Abstract
The authors report that cancer of the lung constitue a larger part as the cause of left recurrent nerve paralysis of unknown etiology, which is greater in incidence than the ones caused by cancer of the thyroid gland.
Cancer often involves the hilar lymph nodes either by infiltration or metastases, which is often elusive in radiological examination. A careful and contineous observation is needed for paralysis of the recurrent nerve on the left side.
