Lung carcinomas most frequently metastasize to -

Ref:Textbook of pathology (Harsh mohan) 6th edition,page no.502 Bronchogenic carcinoma can invade the adjoining structures directly, or may spread by lymphatic and haematogenous routes: 1. Direct spread. The tumour extends directly by invading through the wall of the bronchus and destroys and replaces the peribronchial lung tissue. As it grows fuher, it spreads to the opposite bronchus and lung, into the pleural cavity, the pericardium and the myocardium and along the great vessels of the hea causing their constriction. Extension of the cancer located at the apex of the lung into the thoracic cage may involve brachial plexus and the sympathetic chain causing pain and sensory disturbances, so called Pancoast's syndrome. 2. Lymphatic spread. Initially, hilar lymph nodes are affected. Later, lymphatic metastases occur to the other groups leading to spread to mediastinal, cervical, supraclavicular and para-aoic lymph nodes. Invasion of the thoracic duct may produce chylous ascites. 3. Haematogenous spread. Distant metastases blood stream are widespread and early. The sites affected, in descending order of involvement, are: the liver, adrenals, bones, pancreas, brain, opposite lung, kidneys and thyroid