Surgery as first-line treatment for prolactinoma? Discussion of the literature and results of a consecutive series of surgically treated patients

Initial treatment for prolactinoma is usually conservative with dopamine agonists. However, the duration of treatment is often lifelong and can be associated with significant side effects. Surgical outcomes are usually favorable and treatment complications low, raising the question whether surgical therapy should be included earlier in the treatment of prolactinoma. The aim of this study was to analyze the outcome of surgical resection of prolactinomas at our institution, to compare it with other published surgical and conservative series and to discuss the role of surgery in modern prolactinoma therapy. The authors reviewed a database of single-center consecutively operated prolactinoma cases and analyzed the extent of resection (EOR), endocrinological and neurological outcomes, and complications. Thirty patients were analyzed. Mean patient age was 37.2 ± 15.5 years (range 16-76) and consisted of 17 (56.7%) females and 13 (43.3%) males. Twenty-one patients (70%) failed medical therapy, the main reasons being intolerable side effects in 11 cases (52.4%) and insufficient response in 10 cases (47.6%). Nine patients (30%) received no medical treatment prior to surgery, of which five (55.6%) were operated because of pituitary apoplexy, two (22.2%) because of acute visual deterioration and two (22.2%) refused medical treatment and opted for surgery as first-line treatment. Of the 30 operated tumors, 56.7% (n = 17) were microadenomas, 30% (n = 9) were macroadenomas (≥ 10 mm), and 13.3% (n = 4) were giant adenomas (≥ 40 mm). GTR was achieved in 75% (n = 21) of cases. The overall remission rate was 63.3%. MRI showed a residual tumor in seven patients (25%), typically with invasive growth. Postoperative CSF leaks did not occur. Mean follow-up was 34.9 ± 60.3 months (range 0-246 months). Endocrine remission was defined as a morning fasting basal PRL level of 22.3 < ng/mL and measured at the last available follow-up. Postoperative Prolactine levels were missing in three patients. Our analysis describes a highly selected sample with a disproportionate number of larger, invasive tumors and emergency cases. Nevertheless, the results are satisfactory and comparable with other published series. The consistently good results of transphenoidal surgery, especially for microprolactinomas, have led to a greater acceptance of surgery in the treatment of prolactinomas in recent years. The timing of surgery in each individual case must be determined by a multidisciplinary team to ensure the best possible outcome.