Pulmonary scar carcinoma. A case with two primaries.

The presence of scar tissue associated with peripheral pulmonary carcinomas has always evoked considerable interest. This report concerns a unique case of a 55-year-old white oil-field worker whose right pneumonectomy specimen disclosed two primary pulmonary scar cancers, involving both upper and lower lobes. Both carcinomas arose at the margins of pleural-based scars. The malignancy in the right upper lobe was a 2.5-cm large cell carcinoma, while that in the right lower lobe was a 2.0-cm adenocarcinoma. The bronchial and hilar lymph nodes were free of metastases. One month following pneumonectomy the patient suffered a cardiac arrest, and necropscopic examination failed to reveal evidence of metastases. Controversy continues concerning whether the scar precedes or follows the development of peripheral pulmonary carcinomas. Several recent studies favoring the latter theory have suggested that the scar is immunologically related to the carcinoma. In the current case, the pleural-based upper lobe scar was associated with an old, inactive granuloma, while the lower lobe pleural-based scar disclosed no clue as to its origin. The adenocarcinoma in the lower lobe might possibly be immunologically related to its associated scar; however, it would appear difficult to account for the scar of the upper lobe large cell carcinoma by a similar mechanism.