A 69-year-old man comes to the office due to progressive pain beneath his right scapula and in his right arm for the last several months. He has taken over-the-counter analgesics, which provide short-term relief, but the pain has become more severe and awakens him at night. The pain is associated with numbness in his right forearm extending up to the tips of the fourth and fifth fingers. The patient has also had persistent nonproductive cough and lately has been coughing up streaks of blood. He has a history of hypertension, gastroesophageal reflux disease, and osteoarthritis. He has smoked 2 packs of cigarettes daily for more than 40 years but recently cut down to 4 or 5 cigarettes a day. Which of the following is the most likely cause of this patient's symptoms?
This patient with an extensive smoking history who now has hemoptysis and shoulder pain likely has lung cancer, which can be associated with symptoms due to local or distant spread. Pancoast syndrome is caused by a tumor at the lung apex. Such tumors often arise in the superior sulcus (groove formed by the subclavian vessels). The apical location allows for extensive local tumor spread. Invasion of surrounding structures can cause the following:
Shoulder pain radiating toward the axilla and scapula (most common presenting symptom). It occurs due to involvement of the lower brachial plexus. Other associated symptoms include arm paresthesia, weakness, and muscle atrophy.
Horner syndrome occurs due to involvement of the cervical sympathetic ganglia. Symptoms include ipsilateral ptosis, miosis, and anhidrosis.
Upper extremity edema may be due to compression of subclavian vessels.
Spinal cord compression and paraplegia can result from tumor extension into the intervertebral foramina.
(Choice A) Squamous cell carcinoma is associated with parathyroid-related peptide secretion and hypercalcemia. Cushing syndrome and syndrome of inappropriate antidiuretic hormone secretion can accompany small cell carcinoma of the lung.
(Choice B) Centrally located lung cancers (squamous cell and small cell carcinomas) frequently obstruct the main bronchi, producing dyspnea and cough. Airway obstruction would not cause shoulder pain or muscle atrophy.
(Choice C) Anterior mediastinal masses include thymoma, teratoma, thyroid cancer, and (terrible) lymphoma ("terrible Ts"). They are less likely to lead to hemoptysis or brachial plexus involvement.
(Choice D) Lung cancers are associated with a number of autoimmune syndromes, most commonly Lambert-Eaton (progressive proximal muscle weakness, often in the legs).
(Choice E) Pericardial effusions are characterized by dyspnea, distended neck veins, distant heart sounds, and - particularly if tamponade is present - pulsus paradoxus (decrease in systolic blood pressure >10 mm Hg during inspiration).
(Choice F) A pleural effusion can lead to dyspnea and irritate the mediastinal and diaphragmatic pleura, causing referred shoulder pain (via the phrenic nerve); however, it would not cause hemoptysis.
Educational objective:
Tumors located in the lung apex (superior sulcus) are called Pancoast tumors. Invasion of surrounding structures can lead to ipsilateral Horner syndrome, rib destruction, atrophy of hand muscles, and pain in the distribution of C8, T1, and T2 nerve roots.