Solitary lung mass / pulmonary nodule

What it is

Underlying lung disease, lung cancer among it, is often suspected first from findings outside the chest. Digital clubbing, sudden-onset arthropathy of the wrist and hand joints, and hyponatremia from ectopic ADH secretion all point back to the lung, and the chest x-ray is the appropriate initial study for identifying the underlying cause.

Causes and risk

The causes of clubbing are grouped as CLUBBING: cyanotic heart disease and cystic fibrosis; lung cancer and lung abscess; ulcerative colitis; bronchiectasis; benign mesothelioma; infective endocarditis and idiopathic pulmonary fibrosis; neurogenic tumors; and gastrointestinal disease. Hypertrophic pulmonary osteoarthropathy is the subset of hypertrophic osteoarthropathy in which the clubbing and the arthropathy are attributable to underlying lung disease such as lung cancer, tuberculosis, bronchiectasis or emphysema, so an extensive smoking history moves lung cancer to the front of that list.

How it presents

Clubbing has four grades:

• Grade 1: normal appearance and angle, with nail bed fluctuation.
• Grade 2: obliteration of the Lovibond angle.
• Grade 3: increased curvature of the nails, the parrot beak or drumstick appearance.
• Grade 4: swelling in all directions, that is hypertrophic osteoarthropathy, the most advanced stage.

The angle at a normal finger is 160°, and a clubbed finger is above 180°. Clubbing appearing together with sudden-onset arthropathy in a chronic smoker is suggestive of hypertrophic osteoarthropathy, and the arthropathy commonly affects the wrist and hand joints. Hoarseness belongs to it. The differential of persistent hoarseness in a patient who smokes includes both laryngeal cancer and lung cancer, and in lung cancer it is a malignancy involving the recurrent laryngeal nerve along its course under the arch of the aorta and back to the larynx.