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

Abstract

OBJECTIVELoss 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.METHODSPatients 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.RESULTSOne 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.CONCLUSIONSRecovery 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.

Pituitary function after transsphenoidal surgery including measurement of basal morning cortisol as predictor of adrenal insufficiency

“…Furthermore, an overall beneficial effect on pituitary hormone secretion was found. The maximum numbers of post-surgery new insufficiencies per axis was 10% which is in accordance with previous papers reporting data on deterioration of pituitary function 20,21,24,27 . Analogous to other studies we identified tumour size as a predictor of post-surgery insufficiency for the 3 investigated pituitary axis 6,26,27 .…”

“…The median tumour size was 28 (17-33) mm. Men had larger tumours compared with women, 28 (23)(24)(25)(26)(27)(28)(29)(30)(31)(32)(33)(34)(35)(36) vs. 23 (15-31) mm, (p=0.022), respectively. Twelve of 15 patients with Cushings disease had a microadenoma, whereas 8/32 of acromegalic patients had a microadenoma (2 had unknown size).…”

Diabetes insipidus secondary to sellar/parasellar lesions

“…Rare cases of macroprolactinomas developing DI during pregnancy have been also described, although their exact pathogenesis was not completely delineated 72 . In a recent study, only 0.6% of 160 patients (a single patient) with non‐functional pituitary adenomas presented with pre‐operative DI 73 …”

“…• GH (n = 1) In a recent study, only 0.6% of 160 patients (a single patient) with non-functional pituitary adenomas presented with pre-operative DI. 73 LYH accounted for 26.5% of all sellar/parasellar tumours presenting with DI at diagnosis. Diabetes insipidus in LYH appears to be resistant to treatment 49 with only a small percentage of patients, approximately 10%, exhibiting recovery.…”

Pituitary non-functioning macroadenomas: If and when to recommend surgery

“…In both cases the non-endocrine complications of the tumours as eye field involvement or intense headache episode were suggestive for the mass effect (12). The required surgery in these cases has a relatively low rate of success depending of tumour features and neurosurgeon's experience (13). Re-surgery selective or not, or even trans-frontal approach must be taken into consideration in case of post-operatory persistent disease (14,15).…”