Which statement is true about pituitary adenomas?

Which statement is true about pituitary adenomas?

• A. Microadenomas <10 mm secreting prolactin may be treated with bromocriptine
• B. Macroadenomas always secrete prolactin
• C. All pituitary adenomas shrink spontaneously
• D. Prolactin levels are not affected by bromocriptine

Answer: (A)

Dopamine agonists are first-line therapy for prolactin-secreting pituitary tumors. Prolactin release from lactotroph cells is inhibited by dopamine, so medications like bromocriptine bind D2 receptors and suppress prolactin production while often shrinking the tumor. When the adenoma is small, less than 10 mm (a microadenoma), this medical approach is especially effective, making bromocriptine a valid treatment option in these cases. Understanding the other statements helps clarify why this is true. Not all pituitary adenomas secrete prolactin—macroadenomas can be nonfunctioning or secrete other hormones—so the claim that macroadenomas always secrete prolactin is incorrect. Spontaneous shrinking of pituitary adenomas is not a typical behavior; most do not shrink on their own. Finally, bromocriptine lowers prolactin levels; saying prolactin levels are not affected would be inaccurate because the drug’s primary effect is to suppress prolactin release.

Dopamine agonists are first-line therapy for prolactin-secreting pituitary tumors. Prolactin release from lactotroph cells is inhibited by dopamine, so medications like bromocriptine bind D2 receptors and suppress prolactin production while often shrinking the tumor. When the adenoma is small, less than 10 mm (a microadenoma), this medical approach is especially effective, making bromocriptine a valid treatment option in these cases.

Understanding the other statements helps clarify why this is true. Not all pituitary adenomas secrete prolactin—macroadenomas can be nonfunctioning or secrete other hormones—so the claim that macroadenomas always secrete prolactin is incorrect. Spontaneous shrinking of pituitary adenomas is not a typical behavior; most do not shrink on their own. Finally, bromocriptine lowers prolactin levels; saying prolactin levels are not affected would be inaccurate because the drug’s primary effect is to suppress prolactin release.