Endocrine Abstracts

Introduction: Dopamine agonists (DA), reference treatment for microprolactinomas, rarely allow long term remission. The performance of endoscopic pituitary surgery should be examined as first-line treatment.

Objective: To evaluate the remission rate of microprolactinoma operated by endoscopic transphenoidal approach

Methods: We retrospectively studied the surgical results of the 35 microprolactinomas operated between 2010 to 2017 in our institution by a single surgeon (EJ). We analyzed the immediate (3months) and long term (last follow-up) remission rates, as well as the post-operative complications.

Results: The sex ratio was 7.8 (F=31) and the mean age at diagnosis was 27±8 years. Seven patients were immediately operated (patient choice), 28 received pre-operative DA (median 7.5 (0.2–188) months)) with cabergoline (n=17), quinagolide (n=6), bromocriptine (n=3), or indetermined (n=2). DA achieved prolactin normalization in 13/28 patients (46%). Surgical indication was DA intolerance (n=13), patient choice (n=13), resistance despite DA high dose (n=2). Most of adenomas were noninvasive for cavernous or sphenoid sinus (34/35) and non-proliferative (grade 1a n=26/35). No patient presented pituitary deficiency after surgery. Two presented hyponatremia due to SIADH with spontaneous resolutions in few days. Other complications included sinusitis (n=3) and one cerebral fluid leak without meningitis. At 3-months (n=33), remission rate was 97% (32/33): one patient, intolerant to high dose DA, with 9 mm invasive tumour before surgery, required post-operative Cabergoline treatment (0.5 mg/day). Long term remission rate (n=33) after a median follow-up of 1.3 year [0.25; 9.4] was 81.8% (27/33). Only two patients required DA to control clinical symptoms, 3 presented slight elevation of prolactin level without clinical symptoms or tumor recurrence. The median time before recurrence was 5.4 years [0.7; 9.4]. All women (29) recovered a normal gonadotropic function, allowing 6 pregnancies in 5 patients. Sex, age at diagnosis, pre-operative DA,prolactin level, tumor size, cavernous sinus invasion (radiological or operative) and grade tumor were not significantly associated with long-term remission using univariate analysis. However, all recurrent patients were DA pretreated.

Conclusion: This study showed a high long term remission rate compared to the rate of prolactin normalization under medical treatment, while post-operative complications were acceptable. Surgery could be considered as first line treatment in microplactinomas. Remission rate being higher without preoperative DA, surgery may be proposed before any medical treatment.