Two histologically different primary carcinomas of the lung. A review of the literature and presentation of a case

A review of the literature on the subject of double primary bronchogenic carcinoma has been made. Only cases which adhere to the criterion of total difference in histologic appearance of the two tumors have been considered. It is felt that, although rigid, this criterion must be met in order to justify the diagnosis of double primary tumors and totally rule out the possibility of metastasis as the source of the second tumor. Thirty‐three well‐documented cases which met this criterion were found recorded in the literature. In addition one more recent case of double primary bronchogenic carcinoma is presented.