Statistical analysis of malignant tumors detected as the cause of vocal cord paralysis.

It is well known that vocal cord paralysis is sometimes the only sign of an otherwise symptom-free malignant tumor. We report 69 cases of vocal cord paralysis caused by malignant tumor experienced at our clinic over the past 18 years. They consisted of 28 cases of thyroid cancer, 21 lung cancer, 14 esophageal cancer, 3 mediastinal tumors and 3 tumors of miscellaneous origin: 41 cases were male and 28 female. In the 65 patients with unilateral paralysis, the left side was affected in 45 and the right in 20. The remaining 4 patients had bilateral paralysis. There was a marked sex difference in the origin of malignant tumors; the incidence of lung cancer was higher in males with paralysis on the left side, while that of thyroid cancer was higher in females. Ultrasonography (US) of the neck, chest X-ray, CT scan of the chest and contrast esophagography should be performed for the detection of malignant tumors in cases with left paralysis, while US of the neck and chest X-ray appear to be sufficient in cases of right paralysis.