The best treatment for this patient is L-thyroxine, because she suffers from severe hypothyroidism. Amenorrhea is a symptom of hypothyroidism, especially in severe cases of the disorder, and can be accompanied by hyperprolactinemia and galactorrhea. The enlargement of the pituitary gland is secondary to the overproduction of thyrotropin, which is a response to decreased levels of thyroid hormone levels. When patients are treated with thyroid replacement therapy, all manifestations of hypothyroidism disappear, and treatment for hyperprolactinemia is unnecessary.
