Primary bronchial carcinoma is a very common malignancy. The vast majority of cases in smokers and or those who inhale other people’s smoke( passive smokers). Other risk factors include exposure to airborne ducts and the presence of lung fibrosis. Very frequently,a metastatic tumour elsewhere causes symptoms before the lung has been discovered and therefore the prognosis of this type of cancer is usually poor.
The tumour usually develops in a main bronchus,forming a large friable mass which projects into the lumen,sometimes causing obstruction. Mucus then collects and predisposes to development of injection. As the tumour grows it may erode a blood vessel,causing haemoptysis.
SPREAD OF BRONCHIAL CARCINOMA.
LOCAL SPREAD:This may be within the lung,to the other lung or to mediastinal structures eg blood vessels,nerves,oesophagus.
LYMPHATIC SPREAD: Tumour fragments spread along lymph vessels to successive lymph nodes in which they may cause metastatic tumours.
BLOOD SPREAD: Tumour cells can enter the blood if a blood vessel is eroded by a growing tumour. The most common blood-borne sites are the liver,brain,adrenal glands,bones and kidneys.
