Clinicopathological analysis of primary lung carcinoma with heterotopic ossification.

Pulmonary heterotopic ossification is an unusual event. The relationship between ossification and lung carcinoma is unclear. The present study analyzed clinicopathological features of primary lung carcinoma with heterotopic ossification. We reviewed 2269 surgically resected primary lung carcinomas and identified 33 with heterotopic ossification, including 15 cases with intratumoral heterotopic ossification (IHO) and 18 cases with extratumoral heterotopic ossification (EHO). All cases with IHO were adenocarcinomas and 10 of 15 (66.6%) cases had confirmed positive mucin staining in the tumor cells. Cases with EHO could be divided into three patterns, and each pattern is potentially associated with the background conditions of lung parenchyma. Immunohistochemistry, BMP-2 production was present in 13 of 15 (86.7%) cases with IHO, although, only 4 of 17 (23.5%) cases with EHO. A prognostic analysis revealed no statistically significant difference to be observed between adenocarcinomas with IHO and without IHO. The present study suggested that IHO associated with adenocarcinomas and BMP-2 production in the tumor cells, whereas EHO was not associated with the biology of the carcinoma.