Prolactinoma: Indications for surgery.

From Lewis S Blevins Jr., MD  –  Although dopamine agonist drugs are available to treat prolactinomas I believe some patients with these tumors are probably best treated surgically. Of course, surgery should be performed by experienced pituitary surgeon to ensure that the best outcomes are achieved. In my opinion, surgery only “makes sense” when patients can be related an approximate 90 to 95% cure rate for microsdenomas and an 80% cure rate for intrasellar macroadenomas. Prolactinomas that have escaped the confines of the sella are probably best treated medically but sometimes surgery is required to debulk them and occasional patients are rendered disease free.

So, here are my indications….

1. Failure to normalize the serum prolactin concentration with dopamine agonist drugs. This is a problem for about 10% of microprolactinomas and 15 to 25% of patients who have macroprolactinomas.

2. Failure to significantly reduce the size of the prolactinoma with dopamine agonist drugs. This is more of an issue for macroadenomas. Fifty per-cent of tumors regress by 50% or more, 25% of tumors will regress by 25%, and 25% of patients have minimal regression. Those who have persistent anterior pituitary hormone dysfunction and or visual field deficits in the setting of minimal regression probably should undergo surgery.

3. Increase in the size of a prolactinoma during treatment with dopamine agonist drugs. This is a rare occurrence but does happen. I have seen it several times in my career.

4. Intolerance to dopamne agonist drugs. Intolerance is more common with bromocriptine than it is with cabergoline. Fifteen to 30% of patients develop side effects of these medications but only about 3 to 5% of patients need to discontinue cabergoline.

5. In preparation for pregnancy because of the 5 to 15% risk of tumor growth during pregnancy. This borders on patient preference.

6. When there is a high likelihood of cure and, thus, the opportunity to avoid lifetime medication in younger patients.

7. Patient preference when there is a possibility for cure. I am one of those physicians who believes that patients should play a role in decision-making and allowed to make informed choices. Some tumors are amenable to surgery and, when the neurosurgeon has considerable expertise, surgery is reasonable. The benefits must always greatly exceed the risks.

8. Repair of a CSF leak that might result from regression of a prolactinoma. This is unusual but does happen. If the surgeon has to go in and repair a leak they might as well try to resect as much tumor has is possible.

9. To clarify a diagnosis. Sometimes it is not clear whether a patient has a prolactinoma, an atypical prolactinoma, or a macroadenoma with stalk effect- hyperprolactinemia. Histologic examination of resected tissue is often necessary to determine the actual diagnosis and plan for a course of treatment.

10. When a tumor also co- secretes growth hormone. One third of Acromegalic patients co-secrete prolactin. Sometimes, hyperprolactinemia is the index diagnosis and acromegaly is recognized after careful further examination and laboratory analysis. Surgery is still the mainstay of therapy for acromegaly with or without hyperprolactinemia.

© 2014, Pituitary World News. All rights reserved.