Pancoast tumors, a lung cancer that forms at the very top of the lung, can be diagnosed late because they often first appear as shoulder pain, arm numbness or a drooping eyelid on one side rather than coughing or shortness of breath.
A 71-year-old woman who visited an orthopedic clinic for shoulder pain was diagnosed with a Pancoast tumor after a computed tomography (CT) scan, according to a case report published in BMJ Case Reports on the 2nd. A Pancoast tumor grows at the top of the lung and presses on the bundle of nerves running to the neck and arm. When those nerves are compressed, symptoms appear in the shoulder, arm and face rather than the chest. Doctors advise seeking care if such symptoms persist for more than two weeks.
The hallmark symptom is severe pain in the shoulder on the side where the tumor has formed. The pain spreads down the arm toward the little finger and can stop near the wrist. Patients may also lose strength in the arm and hand, or feel numbness and dulled sensation. The patient in the case above reported reduced sensation and muscle strength in the arm along with worsening respiratory symptoms. A bone scan showed the tumor in the right lung had spread to the chest wall and destroyed ribs.
Up to 50% of patients develop Horner syndrome from damage to the sympathetic nerves. It is marked by a drooping eyelid and a constricted pupil on the same side, along with an absence of sweating on one side of the face. The West Indian Medical Journal reported the case of a 59-year-old man who was diagnosed with the tumor after being examined for a drooping right eyelid, facial anhidrosis, pupil constriction, weight loss and loss of appetite. In some cases the tumor is found through Horner syndrome alone, without coughing, coughing up blood or chest pain.
The tumor is rare. One overseas review paper reported it accounts for less than 5% of bronchial lung cancers, while other literature put the figure at 5% to 8%. According to the Cleveland Clinic in the United States, most cases are diagnosed after the tumor has already invaded the chest wall or sympathetic nerves, or spread to the brachial nerves or spinal cord. Diagnosis relies on chest X-rays, CT, magnetic resonance imaging (MRI) and needle biopsy. Anyone with unusual symptoms should see a pulmonologist and a medical oncologist.
For patients eligible for surgery, the standard treatment is to shrink the tumor with chemoradiation therapy before the operation and then remove it. A review paper by Greek researchers put the five-year survival rate at 54% to 77% for patients whose tumors were completely removed after this treatment. When surgery is not feasible or the cancer has spread, radiation is used to shrink the tumor and ease symptoms. Prevention calls for quitting smoking, avoiding secondhand smoke and checking for exposure to harmful substances such as asbestos. Those with a family history should get regular screenings.
