[A case report of endobronchial lipoma]

Endobronchial lipomas are rare benign tumors of the lung. Nineteen cases have been reported in Japan. We present a case of endobronchial lipoma obstructing the left B4b and chronic saccular bronchiectasis throughout the left upper lobe. A 42-year-old man, 174 cm tall and weighing 47 kg, was referred for investigation of an abnormal chest X-ray film. He had a history of pneumonia and pyothorax in infancy. The chest X-ray film showed linear densities and ill-defined, irregular opacities in the upper-middle lung field. CT scan and tomographic studies showed multiple cystic spaces in the left upper lobe in which the volume was diminished. An angiogram of the left bronchial artery showed peripheral hypervascularity in the left upper lobe and systemic-to-pulmonary artery shunt. Fiberoptic bronchoscopy revealed a smooth, pink mass obstructing B4b. Biopsy specimens were insufficient for histological diagnosis. Preoperatively, an inflammatory polyp in association with chronic saccular bronchiectasis was suspected. Left upper lobectomy was performed on January 13, 1989. Gross examination of the resected specimen showed a pedunculated polypoid mass, 1.5 X 1.2 X 0.6 cm, attached to the bronchial mucosa of B4bii and saccular ectatic changes of bronchi not only in the lingular division but also in upper division. Microscopically, the endobronchial tumor consisted of mature adipose tissue covered with columnar bronchial epithelium. The fat was fairly well localized in the submucosa, but was not encapsulated and did not enclose glands or smooth muscle fibers. The endobronchial lipoma was thought to originate in the bronchus of chronic saccular bronchiectasis.