Pituitary surgery for small prolactinomas as an alternative to treatment with dopamine agonists

Abstract

Despite the fact that consensus guidelines recommend long-term dopamine agonist (DA) therapy as a first-line approach to the treatment of small prolactinoma, some patients continue to prefer a primary surgical approach. Concerns over potential adverse effects of long-term medical therapy and/or the desire to become pregnant and avoid long-term medication are often mentioned as reasons to pursue surgical removal. In this retrospective study, 34 consecutive patients (30 female, 4 male) preferably underwent primary pituitary surgery without prior DA treatment for small prolactinomas (microprolactinoma 1–10 mm, macroprolactinoma 11–20 mm) at the Department of Neurosurgery, University of Bern, Switzerland. At the time of diagnosis, 31 of 34 patients (91%) presented with symptoms. Patients with microprolactinomas had significantly lower preoperative prolactin (PRL) levels compared to patients with macroprolactinomas (median 143 μg/l vs. 340 μg/l). Ninety percent of symptomatic patients experienced significant improvement of their signs and symptoms upon surgery. The postoperative PRL levels (median 3.45 μg/l) returned to normal in 94% of patients with small prolactinomas. There was no mortality and no major morbidities. One patient suffered from hypogonadotropic hypogonadism after surgery despite postoperative normal PRL levels. Long-term remission was achieved in 22 of 24 patients (91%) with microprolactinomas, and in 8 of 10 patients (80%) with macroprolactinomas after a median follow-up period of 33.5 months. Patients with small prolactinomas can safely consider pituitary surgery in a specialized centre with good chance of long-term remission as an alternative to long-term DA therapy.

THERAPY OF ENDOCRINE DISEASE: Surgery in microprolactinomas: effectiveness and risks based on contemporary literature

“…Lower postoperative remission rates (40 -63%) have been reported in three series with, however, small number of patients (5,27,32) affecting the estimation of the relevant rates (25,26,27). Most studies with mean/median follow-up period ranging between 12 and 84 months suggest that recurrence of the hyperprolactinaemia is observed between 0 and 13% of the cases (15,16,17,20,23). In one study, however, a recurrence rate of 33% was described during a median observation period of 33 months (22).…”

“…Series confirming that the operations were carried out by one or two surgeons in a single center or by surgeons each performing 80 pituitary operations per year mostly show higher remission rates (82 -100%) (13,14,15,16,18,20,30,31,32) pointing out the importance of surgical expertise. Other factors affecting biochemical remission are not clearly defined specifically for the microprolactinomas as the reported results include analyses for both micro-and macroprolactinomas.…”

“…The reported peri-and postoperative complications in microscopic series include mortality 0% (13,15,16,17,19,20,21,22,24,27), visual deterioration 0% (13,15,27), and other neurosurgical complications 0 -1.8% The study included 35 patients with prolactinoma (13 with micro-and 22 with macroprolactinoma). Eight patients had been previously operated, but it is not clarified if among them there were ones with microprolactinoma.…”

“…The outcomes of pituitary function are given in Table 3, and in all (15,19,20,22,24,26) but one (with a very small number of patients) (23) studies, they look rather optimal; hypogonadism or permanent diabetes insipidus was found between 0 and 6%.…”

Outcomes of transsphenoidal surgery in prolactinomas: improvement of hormonal control in dopamine agonist-resistant patients

“…Few studies have recently re-examined the outcome of patients treated by transsphenoidal surgery for a prolactinoma (17,18,19,20,21,22,23,24). They reported variable remission rates for microprolactinomas (between 50 and 93%) and macroprolactinomas (between 30 and 80%), as well as a highly variable frequency of recurrences between 5 and 58%, the latter variability being mainly dependent on the length of the follow up and the indication retained for surgery.…”