Bronchial adenoma. Light micrograph (LM) of a section of an adenoma of the bronchus. Bronchial mucous gland adenoma (BMGA) is a very uncommon, benign tumour, defined as a proliferation of seromucous glands in the bronchial lamina propria, without cellular atypia, usually arising in the proximal airways. This tumour occurs equally in male and female gender, and at all ages. Clinical manifestations are the result of bronchial obstruction due to tumour growth and include haemoptysis (expectoration of blood), cough, dyspnoea (laboured breathing), wheezing, and sometimes pneumonia. Magnification: x 50 when printed at 10 centimetres wide. Human tissue