Medical Student University of California, San Francisco, School of Medicine San Francisco, California, United States
Introduction: Temporal trends in postoperative prolactin values after transsphenoidal resection of a prolactinoma remain understudied and could be of value to physicians planning follow-up treatment.
Methods: A retrospective review of 210 prolactinomas operated on between 1977-2020 yielded 103 patients with postoperative prolactin follow-up. Hyperprolactinemia was defined as >20ng/mL for males and >25ng/mL for females.
Results: We defined 3 groups of patients based on immediate postoperative day one prolactin: (1) Low normal patients (n=59, 57.3%) with prolactin in the lower half of normal (mean, range: 3.15ng/mL, 0.3-12.3ng/mL) (2) High normal patients (n=15, 14.6%) with prolactin in the upper half of normal (mean, range: 15.93ng/mL, 12.5-24.1ng/mL); and (3) Mildly hyperprolactinemic patients (n=12, 11.7%) with prolactins 20-60ng/mL for males and 25-75ng/mL for females (mean, range: 47.6ng/mL, 30.4-66.1ng/mL). Patients with hyperprolactinemia above the mild thresholds (n=17, 16.5%) were excluded from analysis. Mean (SD) age was 35.0 (9.5) years, 77.9% were female, and 55.8% utilized dopamine agonists preoperatively; and these variables did not significantly differ by group. The three groups (low normal vs. high normal vs. mildly hyperprolactinemic) did differ in macroadenoma prevalence (42.4% % vs. 66.7% vs. 91.2%; p< 0.01). At >6 weeks, follow-up MRIs and prolactins revealed 16.9% vs. 60% vs. 100% (p < 0.01) exhibiting hyperprolactinemia and/or requiring dopamine agonists for the low normal, high normal, and mildly hyperprolactinemic groups respectively. Residual prolactinoma prevalence was 8.5% vs. 20.0% vs. 58.3% (p < 0.01) and postoperative radiation treatment prevalence was 3.4% vs. 6.7% vs. 25% (p=0.03) for the low normal, high normal, and mildly hyperprolactinemic groups respectively.
Conclusion : Immediate postoperative prolactins on postoperative day one and their degree of normalization are associated with long-term biochemical remission. It is important for physicians to follow-up with patients that exhibit higher postoperative day one prolactins as these patients are at higher risk for long-term hyperprolactinemia and residual prolactinoma.
