Microneurosurgery and subsequent gamma knife radiosurgery for functioning pituitary macroadenomas or giant adenomas: One institution’s experience

Comparison of Surgical Modalities for Giant Pituitary Adenoma: A Systematic Review and Meta-Analysis of 1413 Patients

BACKGROUND AND OBJECTIVES

Giant pituitary adenomas (GPAs) are a challenging clinical entity, composing 5% to 15% of all pituitary adenomas. While the endoscopic endonasal transsphenoidal (EET) approach has surpassed the microsurgical transsphenoidal (MT) and transcranial (TC) approaches as the first-line surgical modality in most institutions, a systematic review comparing the 3 approaches has not been undertaken since 2012. Given growing adoption of EET and development of novel operative techniques over the past decade, an updated comparison of GPA surgical modalities is warranted.

METHODS

We identified all studies related to the surgical management of GPAs in PubMed, Embase, and Web of Science from inception to December 31, 2021. End points assessed included gross total resection (GTR) rates, postoperative visual improvement, mortality, and perioperative complications.

RESULTS

After screening of 1701 studies, we identified 45 studies on the surgical management of GPAs for meta-analysis. Thirty-one used the EET approach (n = 1413), 11 studies used the MT approach (n = 601), and 10 used the TC approach (n = 416). The cumulative number of patients treated by EET did not exceed that of patients treated by the TC or MT approaches until 2014 and 2015, respectively. Despite patients undergoing EET having the highest average tumor diameter, pooled rates for GTR were significantly higher for EET (42%) than MT (33%, P < .001) and TC (8%, P < .001) and EET similarly exhibited superior rates of visual improvement (85%) than MT (73%, P < .001) and TC (56%, P < .001). Mortality rates were comparable between EET (0.6%) and MT (1.6%), but EET had significantly lower mortality than TC (2.7%, P < .001). Compared with MT, EET had lower rates of hypopituitarism (8.5% vs 14.9%, P = .012) but higher rates of diabetes insipidus (3.1% vs 0.5%, P = .001).

CONCLUSION

In an updated meta-analysis of 1413 patients with GPA, EET resection conferred significantly higher rates of visual improvement and GTR, when compared with the MT and TC approaches.

Functioning gonadotroph adenoma with hyperestrogenemia and ovarian hyperstimulation in a reproductive-aged woman: A case report and review of literature

BACKGROUND

Functioning gonadotroph adenomas are extremely rare pituitary tumors that secrete gonadotropins and exhibit distinct clinical manifestations. Here, we report a case of functioning gonadotroph adenoma in a reproductive-aged woman and discuss its diagnosis and management.

CASE SUMMARY

A 21-year-old female patient with abdominal pain, irregular menstruation, hyperestrogenemia, and an ovarian mass was included. Brain magnetic resonance imaging (MRI) revealed a pituitary macroadenoma, and transsphenoidal surgery relieved her clinical symptoms. Before transsphenoidal surgery, plasma CA125, estradiol levels were elevated, while prolactin, luteinizing hormone, follicle-stimulating hormone, PROG, cortisol, FT4, thyroid-stimulating hormone, parathyroid hormone, and GH levels were maintained at normal levels. After transsphenoidal surgery, the patient was diagnosed with a functioning gonadotroph adenoma. During follow-up, pelvic ultrasound confirmed normal-sized ovaries in the patient, the menstrual cycle returned to regular, and her hormones were maintained within a normal range. There was no evidence of tumor recurrence after two years of follow-up.

CONCLUSION

Early diagnosis of functioning gonadotroph adenomas should be considered in patients with hyperestrogenism, irregular menstruation, large or recurrent ovarian cysts, and visual field defects. Pituitary MRI should be performed, and transsphenoidal surgery is recommended for the management of this disease.

Change in cephalocaudal tumor cavity diameter after transsphenoidal surgery is a predictor of diabetes insipidus in pituitary adenoma

Objective

To assess the factors influencing the development of diabetes insipidus after transsphenoidal surgery for pituitary adenomas.

Methods

We retrospectively analyzed the clinical data of patients with pituitary adenoma who underwent transsphenoidal surgery. The pituitary gland was assessed using a 3.0 T magnetic resonance imaging, and the predictors of postoperative diabetes insipidus were determined through univariate and multivariate analyses.

Results

A total of 212 eligible patients with pituitary adenomas were included; 82 (38.7%) cases developed postoperative diabetes insipidus while 130 cases (61.3%) did not. Diabetes insipidus was transient in 80 (37.7%) patients and permanent in 2 (0.9%) patients. The results of logistic regression analyses showed that the change in cephalocaudal tumor cavity diameter after transsphenoidal surgery was associated with the occurrence of postoperative diabetes insipidus.

Conclusions

Change in cephalocaudal tumor cavity diameter after transsphenoidal surgery may play an important role in predicting diabetes insipidus onset in patients with a pituitary adenoma.

Treatment strategies for giant pituitary adenomas in the era of endoscopic transsphenoidal surgery: a multicenter series

OBJECTIVE

Given the anatomical complexity and frequently invasive growth of giant pituitary adenomas (GPAs), individually tailored approaches are required. The aim of this study was to assess the treatment strategies and outcomes in a large multicenter series of GPAs in the era of endoscopic transsphenoidal surgery (ETS).

METHODS

This was a retrospective case-control series of 64 patients with GPAs treated at two tertiary care centers by surgeons with experience in ETS. GPAs were defined by a maximum diameter of ≥ 4 cm and a volume of ≥ 10 cm3 on preoperative isovoxel contrast-enhanced MRI.

