Postoperative remission of non-invasive lactotroph pituitary tumor: A single-center experience.

BACKGROUND: Dopaminergic agonists (DA) are the first-line treatment in lactotroph pituitary tumor but treatment usually needs to be life-long. After surgical transsphenoid resection, remission rates range from 60 to 90%, with low morbidity. OBJECTIVE: The objective was to evaluate outcome of surgical treatment of selected non-invasive prolactinoma, and to identify factors associated with long-term remission. METHOD: Early postoperative (3 months) and last follow-up data for non-invasive lactotroph tumors operated on in intention-to-cure in our center between 2008 and 2017 were retrospectively reviewed: prolactin (PRL) level, DA treatment, pituitary function, and MRI data. Remission was defined as PRL plasma level below the upper limit of normal without DA treatment. RESULTS: Fifty-three of the 60 patients (32 of the 33 microadenomas) were in remission at 3 months and 46 (28/33 microadenomas) at last follow-up 22.7 months (range, 1.1-126.5 months) after surgery. Five-year recurrence-free survival was 77.5% [65.8-91.2]. Male gender, larger tumor size at diagnosis and before surgery, and higher plasma PRL level at diagnosis were all significantly associated with lower remission rates on univariate analysis. Transient diabetes insipidus and hyponatremia occurred in 2 and 5 patients respectively. One case of isolated thyrotroph insufficiency was observed. During follow-up, 13 women became pregnant (12 spontaneously). CONCLUSION: This cohort confirmed the high remission rate of lactotroph tumors after surgery in a selected population, with limited morbidity, and conserved pituitary function in almost all cases.