Double primary lung cancers: with special reference to their exfoliative cytology and to the rare, malignant "mixed" tumor of the salivary-gland type

Two autopsy cases are reported in which double primary cancers of the lung had been strongly or definitely suspected before death by demonstration of two different types of malignant cells in the sputum as well as in smears of aspirates from pleural fluid and/or mediastinal tumor. By exfoliative cytology, one case was characterized by carcinoma cells of the small-cell type plus the large-cell and/or adenocarcinoma type; the other displayed small-cell-type and squamous-cell-type malignant cells. The autopsies definitely revealed in the first case an anaplastic carcinoma of the small-cell type in the left bronchus and a salivary-gland-type malignant "mixed" tumor in the right lower lobe and in the second case an anaplastic carcinoma of the small-cell type in the right upper lobe and a squamous-cell carcinoma in the left upper lobe. The frequence of occurrence and pathologic diagnosis of double primary lung cancers are reviewed and discussed. A rare type of lung cancer, salivary-gland-type malignant "mixed" tumor, is given special reference.