Identify  ectopic gonadotropin as a cause of gynecomastia.

Explanation:

Gynecomastia is due to 3 physiologic states, newborn, puberty and old age.

Non physiologic states include the following-Obesity can also be related, Drugs such as Cimetidine, Spironolactone and Digoxin are also favorites on tests, Diseases such as testicular atrophy due to any cause - be it primary testicular failure or secondary ( mumps) or a hyperoestrogenic state like Liver cirrhosis.

Tumors that produce gonadotrophins like seminoma(hcg) also cause gynecomastia therefore always examine the testes( tumors of testes display loss of deep pain when you press the testes!)