Bronchial adenoma, firstly described by Muller[1882] had been reported on the subject stressed their benign nature prior to 1940`s, but these tumors including carcinoid tumor, mucoepidermoid carcinoma, adenoid cystic carcinoma, pleomorphic adenoma are now known to possess the various degree of malignant natures from benign course, low grade malignant potential to distant lymphatic or hematogenous metastasis or combination. Although histologically diffeerent, four varieties except carcinoid tumor which is a spectrum of neu-roendocrine tumor originating Kulchitsky cell of the bronchial epithelium and form the part of the APUD tumor spectrum, are morphologically and in many respects clinically similar to the corresponding tumor of the salivary gland is a specific varient of adenocarcinoma that occurs most commonly in the major and minor salivary gland and less frequently tra-cheobronchial tree, esophagus etc. To better understand the clinical characteristics and assess more precisely the malignat nature of bronchial adenoma, we studied 17 cases of bronchial adenoma, which had been experienced at the Department of Thoracic and Cardiovascular surgery of Catholic University Medical College from April 1977 to september 1991. Seventeen cases of bronchial adenoma consist of 2 carcinoid tumors, 6 adenoid cystic carcinomas, 8 mucoepidermoid carcinomas and one pleomorphic adenoma. There is a slight predominace of male patients[10/17] and the age of pt studied varied with a higher incidence occurring between the ages of 40 years and 60 years[mean age, 46.5 years]; the youngest being 15 years and oldest 69 years. Their leading complaints were hemoptysis[4], exertional dyspnea[8], fever & chilness [4], and symptoms mimicking the bronchial asthma[4]. Diagnosis was aided by the radiologic studies such as chest X-ray, polytomography, CT scan, brochography and bronchoscopy. The preferred locations of fumor were in the trachea[4], main stem bronchus[3], bronchus intermedius[3], bronchus of RUL[2], LUL[1], RLL[1], LLL[3] with no peripheral location. Modalities of treatments were single or combination of surgical resection, radiation therapy, chemotherapy. Complete resections were permitted in 12 cases with late recurrences of 4 cases ranging from 6 months to 10 years: pneumonectomy[4], lobectomy[4], bil-obectomy[2], sleeve resection[2]. Gross findings of resected specimens in 14 cases showed that 4 cases were polyp-like pedunculated mass[entirely intraluminal mass] with intact mucosa, 8 cases were broad-bas-ed sessile mass[predominatly intraluminal] and the main portions were located below the mucosa similar to tip of iceburg[predominantly extraluminal] in 2 cases. Follow-up information was availble in all 17 cases ; eight were alive without evidence of disese ranging from 1 month to 13 years. But seven cases died of the causes related to tumor[6 cases within 12 months, one case 10 years after pneumonectomy]. We concluded that 8 cases[47%] of 17 cases were metastasizing bronchial adenoma and precise survival rate cannot be answered by the scanty materials available for study.