Serial Re-Expansion of Pituitary Gland Is Associated with Endocrinologic Recovery

Early hormonal recovery following endoscopic transsphenoidal surgery for silent non-functioning pituitary adenomas with hormone dysfunction

PURPOSE

The role of transsphenoidal surgery in the recovery of preexisting hormone dysfunction from pituitary tumors remains controversial. This study aimed to investigate the incidence of hormone dysfunction among asymptomatic non-functioning pituitary adenomas and their recovery following endoscopic transsphenoidal surgery.

METHODS

Eligibility criteria included age under 80 years, presence of a non-functioning pituitary adenoma compressing the normal gland resulting in deviation of the stalk, absence of visual symptoms, and availability for regular follow-up using MRI and pre- and post-operative endocrinological assessments. 182 patients with silent non-functioning pituitary adenomas were included in this study between March 2014 and December 2018. All patients underwent endoscopic transsphenoidal surgery and complete hormonal evaluation, with basal hormone assays and a combined pituitary function test before and after surgery until the end of last follow-up.

RESULTS

Preoperative assessment of hormonal function revealed that 124 of 182 patients (68.1%) had at least a single hormone dysfunction preoperatively. Among these, 61 of 124 (49.2%) had a dysfunction in a single axis, and 63 (50.8%) had a hormone dysfunction in two or more axes. Overall, the median endocrinological follow-up duration was 15.0 months (6-57 months). At 1 month following surgery, 91 patients (73.4%) with hormone dysfunction experienced improvement in at least a single hormone axis. Prolactin was the most common hormone among those that recovered at the last follow up (92.8% improvement) followed by growth hormone (GH, 50.0%), thyroid stimulating hormone (TSH, 50.0%), gonadotropin (Gn, 46.9%), and adrenocorticotropic hormone (ACTH, 45.0%). Time to recovery varied from 1.1 months (for prolactin) to 2.2 months (for gonadotropin, and ACTH). In patients with preoperative deficiency in GH, and ACTH, postoperative transient diabetes insipidus was associated with poor recovery (GH: HR = 0.50, p = 0.048; ACTH: HR = 0.39, p = 0.023).

CONCLUSIONS

Non-functioning pituitary adenomas with silent hormone dysfunction are often overlooked by clinicians and patients. We suggest that even silent hormone dysfunction in patients with non-functioning pituitary adenomas can be improved with effective surgical decompression and these tumors may be potential indications of endoscopic transsphenoidal surgery.

Endocrine function and gland volume after endoscopic transsphenoidal surgery for nonfunctional pituitary macroadenomas

OBJECTIVE

Loss of pituitary function due to nonfunctional pituitary adenoma (NFPA) may be due to compression of the pituitary gland. It has been proposed that the size of the gland and relative perioperative gland expansion may relate to recovery of pituitary function, but the extent of this is unclear. This study aims to assess temporal changes in hormonal function after transsphenoidal resection of NFPA and the relationship between gland reexpansion and endocrine recovery.

METHODS

Patients who underwent endoscopic transsphenoidal surgery by a single surgeon for resection of a nonfunctional macroadenoma were selected for inclusion. Patients with prior pituitary surgery or radiosurgery were excluded. Patient characteristics and endocrine function were extracted by chart review. Volumetric segmentation of the pre- and postoperative (≥ 6 months) pituitary gland was performed using preoperative and long-term postoperative MR images. The relationship between endocrine function over time and clinical attributes, including gland volume, were examined.

RESULTS

One hundred sixty eligible patients were identified, of whom 47.5% were female; 56.9% of patients had anterior pituitary hormone deficits preoperatively. The median tumor diameter and gland volume preoperatively were 22.5 mm (interquartile range [IQR] 18.0-28.8 mm) and 0.18 cm3 (IQR 0.13-0.28 cm3), respectively. In 55% of patients, endocrine function normalized or improved in their affected axes by median last clinical follow-up of 24.4 months (IQR 3.2-51.2 months). Older age, male sex, and larger tumor size were associated with likelihood of endocrine recovery. Median time to recovery of any axis was 12.2 months (IQR 2.5-23.9 months); hypothyroidism was the slowest axis to recover. Although the gland significantly reexpanded from preoperatively (0.18 cm3, IQR 0.13-0.28 cm3) to postoperatively (0.33 cm3, IQR 0.23-0.48 cm3; p < 0.001), there was no consistent association with improved endocrine function.

CONCLUSIONS

Recovery of endocrine function can occur several months and even years after surgery, with more than 50% of patients showing improved or normalized function. Tumor size, and not gland volume, was associated with preserved or recovered endocrine function.

Intraoperative unfolding and postoperative pruning of the pituitary gland after transsphenoidal surgery for pituitary adenoma: A volumetric and endocrinological evaluation

PURPOSE

To describe the volumetric changes that the pituitary gland (PG) undergoes during and after transsphenoidal surgery (TSS), and to evaluate if unfolding and/or pruning are related to endocrinological outcome measures.

METHODS

Retrospective evaluation of data prospectively collected of a cohort of patients undergoing TSS for a pituitary adenoma with the adjunctive use of high field 3 Tesla intraoperative MRI. All patients underwent a full endocrinological workup preoperatively, as well as at 6 weeks and 1 year postoperatively. A decrease in PG volume ≥15% between the intraoperative and 3-month, or between the 3-month and 12-month measurements, was considered early and late pruning, respectively.

RESULTS

The PG unfolds significantly during TSS, and subsequently undergoes pruning up until 1 year postoperatively, in most cases returning to the preoperatively measured PG volume. A smaller baseline PG volume predicts intraoperative unfolding. Early pruning of the PG after surgery was associated with new functional deficits. Baseline pituitary compression also correlated to newly occurring deficits after surgery. A larger 1-year pituitary volume was associated with biochemical remission in secreting adenomas.

CONCLUSIONS

The PG shows dynamic change during and after TSS for pituitary adenoma. Small baseline and 3-month PG volumes, as well as early pruning were independently associated with new deficits. Our findings warrant prospective validation in a larger cohort with higher statistical power.