What is Pancoast Syndrome?

Pancoast syndrome is a complication of lung cancer that occurs in patients with cancer in the top part of the lung, and is a sign that the cancer is progressing very rapidly. The syndrome symptoms consist of shoulder, arm and chest pain with an associated Horner syndrome (a drooping eyelid, lack of sweating on one side of the face and a contracted pupil in the eye). Death usually follows soon after the syndrome is diagnosed, says Dr. Warwick Carter in his book The Complete Family Medical Guide.