Prolactin Secreting Pituitary Microadenoma: Results of Transsphenoidal Surgery After Medical Therapy With Dopamine Agonist

Surgical Management of Giant Prolactinomas: A Descriptive Study

Introduction

Giant prolactinoma (GP) is a rare pituitary lactotropic cell tumor larger than 4 cm in its widest dimension, and is less likely than a smaller prolactinoma to achieve prolactin normalization on dopamine agonist (DA) monotherapy. There is a paucity of data on the circumstances and outcomes of second-line management of GP with surgery. Herein, our institution's experience with the surgical management of GPs is described.

Methods

A single-center retrospective analysis was conducted of patients who underwent surgery for giant prolactinoma from 2003 to 2018. A chart review was conducted for demographic data, clinical features, laboratory and radiographic findings, operative and pathology reports, perioperative management, and clinical outcomes in follow-up. Descriptive statistics were used.

Results

Of 79 prolactinoma cases, 8 patients had GP with a median age of 38 years (range 20-53), 75% (6/8) were male, with a median largest tumor dimension of 6 cm (range 4.6-7.7), and a median prolactin level of 2,500 μg/L (range 100->13,000). Six patients had transsphenoidal surgery for dopamine agonist (DA) resistance or intolerance. Two patients had a craniotomy for a missed diagnosis; one was due to the hook effect. No tumor resections were complete by either surgical approach; all had persistent hyperprolactinemia requiring postoperative DA therapy, and two patients had an additional craniotomy procedure for further tumor debulking. There was no recovery of pituitary axes and postoperative deficits were common. Remission as defined by prolactin normalization occurred in 63% (5/8) at a median time of 36 months (range 14-63 months) on DA therapy after surgery with a follow-up of 3-13 years.

Conclusions

GPs infrequently require surgical resection, which is generally incomplete and requires adjuvant therapy. Given the rarity of surgery for GPs, multi-institutional or registry studies would yield clearer guidance on optimal management.

Are dopamine agonists still the first-choice treatment for prolactinoma in the era of endoscopy? A systematic review and meta-analysis

Background

For prolactinoma patients, dopamine agonists (DAs) are indicated as the first-line treatment and surgery is an adjunctive choice. However, with the development of surgical technique and equipment, the effect of surgery has improved. The aim of this study was to assess the efficacy and safety of surgery versus DAs in patients with different types of prolactinomas.

Methods

A systematic search of literature using Web of Science, PubMed, Cochrane Library, and Clinical Trial databases was conducted until July 12, 2019. Prolactinoma patients treated with DAs (bromocriptine or cabergoline) or surgery (microscopic or endoscopic surgery) were included. Outcomes included the biochemical cure rate, recurrence rate, prolactin level, improvement rates of symptoms, and incidence rates of complications. A random-effects model was used to pool the extracted data. Qualitative comparisons were conducted instead of quantitative comparison.

Results

DAs were better than surgery in terms of the biochemical cure rate (0.78 versus 0.66), but surgery had a much lower recurrence rate (0.19 versus 0.57). Full advantages were not demonstrated in improvement rates of symptoms and incidence rates of complications with both treatment options. In microprolactinoma patients, the biochemical cure rate of endoscopic surgery was equal to the average cure rate of DAs (0.86 versus 0.86) and it surpassed the biochemical cure rate of bromocriptine (0.86 versus 0.76). In macroprolactinoma patients, endoscopic surgery was slightly higher than bromocriptine (0.66 versus 0.64) in terms of the biochemical cure rate.

Conclusion

For patients with clear indications or contraindications for surgery, choosing surgery or DAs accordingly is unequivocal. However, for patients with clinical equipoise, such as surgery, especially endoscopic surgery, in microprolactinoma and macroprolactinoma patients, we suggest that neurosurgeons and endocrinologists conduct high-quality clinical trials to address the clinical equipoise quantitatively.

Supplementary Information

The online version contains supplementary material available at 10.1186/s41016-022-00277-1.

