Oncocytes of bronchial secretory glands were investigated in 50 operated cases with pulmonary diseases. In 28 cases (56%) oncocytes were found in the main bronchial wall or lobar bronchial wall. They were observed more commonly with increasing age.
On light microscopy oncocytic glands were divided into 3 types, i.e. type I gland full of oncocytes, type III gland with few oncocytes and type II which showed intermediate amounts of oncocytes.
Ultrastructurally we found normal oncocytes which were fully packed with hyperplastic mitochondrias and incomplete oncocytes, derived from serous gland cell, in which the cytoplsm was filled with a large amount of mitochondrias.