Lung cancer associated with punctate calcification: CT and histological correlation

The etiology of punctate calcifications in lung cancer was evaluated on the basis of CT and histological correlations. Seven cases of lung cancer with punctate calcifications were demonstrated on CT. The patients had undergone surgical resection (five men and two women, 60-70 years old; six adenocarcinomas and one squamous cell carcinoma), and each case was evaluated for its CT appearance and histological findings. The number of calcifications observed on CT varied from one to six. Most were eccentric, but some calcifications in four cases were within the more central portion of the nodules. Overall, in six of seven cases the calcifications were histologically estimated to be due to preexisting old granulomatous fibrotic changes or fragments of bronchial cartilage incorporated within the growing tumors. In only one case were the calcifications psammoma bodies within the tumor. We conclude that punctate calcifications in lung cancers correspond mostly to preexisting calcified granuloma or degenerated bronchial cartilage.