Multiple primary bronchogenic carcinomas of the lung

The problem of multiple primary bronchogenic carcinomas in a single patient is not well known to radiologists. Six patients who exemplified the clinical, radiographic, and pathologic difficulties in diagnosis are reported. The most frequent pathologic associations are squamous carcinoma and squamous carcinoma, squamous carcinoma and small-cell carcinoma, and squamous carcinoma and adenocarcinoma. The previously undescribed association of small-cell carcinoma and bronchioloalveolar cell carcinoma was present in one of six patients. While many patients have a synchronous presentation, the tumors are metachronous in 66%. Since the incidence of second primary carcinoma increases with time, close long-term monitoring is recommended.