Determinants of Surgical Remission in Prolactinomas: A Systematic Review and Meta-Analysis

OBJECTIVE

Prolactin-secreting tumors respond well to medical management, with a few patients requiring surgery. We conducted a systematic review and meta-analysis to study the determinants of surgical remission in these tumors.

METHODS

We searched PubMed to identify eligible studies reporting postoperative remission in patients treated with transsphenoidal surgery for prolactinoma. Primary outcomes included postoperative remission, follow-up remission, and recurrence. Postoperative and follow-up remission were defined as normoprolactinemia at <1 year and >1 year after operation, respectively. Recurrence was defined as hyperprolactinemia after initial normalization of prolactin levels. Odds ratios (ORs) were calculated, stratified by radiologic size, tumor extension, and tumor invasion, and analyzed using a random-effects model meta-analysis.

RESULTS

Thirty-five studies were included. Macroadenomas were associated with lower rates of postoperative remission (OR, 0.20; 95% confidence interval [CI], 0.16-0.24) and lower rates of remission at follow-up (OR, 0.11; 95% CI, 0.053-0.22). Postoperative remission was less likely in tumors with extrasellar or suprasellar extension (OR, 0.16; 95% CI, 0.06-0.43) and tumors with cavernous sinus invasion (OR, 0.03; 95% CI, 0.01-0.13). Female gender and absence of preoperative dopamine agonist treatment were also associated with higher remission rates. Across the included studies, there was considerable heterogeneity in each primary outcome (postoperative remission, I² = 94%; follow-up remission, I² = 86%; recurrence, I² = 68%).

CONCLUSIONS

Transsphenoidal surgery for prolactinomas may be particularly effective in small, noninvasive, treatment-naive tumors and may provide a viable first-line alternative to dopamine agonist therapy in such patients.

Intra-operative MRI vs endoscopy in achieving gross total resection of pituitary adenomas: a systematic review

BACKGROUND

Intraoperative magnetic resonance imaging (iMRI) is a technology that may improve rates of gross total resection (GTR) for pituitary adenomas. The endoscope is another less expensive technology, which also may maximize resection rates. A direct comparison of these approaches and their additive benefit has never been performed.

METHODS

A systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) standard. PubMed and Embase databases were searched for studies that examined GTR for pituitary adenoma resection with either endoscopic transsphenoidal surgery (eTSS), microscopic transsphenoidal surgery with iMRI (mTSS + iMRI), or endoscopic transsphenoidal surgery with iMRI (eTSS + iMRI).

RESULTS

Eighty-five studies that reported GTR rates in 7124 pituitary adenoma patients were identified. For all pituitary adenomas, eTSS had a pooled proportion of GTR of 68.9% (95% CI 64.7-73.0%) which was similar to that of mTSS + iMRI (GTR 68.3%; 95% CI = 59.4-76.5%) and eTSS + iMRI (GTR 70.7%; 95% CI = 56.9-89.6%). For the subgroup of pituitary macroadenomas, pooled proportions for GTR were similar between eTSS and mTSS + iMRI (eTSS: GTR 59.4%; 95% CI = 49.6-68.7% vs mTSS + iMRI: GTR 68.8%; 95% CI = 57.3-79.3%), and higher for eTSS + iMRI (81.1%; 95% CI = 75.5-86.2%). The post-operative CSF leak proportion for eTSS (4.7%; 95% CI = 3.6-5.9%) was similar to that for eTSS + iMRI (3.7%; 95% CI = 1.6-6.5%) and mTSS + iMRI (4.6%; 95% CI = 2.0-8.3%). No direct statistical comparisons could be performed.

CONCLUSION

Final GTR proportions are similar whether the surgeon uses a microscope supplemented with iMRI or endoscope with or without iMRI. The benefit of the two technologies may be complementary for macroadenomas. These findings are important to consider when comparing the efficacy of different technical strategies in the management of pituitary adenomas.