Rare pulmonary tumors - a review of 32 cases.

In a review of pulmonary tumors diagnosed at our institute from 1976 to 1995, we found 20 malignant and 12 benign rare tumors, which accounted for 0.57 and 0.34% of all pulmonary tumors, respectively. The histological types of these rare malignant tumors were malignant lymphoma (6/20), carcinosarcoma (3/20), mucoepidermoid carcinoma (2/20), bronchial gland mixed tumor (2/20), adenocystic carcinoma (1/20), myoepithelioma (1/20), leiomyosarcoma (1/20), epitheloid hemangioendothelioma (1/20), hemangiopericytoma (1/20), malignant melanoma (1/20) and choriocarcinoma (1/20). Benign rare tumors involved papilloma (3/12), lipoma (3/12), leiomyoma (3/12), adenoma (1/12), fibroma (1/12), and meningioma (1/12). The clinical and pathological features of malignant tumors were roughly the same as those of common pulmonary carcinomas. In contrast, benign tumors were never larger than 3 cm and were more commonly located in the central parts of the lung, which explained the relatively frequent symptoms of wheezing and fever associated with obstructive pneumonia.