than poorly differentiated ones in lungs showing less deposition. We found a very strong correlation between the degree of black dust matter deposition and smoking history. Patients with severe anthracosis tended to have a poorer prognosis than those with mild anthracosis.