Functional Gonadotroph Adenomas in Male Patients: Clinical Characteristics, Surgical Outcomes, and Hormonal Follow-up

Abstract

Background and objectives: Functional gonadotroph adenomas (FGAs) are rare pituitary neuroendocrine tumors derived from the steroidogenic factor 1 (SF-1) lineage that present clinically with elevated serum levels of follicle-stimulating hormone (FSH) and/or luteinizing hormone (LH). While previous research has predominantly featured female patients, this study specifically aims to better understand the clinical characteristics and postoperative outcomes of FGAs in male patients.

Methods: A retrospective review of medical records from a single institution, encompassing 1306 pituitary adenomas, identified 12 male patients who underwent transsphenoidal resection for FGAs.

Results: Mean (SD) age was 66.5 (9.4) years. Mean (SD) size was 28.8 (21.6) mm. Preoperatively, all patients exhibited elevated FSH (mean [SD] = 21.9 (7.0) mIU/mL, range = 13.7-34.9 mIU/mL, normal = 1.5-12.4 mIU/mL). Mean (SD) preoperative LH was 6.5 (5.9) mIU/mL (range = 1.3-20.9 mIU/mL, normal = 1.8-8.6 mIU/mL), and it was elevated in 2 patients. 3 patients possessed preoperative testosterone dysfunction (2 with low total and free testosterone, 1 with low total testosterone). All patients were symptomatic preoperatively, with fatigue, headache, and visual problems being the most common. Gross total resection was achieved in 9 patients (75.0%). Postoperatively, mean (SD) FSH was 18.5 (17.8) mIU/mL (range = 0.7-53.6 mIU/mL), and remained elevated in 5 patients. LH remained elevated in 2 out of the 2 patients with elevated preoperative LH. 6 patients (50.0%) were prescribed testosterone gel postoperatively. 41.7% of patients did not report symptoms postoperatively.

Conclusion: All patients presented with elevated FSH levels, and a minority also had elevated LH or low testosterone. Surgery led to a reduction in symptomatic complaints in many cases, and the majority achieved gross total resection. Given that most patients continue to exhibit hormonal abnormalities postoperatively, close follow-up and thorough investigation of gonadal dysfunction is essential, as many patients may require ongoing medical management.

Keywords: FSH adenoma; Functional gonadotroph; Gonadotroph adenoma; Hypogonadism; LH adenoma; Pituitary adenoma; SF1 adenoma.