RESULTS

The primary operation was ETS in all cases. Overall gross-total resection rates were 64% in round GPAs, 46% in dumbbell-shaped GPAs, and 8% in multilobular GPAs (p < 0.001). Postoperative outcomes were further stratified into two groups based on extent of resection: group A (gross-total resection or partial resection with intracavernous remnant; 21/64, 33%) and group B (partial resection with intracranial remnant; 43/64, 67%). Growth patterns of GPAs were mostly round (11/14, 79%) in group A and multilobular (33/37, 89%) in group B. In group A, no patients required a second operation, and 2/21 (9%) were treated with adjuvant radiosurgery. In group B, early transcranial reoperation was required in 6/43 (14%) cases due to hemorrhagic transformation of remnants. For the remaining group B patients with remnants, 5/43 (12%) underwent transcranial surgery and 12/43 (28%) underwent delayed second ETS. There were no deaths in this series. Severe complications included stroke (6%), meningitis (6%), hydrocephalus requiring shunting (6%), and loss or distinct worsening of vision (3%). At follow-up (mean 3 years, range 0.5-16 years), stable disease was achieved in 91% of cases.

CONCLUSIONS

ETS as a primary treatment modality to relieve mass effect in GPAs and extent of resection are dependent on GPA morphology. The pattern of residual pituitary adenoma guides further treatment strategies, including early transcranial reoperation, delayed endoscopic transsphenoidal/transcranial reoperation, and adjuvant radiosurgery.

Management of giant prolactinoma causing craniocervical instability: illustrative case

BACKGROUND

Giant prolactinomas (>4 cm) are a rare entity, constituting less than 1% of all pituitary tumors. Diagnosis can usually be achieved through endocrinological analysis, but biopsy may be considered when trying to differentiate between invasive nonfunctioning pituitary adenomas and primary clival tumors such as chordomas.

OBSERVATIONS

The authors presented a rare case of a giant prolactinoma causing significant clival and occipital condyle erosion, which led to craniocervical instability. They provided a review of the multimodal management. Management involved medical therapy with dopamine agonists, and surgery was reserved for acute neural compression or dopamine agonist resistance, with the caveat that surgery was extremely unlikely to lead to normalization of serum prolactin in dopamine agonist-resistant tumors.

LESSONS

Adjunctive surgical therapy may be necessary in cases of skull base erosion, particularly when erosion or pathological fractures involve the occipital condyles. Modern posterior occipital-cervical fusion techniques have high rates of arthrodesis and can lead to symptomatic improvement. This procedure should be considered early in the multimodal approach to giant prolactinomas because of the often dramatic response to medical therapy and potential for further craniocervical instability.

Effect of Stereotactic Radiosurgery on Residual or Relapsed Pituitary Adenoma: A Systematic Review and Meta-Analysis

BACKGROUND

In pituitary tumors, the presence of residual tumor after transsphenoidal surgery and recurrence of the tumor after resection are frequent, and the best treatment is not well established. The effects and complications of stereotactic radiosurgery have not been extensively studied.

OBJECTIVE

We aimed to reveal the effect of stereotactic radiosurgery on residual and recurrent adenomas.

METHODS

A systematic review of the literature in the MEDLINE/PubMed, Cochrane Central Database, and Google Scholar was conducted using the criteria of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. The search was structured according to the PICOT (i.e., Participants, types of Interventions, Comparator between the treatments, types of Outcome measures, and Follow-up [Time of duration]) strategy. The methodologic quality assessment (risk of bias) was performed according to the Methodological Index for Non-Randomized Studies scale. The studies were grouped and analyzed after data extraction using the software "R".

RESULTS

Twenty-six articles including 2315 patients were analyzed, with an average follow-up duration of 57.8 months and mean radiation marginal dose of 19.6 Gy. The overall tumor control rate was 95%, tumor reduction rate was 46%, and hormonal control rate was 67%. The side effects were evaluated.

CONCLUSIONS

Stereotactic radiosurgery was efficient in residual or recurrence tumor control, with few side effects, and is recommended for treating residual or recurrent tumors, both secreting and nonsecreting tumors. A limitation of this study is that there were no randomized trials included in the synthesis.

Debulking surgery of pituitary adenoma as a strategy to facilitate definitive stereotactic radiosurgery

In patients with pituitary adenomas (PA) who are unable to undergo complete surgical resection, radiation therapy (RT), specifically stereotactic radiosurgery (SRS), results in excellent local control. However, the utility of radiosurgery may be limited by the proximity of the lesion to the optic chiasm (OC). We evaluate the efficacy of debulking surgery in increasing the PA-OC separation to convert patients into SRS candidates. From 2007 to 2015, 31 patients with PA < 2 mm from the OC underwent debulking surgery followed by RT within 2 years of resection. Coronal and sagittal T1-pre- and post-contrast sequences were used to determine PA-OC separation. Time interval between postoperative and pre-radiotherapy MRI scans and type of radiation therapy were analyzed. Functional tumor status, tumor characteristics [cavernous sinus (CS) or suprasellar (SS) involvement, chiasm/nerve encasement (NE)], and presence of ≥ 2 of these characteristics (multiple factors, MF) was also noted. Surgery converted 9 of 31 patients (29%) to SRS candidates. Median time from surgery to pre-RT planning MRI was 8 months (range 2-20). Of the 31 patients initially ineligible for SRS, 6 became eligible immediately after surgery, and another 3 were deemed eligible on follow-up. Mean PA-OC separation was 0.3 mm preoperative, 1.4 mm postoperative, and 2.1 mm at time of SRS (p = 0.002). Preoperative SS, NE, and MF involvement predicted pre-RT separation < 2 mm. Debulking surgery of unresectable pituitary tumors is a successful strategy for converting select radiosurgery-ineligible patients to radiosurgery candidates. Absence of preoperative SS, NE, and MF predicts for successful conversion.